Tag Archives: Instrumentation and Detectors

Fieldable muon spectrometer using multi-layer pressurized gas Cherenkov radiators and its applications [CL]

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http://arxiv.org/abs/2201.00253


Cosmic ray muons have been considered as a non-conventional radiation probe in various applications. To utilize cosmic ray muons in engineering applications, two important quantities, trajectory and momentum, must be known. The muon trajectories are easily reconstructed using two-fold detector arrays with a high spatial resolution. However, precise measurement of muon momentum is difficult to be achieved without deploying large and expensive spectrometers such as solenoid magnets. Here, we propose a new method to estimate muon momentum using multi-layer pressurized gas Cherenkov radiators. This is accurate, portable, compact (< 1m3), and easily coupled with existing muon detectors without the need of neither bulky magnetic nor time-of-flight spectrometers. The results show that not only our new muon spectrometer can measure muon momentum with a resolution of +-0.5 GeV/c in a momentum range of 0.1 to 10.0 GeV/c, but also we can reconstruct cosmic muon spectrum with high accuracy (~90%).

Read this paper on arXiv…

J. Bae and S. Chatzidakis
Tue, 4 Jan 22
3/58

Comments: N/A

Impact of the superconductors properties on the measurement sensitivity of resonant-based axion detectors [CL]

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http://arxiv.org/abs/2112.12775


Axions, hypothetical particles theorized to solve the strong CP-problem, are presently being considered as strong candidates as cold dark matter constituents. The signal power of resonant-based axion detectors, known as haloscopes, is directly proportional to their quality factor $Q$. In this paper, the impact of the use of superconductors in the performances of the haloscopes is studied by evaluating the obtainable $Q$. In particular, the surface resistance $R_s$ of NbTi, Nb$3$Sn, YBa$_2$Cu$_3$O${7-\delta}$ and FeSe${0.5}$Te${0.5}$ is computed in the frequency, magnetic field and temperature ranges of interest, starting from the measured vortex motion complex resistivity and screening lengths of these materials. From $R_s$ the quality factor $Q$ of a cylindrical haloscope with copper conical bases and superconductive lateral wall, operating with the TM${010}$ mode, is evaluated and used to perform a comparison of the performances of the different materials. Both YBa$_2$Cu$_3$O${7-\delta}$ and FeSe${0.5}$Te${0.5}$ are shown to improve the measurement sensitivity by almost an order of magnitude with respect to a whole Cu cavity, while NbTi is shown to be suitable only at lower frequencies (<10 GHz). Nb$_3$Sn can give an intermediate improvement in the whole spectrum of interest.

Read this paper on arXiv…

A. Alimenti, K. Torokhtii, D. Gioacchino, et. al.
Fri, 24 Dec 21
9/58

Comments: 15 pages, 5 figures, submitted to Instruments journal (published by MDPI)

Gadolinium Loaded Cherenkov Detectors for Neutron Monitoring in High Energy Air Showers [CL]

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http://arxiv.org/abs/2112.12739


Monitoring of high energy cosmic ray neutrons is of particular interest for cosmic ray water Cherenkov detectors as intense bundles of delayed neutrons have been found to arrive after the initial passage of a high energy air shower. In this paper we explore the possibility of building large-area high-energy neutron monitors using gadolinium-loaded Water Cherenkov Detectors (WCDs). GEANT4 simulations of photon production in WCDs are used to estimate the maximum detection efficiency for a hypothetical system. Requiring a series of neutron induced gamma ray flashes distributed over an extended period of time (up to 20{\mu}s) was shown to be an effective way to discriminate high energy neutron interactions from other backgrounds. Results suggest that neutron detection efficiencies of 4-15% may be possible using a gadolinium-loaded detection system above 200 MeV. The magnitude of gadolinium loading was also shown to significantly modify the timing response of the simulated detector.

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P. Stowell, S. Fargher, L. Thompson, et. al.
Fri, 24 Dec 21
10/58

Comments: 12 Pages, 8 Figures

The Wavelength-shifting Optical Module [IMA]

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http://arxiv.org/abs/2112.12258


The Wavelength-shifting Optical Module (WOM) is a novel photosensor concept for the instrumentation of large detector volumes with single-photon sensitivity. The key objective is to improve the signal-to-noise ratio which is achieved by decoupling the photosensitive area of a sensor from the cathode area of its photomultiplier tube (PMT).
The WOM consists of a transparent tube with two PMTs attached to its ends. The tube is coated with wavelength-shifting paint absorbing ultra-violet photons with nearly $100\,\%$ efficiency. Depending on the environment, e.g. air (ice), up to $73\,\%$ $(41\,\%)$ of the subsequently emitted optical photons can be captured by total internal reflection and propagate towards the PMTs where they are recorded.
The optical properties of the paint, the geometry of the tube and the coupling of the tube to the PMTs have been optimized for maximal sensitivity based on theoretical derivations and experimental evaluations. Prototypes were built to demonstrate the technique and to develop a reproducible construction process.
Important measurable characteristics of the WOM are the wavelength dependent effective area, the transit time spread of detected photons and the signal-to-noise ratio. The WOM outperforms bare PMTs especially with respect to the low signal-to-noise ratio with an increase of a factor up to 8.9 in air (5.2 in ice). Since the gain in sensitivity is mostly in the UV-regime, the WOM is an ideal sensor for Cherenkov and scintillation detectors.

Read this paper on arXiv…

B. Bastian-Querner, L. Binn, S. Böser, et. al.
Fri, 24 Dec 21
26/58

Comments: Submitted to Sensors, 20 pages

Experimental verification of inter-satellite clock synchronization at LISA performance levels [IMA]

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http://arxiv.org/abs/2112.12586


The Laser Interferometer Space Antenna (LISA) aims to observe gravitational waves in the mHz regime over its 10-year mission time. LISA will operate laser interferometers between three spacecrafts. Each spacecraft will utilize independent clocks which determine the sampling times of onboard phasemeters to extract the interferometric phases and, ultimately, gravitational wave signals. To suppress limiting laser frequency noise, signals sampled by each phasemeter need to be combined in post-processing to synthesize virtual equal-arm interferometers. The synthesis in turn requires a synchronization of the independent clocks. This article reports on the experimental verification of a clock synchronization scheme down to LISA performance levels using a hexagonal optical bench. The development of the scheme includes data processing that is expected to be applicable to the real LISA data with minor modifications. Additionally, some noise coupling mechanisms are discussed.

Read this paper on arXiv…

K. Yamamoto, C. Vorndamme, O. Hartwig, et. al.
Fri, 24 Dec 21
56/58

Comments: 9 pages, 4 figures

Impact of the superconductors properties on the measurement sensitivity of resonant-based axion detectors [CL]

Posted on by

http://arxiv.org/abs/2112.12775


Axions, hypothetical particles theorized to solve the strong CP-problem, are presently being considered as strong candidates as cold dark matter constituents. The signal power of resonant-based axion detectors, known as haloscopes, is directly proportional to their quality factor $Q$. In this paper, the impact of the use of superconductors in the performances of the haloscopes is studied by evaluating the obtainable $Q$. In particular, the surface resistance $R_s$ of NbTi, Nb$3$Sn, YBa$_2$Cu$_3$O${7-\delta}$ and FeSe${0.5}$Te${0.5}$ is computed in the frequency, magnetic field and temperature ranges of interest, starting from the measured vortex motion complex resistivity and screening lengths of these materials. From $R_s$ the quality factor $Q$ of a cylindrical haloscope with copper conical bases and superconductive lateral wall, operating with the TM${010}$ mode, is evaluated and used to perform a comparison of the performances of the different materials. Both YBa$_2$Cu$_3$O${7-\delta}$ and FeSe${0.5}$Te${0.5}$ are shown to improve the measurement sensitivity by almost an order of magnitude with respect to a whole Cu cavity, while NbTi is shown to be suitable only at lower frequencies (<10 GHz). Nb$_3$Sn can give an intermediate improvement in the whole spectrum of interest.

Read this paper on arXiv…

A. Alimenti, K. Torokhtii, D. Gioacchino, et. al.
Fri, 24 Dec 21
10/58

Comments: 15 pages, 5 figures, submitted to Instruments journal (published by MDPI)

Experimental verification of inter-satellite clock synchronization at LISA performance levels [IMA]

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http://arxiv.org/abs/2112.12586


The Laser Interferometer Space Antenna (LISA) aims to observe gravitational waves in the mHz regime over its 10-year mission time. LISA will operate laser interferometers between three spacecrafts. Each spacecraft will utilize independent clocks which determine the sampling times of onboard phasemeters to extract the interferometric phases and, ultimately, gravitational wave signals. To suppress limiting laser frequency noise, signals sampled by each phasemeter need to be combined in post-processing to synthesize virtual equal-arm interferometers. The synthesis in turn requires a synchronization of the independent clocks. This article reports on the experimental verification of a clock synchronization scheme down to LISA performance levels using a hexagonal optical bench. The development of the scheme includes data processing that is expected to be applicable to the real LISA data with minor modifications. Additionally, some noise coupling mechanisms are discussed.

Read this paper on arXiv…

K. Yamamoto, C. Vorndamme, O. Hartwig, et. al.
Fri, 24 Dec 21
30/58

Comments: 9 pages, 4 figures

Gadolinium Loaded Cherenkov Detectors for Neutron Monitoring in High Energy Air Showers [CL]

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http://arxiv.org/abs/2112.12739


Monitoring of high energy cosmic ray neutrons is of particular interest for cosmic ray water Cherenkov detectors as intense bundles of delayed neutrons have been found to arrive after the initial passage of a high energy air shower. In this paper we explore the possibility of building large-area high-energy neutron monitors using gadolinium-loaded Water Cherenkov Detectors (WCDs). GEANT4 simulations of photon production in WCDs are used to estimate the maximum detection efficiency for a hypothetical system. Requiring a series of neutron induced gamma ray flashes distributed over an extended period of time (up to 20{\mu}s) was shown to be an effective way to discriminate high energy neutron interactions from other backgrounds. Results suggest that neutron detection efficiencies of 4-15% may be possible using a gadolinium-loaded detection system above 200 MeV. The magnitude of gadolinium loading was also shown to significantly modify the timing response of the simulated detector.

Read this paper on arXiv…

P. Stowell, S. Fargher, L. Thompson, et. al.
Fri, 24 Dec 21
37/58

Comments: 12 Pages, 8 Figures

The Wavelength-shifting Optical Module [IMA]

Posted on by

http://arxiv.org/abs/2112.12258


The Wavelength-shifting Optical Module (WOM) is a novel photosensor concept for the instrumentation of large detector volumes with single-photon sensitivity. The key objective is to improve the signal-to-noise ratio which is achieved by decoupling the photosensitive area of a sensor from the cathode area of its photomultiplier tube (PMT).
The WOM consists of a transparent tube with two PMTs attached to its ends. The tube is coated with wavelength-shifting paint absorbing ultra-violet photons with nearly $100\,\%$ efficiency. Depending on the environment, e.g. air (ice), up to $73\,\%$ $(41\,\%)$ of the subsequently emitted optical photons can be captured by total internal reflection and propagate towards the PMTs where they are recorded.
The optical properties of the paint, the geometry of the tube and the coupling of the tube to the PMTs have been optimized for maximal sensitivity based on theoretical derivations and experimental evaluations. Prototypes were built to demonstrate the technique and to develop a reproducible construction process.
Important measurable characteristics of the WOM are the wavelength dependent effective area, the transit time spread of detected photons and the signal-to-noise ratio. The WOM outperforms bare PMTs especially with respect to the low signal-to-noise ratio with an increase of a factor up to 8.9 in air (5.2 in ice). Since the gain in sensitivity is mostly in the UV-regime, the WOM is an ideal sensor for Cherenkov and scintillation detectors.

Read this paper on arXiv…

B. Bastian-Querner, L. Binn, S. Böser, et. al.
Fri, 24 Dec 21
47/58

Comments: Submitted to Sensors, 20 pages

Prospects of charge signal analyses in liquid xenon TPCs with proportional scintillation in the liquid phase [CL]

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http://arxiv.org/abs/2112.11844


As liquid xenon TPCs increase in target mass while pursuing the direct detection of WIMP dark matter, the technical challenges arising due to their size call for new solutions and open the discussion on alternative detector concepts. Proportional scintillation in liquid xenon allows for a single-phase design evading all problems related to the liquid-gas interface and the precise gas gap required in a dual-phase TPC. Aside from a different scintillation mechanism, the successful detection- and analysis scheme of state-of-the-art experiments is maintained in this approach. We study the impact on charge signal analysis in a single-phase detector of DARWIN dimensions, where the fast timing of the proportional scintillation signal allows for the precise identification of the single electrons in the ionisation signal. Such a discrete electron-counting approach leads to a better signal resolution for low energies when compared to the classical dual-phase continuous method. The absence of the liquid-gas interface further benefits the S2-only energy resolution significantly. This reduces the uncertainties from the scintillation and signal-detection process to a level significantly below the irreducible fluctuation in the primary ionisation. Exploiting the precise electron time information further allows for a powerful single vs.~multiple site interaction discrimination with 93% rejection efficiency and 98% signal acceptance. This outperforms the design goal of the DARWIN observatory by a reduction factor of 4.2 in non-rejected multiple site neutron events.

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F. Kuger, J. Dierle, H. Fischer, et. al.
Thu, 23 Dec 21
46/63

Comments: N/A

MICROSCOPE: systematic errors [IMA]

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http://arxiv.org/abs/2112.10559


The MICROSCOPE mission aims to test the Weak Equivalence Principle (WEP) in orbit with an unprecedented precision of 10$^{-15}$ on the E\”otv\”os parameter thanks to electrostatic accelerometers on board a drag-free micro-satellite. The precision of the test is determined by statistical errors, due to the environment and instrument noises, and by systematic errors to which this paper is devoted. Systematic error sources can be divided into three categories: external perturbations, such as the residual atmospheric drag or the gravity gradient at the satellite altitude, perturbations linked to the satellite design, such as thermal or magnetic perturbations, and perturbations from the instrument internal sources. Each systematic error is evaluated or bounded in order to set a reliable upper bound on the WEP parameter estimation uncertainty.

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M. Rodrigues, P. Touboul1, G. Metris, et. al.
Tue, 21 Dec 21
7/86

Comments: To be released in CQG MICROSCOPE Special Edition

Studies of VERITAS Photomultipliers After Eight Years of Use [IMA]

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http://arxiv.org/abs/2112.10707


The VERITAS gamma-ray telescope array has been operating since 2007 and has been equipped with Hamamatsu R10560-100-20 PMTs since 2012. A decision to continue operations into the mid 2020s was taken in 2019 so the question of whether the PMTs would need replacing became important and a study was initiated.
We present results from scanning two groups of 20 Hamamatsu R10560-100-20 PMTs with an LED flasher. One group comprised five PMTs from each of the four VERITAS telescopes and the other was made up of 20 PMTs of the same type, and date of manufacture, that had never been used. We measured three test variables related to gains and high-voltage response and found that there were no significant differences between the two groups. This indicates that there has been little ageing in the PMTs that have been used on the telescopes and that replacement is unnecessary.

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D. Hanna, S. Obrien and T. Rosin
Tue, 21 Dec 21
31/86

Comments: N/A

PICOLON dark matter search project [IMA]

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http://arxiv.org/abs/2112.10116


PICOLON (Pure Inorganic Crystal Observatory for LOw-energy Neutr(al)ino) aims to search for cosmic dark matter by high purity NaI(Tl) scintillator. We developed extremely pure NaI(Tl) crystal by hybrid purification method. The recent result of $^{210}$Pb in our NaI(Tl) is less than 5.7 $\mu$Bq/kg. We will report the test experiment in the low-background measurement at Kamioka Underground Laboratory. The sensitivity for annual modulating signals and finding dark matter particles will be discussed.

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K. Fushimi, D. Chernyak, H. Ejiri, et. al.
Tue, 21 Dec 21
63/86

Comments: To be published in the Proceedings of TAUP2021. (Journal of Physics: Conference Series (JPCS),)

Background model of Phoswich X-ray detector on board small balloon [IMA]

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http://arxiv.org/abs/2112.07944


We performed a detailed modelling of the background counts observed in a phoswich scintillator X-ray detector at balloon altitude, used for astronomical observations, on board small scientific balloon. We used Monte Carlo simulation technique in Geant4 simulation environment, to estimate the detector background from various plausible sources. High energy particles and radiation generated from the interaction of Galactic Cosmic Rays with the atmospheric nuclei is a major source of background counts (under normal solar condition) for such detectors. However, cosmogenic or induced radioactivity in the detector materials due to the interaction of high energy particles and natural radioactive contamination present in the detector can also contribute substantially to the detector background. We considered detailed 3D modelling of the earth’s atmosphere and magnetosphere to calculate the radiation environment at the balloon altitude and deployed a proper mass model of the detector to calculate the background counts in it. The calculation satisfactorily explains the observed background in the detector at 30 km altitude (atmospheric depth: 11.5 $g/cm^{2}$) during the balloon flight experiment from a location near 14.5$^{\circ}$N geomagnetic latitude.

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A. Roy, R. Sarkar and S. Chakrabarti
Thu, 16 Dec 21
50/83

Comments: 28 pages, 8 figures

Scintillation and optical properties of xenon-doped liquid argon [CL]

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http://arxiv.org/abs/2112.07427


Liquid argon (LAr) is a common choice as detection medium in particle physics and rare-event searches. Challenges of LAr scintillation light detection include its short emission wavelength, long scintillation time and short attenuation length. The addition of small amounts of xenon to LAr is known to improve the scintillation and optical properties. We present a characterization campaign on xenon-doped liquid argon (XeDLAr) with target xenon concentrations ranging from 0 to 300 ppm by mass encompassing the measurement of the photoelectron yield $Y$ , effective triplet lifetime $\tau_3$ and effective attenuation length $\lambda_\mathrm{att}$. The measurements were conducted in the Subterranean Cryogenic ARgon Facility, SCARF, a 1 t (XeD)LAr test stand in the shallow underground laboratory (UGL) of TU-Munich. These three scintillation and optical parameters were observed simultaneously with a single setup, the Legend Liquid Argon Monitoring Apparatus, LLAMA. The actual xenon concentrations in the liquid and gaseous phases were determined with the Impurity DEtector For Investigation of Xenon, IDEFIX, a mass spectrometer setup, and successful doping was confirmed. At the highest dopant concentration we find a doubling of $Y$ , a tenfold reduction of $\tau_3$ to $\sim$ 90 ns and a tenfold increase of $\lambda_{att}$ to over 6 m.

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C. Vogl, M. Schwarz, X. Stribl, et. al.
Wed, 15 Dec 21
70/85

Comments: N/A

R&D of Wavelength-Shifting Reflectors and Characterization of the Quantum Efficiency of Tetraphenyl Butadiene and Polyethylene Naphthalate in Liquid Argon [CL]

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http://arxiv.org/abs/2112.06675


Detectors based on liquid argon (LAr) often require surfaces that can shift vacuum ultraviolet (VUV) light and reflect the visible shifted light. For the LAr instrumentation of the LEGEND-200 neutrinoless double beta decay experiment, several square meters of wavelength-shifting reflectors (WLSR) were prepared: the reflector Tetratex (TTX) was in-situ evaporated with the wavelength shifter tetraphenyl butadiene (TPB). For even larger detectors, TPB evaporation will be more challenging and plastic films of polyethylene naphthalate (PEN) are considered as an option to ease scalability.
In this work, we first characterized the absorption (and reflectivity) of PEN, TPB (and TTX) films in response to visible light. We then measured TPB and PEN coupled to TTX in a LAr setup equipped with a VUV sensitive photomultiplier tube. The effective light yield in the setup was first measured using an absorbing reference sample, and the VUV reflectivity of TTX quantified. The characterization and simulation of the setup along with the measurements and modelling of the optical parameters of TPB, PEN and TTX allowed to estimate the quantum efficiency (QE) of TPB and PEN in LAr (at 87K) for the first time: these were found to be above 67% and 49%, respectively (at 90% CL). These results provide relevant input for the optical simulations of experiments that use TPB in LAr, such as LEGEND-200, and for experiments that plan to use TPB or PEN to shift VUV scintillation light.

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G. Araujo, L. Baudis, N. McFadden, et. al.
Tue, 14 Dec 21
8/98

Comments: N/A

Material radiopurity control in the XENONnT experiment [CL]

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http://arxiv.org/abs/2112.05629


The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and $^{222}$Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background ($\sim$17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected $^{222}$Rn activity concentration in XENONnT is determined to be 4.2$\,(^{+0.5}_{-0.7})\,\mu$Bq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.

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E. Aprile, K. Abe, F. Agostini, et. al.
Mon, 13 Dec 21
43/70

Comments: N/A

A kinetic inductance detectors array design for high background conditions at 150 GHz [IMA]

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http://arxiv.org/abs/2112.05365


We present a design for an array of kinetic inductance detectors (KIDs) integrated with phased array antennas for imaging at 150 GHz under high background conditions. The microstrip geometry KID detectors are projected to achieve photon noise limited sensitivity with larger than 100 pW absorbed optical power. Both the microstrip KIDs and the antenna feed network make use of a low-loss amorphous silicon dielectric. A new aspect of the antenna implementation is the use of a NbTiN microstrip feed network to facilitate impedance matching to the 50 Ohm antenna. The array has 256 pixels on a 6-inch wafer and each pixel has two polarizations with two Al KIDs. The KIDs are designed with a half wavelength microstrip transmission line with parallel plate capacitors at the two ends. The resonance frequency range is 400 to 800 MHz. The readout feedline is also implemented in microstrip and has an impedance transformer from 50 Ohm to 9 Ohm at its input and output.

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S. Shu, J. Sayers and P. Day
Mon, 13 Dec 21
50/70

Comments: 6 pages, 3 figures, submitted to Journal of Low Temperature Physics

The Design and Performance of Charged Particle Detector onboard the GECAM Mission [IMA]

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http://arxiv.org/abs/2112.05314


The Gravitational Wave highly energetic Electromagnetic Counterpart All-sky Monitor (GECAM) is dedicated to detecting gravitational wave gamma-ray bursts. It is capable of all-sky monitoring over and discovering gamma-ray bursts and new radiation phenomena. GECAM consists of two microsatellites, each equipped with 8 charged particle detectors (CPDs) and 25 gamma-ray detectors (GRDs). The CPD is used to measure charged particles in the space environment, monitor energy and flow intensity changes, and identify between gamma-ray bursts and space charged particle events in conjunction with GRD. CPD uses plastic scintillator as the sensitive material for detection, silicon photomultiplier (SiPM) array as the optically readable device, and the inlaid Am-241 radioactive source as the onboard calibration means. In this paper, we will present the working principle, physical design, functional implementation and preliminary performance test results of the CPD.

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Y. Xu, X. Sun, S. Yang, et. al.
Mon, 13 Dec 21
65/70

Comments: accepted to RDTM

The optical simulation model of the DarkSide-20k Veto detector [CL]

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http://arxiv.org/abs/2112.04990


DarkSide-20k is a rare-event search experiment aimed at finding signals of dark matter particles. It is a dual-phase detector that registers ionisation and scintillation signals originating from the particles interacting with the liquid argon detector medium. It is enclosed in a single-phase liquid argon neutron veto tank, equipped with Gd-loaded panels for capturing neutrons. Since vetoing and particle identification are carried out using the light signal, it is crucial to maximise the light yield. Light collection efficiency depends on optical properties of the detector and particularly for the veto detector, which has a photosensor coverage of the order of a per cent, the reflectivity of the walls has a big impact. To quantify the amount of collected light, a comprehensive Geant4 simulation is performed, which uses optical characterisation data. In this work, a detailed description of the optics model for the veto of the experiment will be discussed.

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C. Türkoğlu and S. Choudhary
Fri, 10 Dec 21
8/94

Comments: Proceedings of 17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021)

First results on SiSeRO (Single electron Sensitive Read Out) devices — a new X-ray detector for scientific instrumentation [IMA]

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http://arxiv.org/abs/2112.05033


We present an evaluation of a novel on-chip charge detector, called the Single electron Sensitive Read Out (SiSeRO), for charge-coupled device (CCD) image sensor applications. It uses a p-MOSFET transistor at the output stage with a depleted internal gate beneath the p-MOSFET. Charge transferred to the internal gate modulates the source-drain current of the transistor. We have developed a drain current readout module to characterize the detector. The prototype sensor achieves a charge/current conversion gain of 700 pA per electron, an equivalent noise charge (ENC) of 15 electrons (e-) root mean square (RMS), and a full width half maximum (FWHM) of 230 eV at 5.9 keV. In this paper, we discuss the SiSeRO working principle, the readout module developed at Stanford, and the first characterization test results of the SiSeRO prototypes. While at present only a proof-of-concept experiment, in the near future we plan to use next generation sensors with improved noise performance and an enhanced readout module. In particular, we are developing a readout module enabling Repetitive Non-Destructive Readout (RNDR) of the charge, which can in principle yield sub-electron ENC performance. With these developments, we eventually plan to build a matrix of SiSeRO amplifiers to develop an active pixel sensor with an on-chip ASIC-based readout system. Such a system, with fast readout speeds and sub-electron noise, could be effectively utilized in scientific applications requiring fast and low-noise spectro-imagers.

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T. Chattopadhyay, S. Herrmann, B. Burke, et. al.
Fri, 10 Dec 21
94/94

Comments: Submitted to Journal of Astronomical Telescopes, Instruments, and Systems (JATIS)

Stabilized laser systems at 1550nm wavelength for future gravitational wave detectors [CL]

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http://arxiv.org/abs/2112.03792


The continuous improvement of current gravitational wave detectors (GWDs) and the preparations for next generation GWDs place high demands on their stabilized laser sources. Some of the laser souces need to operate at laser wavelengths between 1.5um and 2.2um to support future detectors, based on cooled silicon test masses for thermal noise reduction. We present a detailed characterizations of different commercial low power seed laser sources and power amplifiers at the wavelength of 1550nm with regard to performance parameters needed in GWDs. A combination with the most complete set of actuators was arranged as a master-oscillator power amplifier (MOPA) and integrated into a stabilization environment. We demonstrate the operation of a pre-stabilized laser system (PSL) and characterize its performance. We present the results of this characterization that make this PSL to a highly relevant prototype for future GWDs as well as a low noise light source for other experiments in high precision metrology.

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F. Meylahn and B. Willke
Wed, 8 Dec 21
32/77

Comments: N/A

Digging into Axion Physics with (Baby)IAXO [IMA]

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http://arxiv.org/abs/2112.02286


Dark Matter searches have been ongoing for three decades; the lack of a positive discovery of the main candidate, the WIMP, after dedicated efforts, has put axions and axion-like-particles in the spotlight. The three main techniques employed to search for them complement each other well in covering a wide range in the parameter space defined by the axion decay constant and the axion mass. The International AXion Observatory (IAXO) is an international collaboration planning to build the fourth generation axion helioscope, with an unparalleled expected sensitivity and discovery potential. The distinguishing characteristic of IAXO is that it will feature an axion-specific magnet, with a large axion-sensitive cross-section, and will be equipped with x-ray focusing devices and detectors that have been developed for axion physics. In this paper, we review aspects that motivate IAXO and its prototype, BabyIAXO, in the axion and ALPs landscape. As part of this Special Issue, some emphasis is given on the Spanish participation in the project, of which CAPA is a strong promoter

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T. Dafni and J. Galan
Tue, 7 Dec 21
18/91

Comments: 21 pages, 5 figures. Submitted to Universe

Space applications of GAGG:Ce scintillators: a study of afterglow emission by proton irradiation [IMA]

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http://arxiv.org/abs/2112.02897


We discuss the results of a proton irradiation campaign of a GAGG:Ce (Cerium-doped Gadolinium Aluminium Gallium Garnet) scintillation crystal, carried out in the framework of the HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites — Technological and Scientific Pathfinder) mission. A scintillator sample was irradiated with 70 MeV protons, at levels equivalent to those expected in equatorial and sun-synchronous low-Earth orbits over orbital periods spanning 6 months to 10 years. The data we acquired are used to introduce an original model of GAGG:Ce afterglow emission. Results from this model are applied to the HERMES-TP/SP scenario, aiming at an upper-bound estimate of the detector performance degradation resulting from afterglow emission.

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G. Dilillo, N. Zampa, R. Campana, et. al.
Tue, 7 Dec 21
26/91

Comments: N/A

Low Noise Frequency Domain Multiplexing of TES Bolometers using Sub-kelvin SQUIDs [CL]

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http://arxiv.org/abs/2112.02425


Digital Frequency-Domain Multiplexing (DfMux) is a technique that uses MHz superconducting resonators and Superconducting Quantum Interference Device (SQUID) arrays to read out sets of Transition Edge Sensors. DfMux has been used by several Cosmic Microwave Background experiments, including most recently POLARBEAR-2 and SPT-3G with multiplexing factors as high as 68, and is the baseline readout technology for the planned satellite mission LiteBIRD. Here, we present recent work focused on improving DfMux readout noise, reducing parasitic impedance, and improving sensor operation. We have achieved a substantial reduction in stray impedance by integrating the sensors, resonators, and SQUID array onto a single carrier board operated at 250 mK. This also drastically simplifies the packaging of the cryogenic components and leads to better-controlled crosstalk. We demonstrate a low readout noise level of 8.6 pA/Hz$^{-1/2}$, which was made possible by operating the SQUID array at a reduced temperature and with a low dynamic impedance. This is a factor of two improvement compared to the achieved readout noise level in currently operating Cosmic Microwave Background experiments using DfMux and represents a critical step toward maturation of the technology for the next generation of instruments.

Read this paper on arXiv…

T. Elleflot, A. Suzuki, K. Arnold, et. al.
Tue, 7 Dec 21
45/91

Comments: N/A

Neutral bremsstrahlung electroluminescence in noble liquids [CL]

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http://arxiv.org/abs/2112.01737


Proportional electroluminescence (EL) is the physical effect used in two-phase dark matter detectors, to optically record in the gas phase the ionization signal produced by particle scattering in the liquid phase. In our previous works the presence of a new EL mechanism in noble gases, namely that of neutral bremsstrahlung (NBrS), was demonstrated both theoretically and experimentally, in addition to the ordinary EL mechanism due to excimer emission. In this work we show that the similar theoretical approach can apply to noble liquids, namely to liquid helium, neon, argon, krypton and xenon. In particular, the photon yields and spectra for NBrS EL in noble liquids have for the first time been calculated, using the electron energy and transport parameters obtained in the framework of Cohen-Lekner and Atrazhev theory. The relevance of the results obtained to the development of noble liquid detectors for dark matter searches and neutrino experiments is discussed.

Read this paper on arXiv…

E. Borisova and A. Buzulutskov
Mon, 6 Dec 21
9/61

Comments: 7 pages, 6 figures

Optimal Sensor Fusion Method for Active Vibration Isolation Systems in Ground-based Gravitational-wave Detectors [CL]

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http://arxiv.org/abs/2111.14355


Sensor fusion is a technique used to combine sensors with different noise characteristics into a super sensor that has superior noise performance. To achieve sensor fusion, complementary filters are used in current gravitational-wave detectors to combine relative displacement sensors and inertial sensors for active seismic isolation. Complementary filters are a set of digital filters, which have transfer functions that are summed to unity. Currently, complementary filters are shaped and tuned manually rather than optimized, which can be suboptimal and hard to reproduce for future detectors. In this paper, an optimization-based method called $\mathcal{H}_\infty$ synthesis is proposed for synthesizing optimal complementary filters according to the sensor noises themselves. The complementary filter design problem is converted into an optimization problem that seeks minimization of an objective function equivalent to the maximum difference between the super sensor noise and the lower bound in logarithmic scale. The method is exemplified by synthesizing complementary filters for sensor fusion of 1) a relative displacement sensor and an inertial sensor, 2) a relative displacement sensor coupled with seismic noise and an inertial sensor, and 3) hypothetical displacement sensor and inertial sensor, which have slightly different noise characteristics compared to the typical ones. In all cases, the method produces complementary filters that suppress the super sensor noise equally close to the lower bound at all frequencies in logarithmic scale. The synthesized filters contain features that better suppress the sensor noises compared to the pre-designed complementary filters. Overall, the proposed method allows the synthesis of optimal complementary filters according to the sensor noises themselves and is a better and versatile method for solving sensor fusion problems.

Read this paper on arXiv…

T. Tsang, T. Li, T. Dehaeze, et. al.
Tue, 30 Nov 21
59/105

Comments: N/A

Broadband solenoidal haloscope for terahertz axion detection [CL]

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http://arxiv.org/abs/2111.12103


We introduce the Broadband Reflector Experiment for Axion Detection (BREAD) conceptual design and science program. This haloscope plans to search for bosonic dark matter across the [10$^{-3}$, 1] eV ([0.24, 240] THz) mass range. BREAD proposes a cylindrical metal barrel to convert dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. This unique geometry enables enclosure in standard cryostats and high-field solenoids, overcoming limitations of current dish antennas. A pilot 0.7 m$^{2}$ barrel experiment planned at Fermilab is projected to surpass existing dark photon coupling constraints by over a decade with one-day runtime. Axion sensitivity requires $<10^{-20}$ W/$\sqrt{\textrm{Hz}}$ sensor noise equivalent power with a 10 T solenoid and 10 m$^{2}$ barrel. We project BREAD sensitivity for various sensor technologies and discuss future prospects.

Read this paper on arXiv…

J. Liu, K. Dona, G. Hoshino, et. al.
Thu, 25 Nov 21
4/60

Comments: 5 pages, 2 figures + references and appendices

Thermal crosstalk of X-ray transition-edge sensor micro-calorimeters under frequency domain multiplexing readout [IMA]

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http://arxiv.org/abs/2111.12445


We have measured and characterized the thermal crosstalk in two different arrays of transition-edge sensor (TES) X-ray micro-calorimeters with frequency-domain multiplexing (FDM) readout. The TES arrays are fabricated at SRON and are a 8$\times$8 and a 32$\times$32 “kilo-pixel” uniform array. The amount of crosstalk is evaluated as the ratio between the averaged crosstalk signal and the X-ray pulse amplitudes. The crosstalk ratios (CR) for our detectors are compliant with the requirements for future X-ray space missions, such as Athena X-IFU (CR$< 10^{-3}$ for first-neighbour pixels): we measured a nearest-neighbour thermal crosstalk ratio at a level of $10^{-4}$, with a highest crosstalk ratio of $4\times 10^{-4}$ for the kilo-pixel array (worst case, center of array) and $1\times 10^{-4}$ for the 8$\times$8 array, with a margin of improvement achievable by optimizing the Cu metallization and the width of the Si supporting structures (muntins) in the backside of the TES array chip. Based on the measured crosstalk ratios, we have estimated the impact on the spectral resolution by means of noise equivalent power (NEP) considerations and a Monte Carlo simulation, finding an average degradation in quadrature of less than 40~meV, compliant with the < 0.2~eV requirement for Athena X-IFU.

Read this paper on arXiv…

D. Vaccaro, H. Akamatsu, M. Bruijn, et. al.
Thu, 25 Nov 21
14/60

Comments: N/A

A Compact High-Resolution Muon Spectrometer Using Multi-Layer Gas Cherenkov Radiators [CL]

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http://arxiv.org/abs/2111.12512


In both particle physics and cosmic ray muon applications, a high-resolution muon momentum measurement capability plays a significant role not only in providing valuable information on the properties of subatomic particles but also in improving the utilizability of muons. Currently, muon momentum is estimated by reconstructing the muon path using a strong magnetic field and muon trackers. Alternatively, time-of-flight or multiple Coulomb scattering techniques are less frequently applied, especially when there is a need to avoid using a magnetic field. However, the measurement resolution is much lower than that of magnetic spectrometers, approximately 20% in the muon momentum range of 0.5 to 4.5 GeV/c whereas it is nearly 10% or less when using magnets and trackers. Here, we propose a different paradigm to estimate muon momentum that utilizes multi-layer pressurized gas Cherenkov radiators. Using the fact that the gas refractive index varies with pressure and temperature, we can optimize the muon Cherenkov threshold momentum for which a muon signal will be detected. By analyzing the optical signals from Cherenkov radiation, we show that the actual muon momentum can be estimated with a minimum resolution of +-0.05 GeV/c for a large number of radiators over the range of 0.1 to 10.0 GeV/c. The results also show that our spectrometer correctly classifies the muon momentum (~87% classification rate) in the momentum range of 0.1 to 10.0 GeV/c. We anticipate our new spectrometer will to provide an alternative substitute for the bulky magnets without degrading measurement resolution. Furthermore, we expect it will significantly improve the quality of imaging or reduce the scanning time in cosmic muon applications by being incorporated with existing instruments.

Read this paper on arXiv…

J. Bae and S. Chatzidakis
Thu, 25 Nov 21
35/60

Comments: N/A

Broadband solenoidal haloscope for terahertz axion detection [CL]

Posted on by

http://arxiv.org/abs/2111.12103


We introduce the Broadband Reflector Experiment for Axion Detection (BREAD) conceptual design and science program. This haloscope plans to search for bosonic dark matter across the [10$^{-3}$, 1] eV ([0.24, 240] THz) mass range. BREAD proposes a cylindrical metal barrel to convert dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. This unique geometry enables enclosure in standard cryostats and high-field solenoids, overcoming limitations of current dish antennas. A pilot 0.7 m$^{2}$ barrel experiment planned at Fermilab is projected to surpass existing dark photon coupling constraints by over a decade with one-day runtime. Axion sensitivity requires $<10^{-20}$ W/$\sqrt{\textrm{Hz}}$ sensor noise equivalent power with a 10 T solenoid and 10 m$^{2}$ barrel. We project BREAD sensitivity for various sensor technologies and discuss future prospects.

Read this paper on arXiv…

J. Liu, K. Dona, G. Hoshino, et. al.
Thu, 25 Nov 21
4/60

Comments: 5 pages, 2 figures + references and appendices

Thermal crosstalk of X-ray transition-edge sensor micro-calorimeters under frequency domain multiplexing readout [IMA]

Posted on by

http://arxiv.org/abs/2111.12445


We have measured and characterized the thermal crosstalk in two different arrays of transition-edge sensor (TES) X-ray micro-calorimeters with frequency-domain multiplexing (FDM) readout. The TES arrays are fabricated at SRON and are a 8$\times$8 and a 32$\times$32 “kilo-pixel” uniform array. The amount of crosstalk is evaluated as the ratio between the averaged crosstalk signal and the X-ray pulse amplitudes. The crosstalk ratios (CR) for our detectors are compliant with the requirements for future X-ray space missions, such as Athena X-IFU (CR$< 10^{-3}$ for first-neighbour pixels): we measured a nearest-neighbour thermal crosstalk ratio at a level of $10^{-4}$, with a highest crosstalk ratio of $4\times 10^{-4}$ for the kilo-pixel array (worst case, center of array) and $1\times 10^{-4}$ for the 8$\times$8 array, with a margin of improvement achievable by optimizing the Cu metallization and the width of the Si supporting structures (muntins) in the backside of the TES array chip. Based on the measured crosstalk ratios, we have estimated the impact on the spectral resolution by means of noise equivalent power (NEP) considerations and a Monte Carlo simulation, finding an average degradation in quadrature of less than 40~meV, compliant with the < 0.2~eV requirement for Athena X-IFU.

Read this paper on arXiv…

D. Vaccaro, H. Akamatsu, M. Bruijn, et. al.
Thu, 25 Nov 21
9/60

Comments: N/A

A Compact High-Resolution Muon Spectrometer Using Multi-Layer Gas Cherenkov Radiators [CL]

Posted on by

http://arxiv.org/abs/2111.12512


In both particle physics and cosmic ray muon applications, a high-resolution muon momentum measurement capability plays a significant role not only in providing valuable information on the properties of subatomic particles but also in improving the utilizability of muons. Currently, muon momentum is estimated by reconstructing the muon path using a strong magnetic field and muon trackers. Alternatively, time-of-flight or multiple Coulomb scattering techniques are less frequently applied, especially when there is a need to avoid using a magnetic field. However, the measurement resolution is much lower than that of magnetic spectrometers, approximately 20% in the muon momentum range of 0.5 to 4.5 GeV/c whereas it is nearly 10% or less when using magnets and trackers. Here, we propose a different paradigm to estimate muon momentum that utilizes multi-layer pressurized gas Cherenkov radiators. Using the fact that the gas refractive index varies with pressure and temperature, we can optimize the muon Cherenkov threshold momentum for which a muon signal will be detected. By analyzing the optical signals from Cherenkov radiation, we show that the actual muon momentum can be estimated with a minimum resolution of +-0.05 GeV/c for a large number of radiators over the range of 0.1 to 10.0 GeV/c. The results also show that our spectrometer correctly classifies the muon momentum (~87% classification rate) in the momentum range of 0.1 to 10.0 GeV/c. We anticipate our new spectrometer will to provide an alternative substitute for the bulky magnets without degrading measurement resolution. Furthermore, we expect it will significantly improve the quality of imaging or reduce the scanning time in cosmic muon applications by being incorporated with existing instruments.

Read this paper on arXiv…

J. Bae and S. Chatzidakis
Thu, 25 Nov 21
40/60

Comments: N/A

Performance of a focal plane detector for soft X-ray imaging spectroscopy based on back-illuminated sCMOS [CL]

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http://arxiv.org/abs/2111.11610


Spectroscopy focusing array (SFA) and Polarimetry focusing array (PFA) are the two major payloads of enhanced X-ray Timing and Polarimetry mission (eXTP). Nested Wolter-\RNum{1} X-ray mirror module is implemented in SFA and PFA to achive high effective area. When evaluating the properties of the mirror module, the alignment of the optical axis of the X-ray mirror module and a quasi-parallel X-ray beam is a prerequisite to ensure the accuracy of the results. Hence, to assist the alignment of the X-ray mirror module, an X-ray focal plane detector is designed based on the back-illuminated scientific Complementary Metal-Oxide-Semiconductor Transistor (sCMOS) sensor GSENSE6060BSI, one of the largest detection areas, is produced by \textit{Gpixel Inc}. Then the characteristics of readout noise, dark current, and split-pixel event properties of the detector are studied with the self-developed multi-target fluorescence X-ray source in a 100 m long X-ray test facility. The energy calibration is carried out with the single-pixel event and the energy non-linearity of the detector is also obtained. Eventually, the simulation of the eXTP mirror module based on the optical model is conducted and the alignment test of the Wolter-\RNum{1} X-ray mirror module designed for \textit{EP/FXT} (Einstein Probe/Follow-up X-ray Telescope) with “Burkert test” method is shown.

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C. Chen, Y. Wang, Y. Xu, et. al.
Wed, 24 Nov 21
31/61

Comments: 27 pages, 16 pages, submitted to NIM-A

The Simons Observatory: Magnetic Shielding Measurements for the Universal Multiplexing Module [IMA]

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http://arxiv.org/abs/2111.11495


The Simons Observatory (SO) includes four telescopes that will measure the temperature and polarization of the cosmic microwave background using over 60,000 highly sensitive transition-edge bolometers (TES). These multichroic TES bolometers are read out by a microwave RF SQUID multiplexing system with a multiplexing factor of 910. Given that both TESes and SQUIDs are susceptible to magnetic field pickup and that it is hard to predict how they will respond to such fields, it is important to characterize the magnetic response of these systems empirically. This information can then be used to limit spurious signals by informing magnetic shielding designs for the detectors and readout. This paper focuses on measurements of magnetic pickup with different magnetic shielding configurations for the SO universal multiplexing module (UMM), which contains the SQUIDs, associated resonators, and TES bias circuit. The magnetic pickup of a prototype UMM was tested under three shielding configurations: no shielding (copper packaging), aluminum packaging for the UMM, and a tin/lead-plated shield surrounding the entire dilution refrigerator 100 mK cold stage. The measurements show that the aluminum packaging outperforms the copper packaging by a shielding factor of 8-10, and adding the tin/lead-plated 1K shield further increases the relative shielding factor in the aluminum configuration by 1-2 orders of magnitude.

Read this paper on arXiv…

Z. Huber, Y. Li, E. Vavagiakis, et. al.
Wed, 24 Nov 21
59/61

Comments: 7 pages, 4 figure, conference proceedings submitted to the Journal of Low Temperature Physics

Simons Observatory Focal-Plane Module: In-lab Testing and Characterization Program [IMA]

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http://arxiv.org/abs/2111.11301


The Simons Observatory (SO) is a ground-based cosmic microwave background instrument to be sited in the Atacama Desert in Chile. SO will deploy 60,000 transition-edge sensor bolometers in 49 separate focal-plane modules across a suite of four telescopes covering three dichroic bands termed low frequency (LF), mid frequency (MF) and ultra-high frequency (UHF). Each MF and UHF focal-plane module packages 1720 optical detectors and corresponding 100 mK microwave SQUID multiplexing readout components. In this paper we describe the testing program we have developed for high-throughput validation of the modules after they are assembled. The validation requires measurements of the yield, saturation powers, time constants, noise properties and optical efficiencies. Additional measurements will be performed for further characterizations as needed. We describe the methods developed and demonstrate preliminary results from initial testing of prototype modules.

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Y. Wang, K. Zheng, Z. Atkins, et. al.
Tue, 23 Nov 21
11/84

Comments: N/A

Quenching Factor consistency across several NaI(Tl) crystals [IMA]

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http://arxiv.org/abs/2111.09590


Testing the DAMA/LIBRA annual modulation result independently of dark matter particle and halo models has been a challenge for twenty years. Using the same target material, NaI(Tl), is required and presently two experiments, ANAIS-112 and COSINE-100, are running for such a goal. A precise knowledge of the detector response to nuclear recoils is mandatory because this is the most likely channel to find the dark matter signal. The light produced by nuclear recoils is quenched with respect to that produced by electrons by a factor that has to be measured experimentally. However, current quenching factor measurements in NaI(Tl) crystals disagree within the energy region of interest for dark matter searches. To disentangle whether this discrepancy is due to intrinsic differences in the light response among different NaI(Tl) crystals, or has its origin in unaccounted for systematic effects will be key in the comparison among the different experiments. We present measurements of the quenching factors for five small NaI(Tl) crystals performed in the same experimental setup to control systematics. Quenching factor results are compatible between crystals and no clear dependence with energy is observed from 10 to 80 keVnr.

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D. Cintas, P. An, C. Awe, et. al.
Fri, 19 Nov 21
53/67

Comments: Proceeding of the TAUP 2021 Conference

Three-year annual modulation search with COSINE-100 [CL]

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http://arxiv.org/abs/2111.08863


COSINE-100 is a direct detection dark matter experiment that aims to test DAMA/LIBRA’s claim of dark matter discovery by searching for a dark matter-induced annual modulation signal with NaI(Tl) detectors. We present new constraints on the annual modulation signal from a dataset with a 2.82 yr livetime utilizing an active mass of 61.3 kg, for a total exposure of 173 kg$\cdot$yr. This new result features an improved event selection that allows for both lowering the energy threshold to 1 keV and a more precise time-dependent background model. In the 1-6 keV and 2-6 keV energy intervals, we observe best-fit values for the modulation amplitude of 0.0067$\pm$0.0042 and 0.0050$\pm$0.0047 counts/(day$\cdot$kg$\cdot$keV), respectively, with a phase fixed at 152.5 days.

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C. Collaboration, G. Adhikari, E. Souza, et. al.
Thu, 18 Nov 21
7/92

Comments: 9 pages, 8 figures

Proposed large scale monolithic fused silica mirror suspension for 3rd generation gravitational wave detectors [IMA]

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http://arxiv.org/abs/2111.09119


Thermal noise from the suspension fibres used in the mirror pendulums in current gravitational wave detectors is a critical noise source. Future detectors will require improved suspension performance with the specific ability to suspend much heavier masses to reduce radiation pressure noise, whilst retaining good thermal noise performance. In this letter, we propose and experimentally demonstrate a design for a large-scale fused silica suspension, demonstrating its suitability for holding an increased mass of 160 kg. We demonstrate the concepts for improving thermal noise via longer suspension fibres supporting a higher static stress. We present a full thermal noise analysis of our prototype, meeting requirements for conceptual 3rd generation detector designs such as the high frequency interferometer of the Einstein Telescope (ET-HF), and closely approaching that required for Cosmic Explorer (CE).

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A. Cumming, R. Jones, G. Hammond, et. al.
Thu, 18 Nov 21
66/92

Comments: 7 pages, 5 figures

Total power horn-coupled 150 GHz LEKID array for space applications [IMA]

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http://arxiv.org/abs/2111.08388


We have developed two arrays of lumped element kinetic inductance detectors working in the D-band, and optimised for the low radiative background conditions of a satellite mission aiming at precision measurements of the Cosmic Microwave Background (CMB). The first detector array is sensitive to the total power of the incoming radiation to which is coupled via single-mode waveguides and corrugated feed-horns, while the second is sensitive to the polarisation of the radiation thanks to orthomode transducers. Here, we focus on the total power detector array, which is suitable, for instance, for precision measurements of unpolarised spectral distortions of the CMB, where detecting both polarisations provides a sensitivity advantage. We describe the optimisation of the array design, fabrication and packaging, the dark and optical characterisation, and the performance of the black-body calibrator used for the optical tests. We show that almost all the detectors of the array are photon-noise limited under the radiative background of a 3.6 K black-body. This result, combined with the weak sensitivity to cosmic rays hits demonstrated with the OLIMPO flight, validates the idea of using lumped elements kinetic inductance detectors for precision, space-based CMB missions.

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A. Paiella, A. Coppolecchia, P. Bernardis, et. al.
Wed, 17 Nov 21
3/64

Comments: To be submitted to JCAP

Near ground horizontal high resolution $C_n^2$ profiling from Shack-Hartmann slope and scintillation data [IMA]

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http://arxiv.org/abs/2111.08003


CO-SLIDAR is a very promising technique for the metrology of near ground $C_n^2$ profiles. It exploits both phase and scintillation measurements obtained with a dedicated wavefront sensor and allows profiling on the full line of sight between pupil and sources. This technique is applied to an associated instrument based on a mid-IR Shack-Hartmann wavefront sensor, coupled to a 0.35 m telescope, which observes two cooperative sources. This paper presents the first comprehensive description of the CO-SLIDAR method in the context of near ground optical turbulence metrology. It includes the presentation of the physics principles underlying the measurements, of our unsupervised $C_n^2$ profile reconstruction strategy together with the error bar estimation on the reconstructed values. The application to data acquired in a heterogeneous rural landscape during an experimental campaign in Lannemezan (France) demonstrates the ability to obtain profiles with a sampling pitch of about 220 m over a 2.7 km line of sight. The retrieved $C_n^2$ profiles are presented and their variability in space and time is discussed.

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C. Sauvage, C. Robert, L. Mugnier, et. al.
Wed, 17 Nov 21
17/64

Comments: N/A

Operation of an archaeological lead PbWO$_4$ crystal to search for neutrinos from astrophysical sources with a Transition Edge Sensor [CL]

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http://arxiv.org/abs/2111.07638


The experimental detection of the CE$\nu$NS allows the investigation of neutrinos and neutrino sources with all-flavor sensitivity. Given its large content in neutrons and stability, Pb is a very appealing choice as target element. The presence of the radioisotope $^{210}$Pb (T$_{1/2}\sim$22 yrs) makes natural Pb unsuitable for low-background, low-energy event searches. This limitation can be overcome employing Pb of archaeological origin, where several half-lives of $^{210}$Pb have gone by. We present results of a cryogenic measurement of a 15g PbWO$_4$ crystal, grown with archaeological Pb (older than $\sim$2000 yrs) that achieved a sub-keV nuclear recoil detection threshold. A ton-scale experiment employing such material, with a detection threshold for nuclear recoils of just 1 keV would probe the entire Milky Way for SuperNovae, with equal sensitivity for all neutrino flavors, allowing the study of the core of such exceptional events.

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N. Iachellini, L. Pattavina, A. Abdelhameed, et. al.
Tue, 16 Nov 21
42/97

Comments: ltd proceeding

Micro-X Sounding Rocket Payload Re-flight Progress [IMA]

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http://arxiv.org/abs/2111.06952


Micro-X is an X-ray sounding rocket payload that had its first flight on July 22, 2018. The goals of the first flight were to operate a transition edge sensor (TES) X-ray microcalorimeter array in space and take a high-resolution spectrum of the Cassiopeia A supernova remnant. The first flight was considered a partial success. The array and its time-division multiplexing readout system were successfully operated in space, but due to a failure in the attitude control system, no time on-target was acquired. A re-flight has been scheduled for summer 2022. Since the first flight, modifications have been made to the detector systems to improve noise and reduce the susceptibility to magnetic fields. The three-stage SQUID circuit, NIST MUX06a, has been replaced by a two-stage SQUID circuit, NIST MUX18b. The initial laboratory results for the new detector system will be presented in this paper.

Read this paper on arXiv…

J. Adams, S. Bandler, N. Bastidon, et. al.
Tue, 16 Nov 21
54/97

Comments: LTD proceedings, 6 pages, 3 figures, 1 table

High-accuracy numerical models of Brownian thermal noise in thin mirror coatings [IMA]

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http://arxiv.org/abs/2111.06893


Brownian coating thermal noise in detector test masses is limiting the sensitivity of current gravitational-wave detectors on Earth. Therefore, accurate numerical models can inform the ongoing effort to minimize Brownian coating thermal noise in current and future gravitational-wave detectors. Such numerical models typically require significant computational resources and time, and often involve closed-source commercial codes. In contrast, open-source codes give complete visibility and control of the simulated physics and enable direct assessment of the numerical accuracy. In this article, we use the open-source SpECTRE numerical-relativity code and adopt a novel discontinuous Galerkin numerical method to model Brownian coating thermal noise. We demonstrate that SpECTRE achieves significantly higher accuracy than a previous approach at a fraction of the computational cost. Furthermore, we numerically model Brownian coating thermal noise in multiple sub-wavelength crystalline coating layers for the first time. Our new numerical method has the potential to enable fast exploration of realistic mirror configurations, and hence to guide the search for optimal mirror geometries, beam shapes and coating materials for gravitational-wave detectors.

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N. Fischer, S. Rodriguez, T. Wlodarczyk, et. al.
Tue, 16 Nov 21
78/97

Comments: 9 pages, 5 figures. Results are reproducible with the ancillary input files

Statistical investigation of the large-area Si(Li) detectors mass-produced for the GAPS experiment [CL]

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http://arxiv.org/abs/2111.06100


The lithium-drifted silicon (Si(Li)) detector developed for the General Antiparticle Spectrometer (GAPS) experiment features a thick (~2.2 mm) sensitive layer, large (10 cm) diameter, and excellent energy resolution (~4 keV for 20-100 keV X-rays) at a relatively high operating temperature (approximately -40C). Mass production of GAPS Si(Li) detectors has been performed to construct a large-volume silicon tracker for GAPS. We achieved the first success of the mass production of large-area Si(Li) detectors with a high (~90%) yield rate. Valuable datasets related to detector fabrication, such as detector performance and manufacturing parameters, were recorded and collected during the mass production. This study analyzes the datasets using statistical methods with the aim of comprehensively examining the mass production and to gain valuable insight into the fabrication method. Sufficient uniformities of the performance parameters (leakage current and capacitance) between detectors and strips are found, demonstrating high-quality and stable mass production. We also search for correlations between detector performance and manufacturing parameters by using data-mining techniques. Conventional multivariate analysis (multiple regression analysis) and machine-learning techniques (regression tree analysis) are complementarily used, and it is found that the Li-drift process makes a significant contribution to the performance parameters of the finished detectors. Detailed investigation of the drift process is performed using environmental data, and physical interpretations are presented. Our results provide valuable insight into the fabrication methods for this kind of large-area Si(Li) detector, and encourages future projects that require large-volume silicon trackers.

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M. Kozai, K. Tokunaga, H. Fuke, et. al.
Fri, 12 Nov 21
33/53

Comments: 49 pages, 18 figures, submitted to Nuclear Instruments and Methods in Physics Research Section A

Large Inverse Transient Phase Response of Titanium-nitride-based Microwave Kinetic Inductance Detectors [IMA]

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http://arxiv.org/abs/2111.05189


Following optical pulses ($\lambda=405~\text{nm}$) on titanium nitride (TiN) Microwave Kinetic Inductance Detectors (MKIDs) cooled down at temperatures $T \le T_c / 20$ ($T_c \simeq 4.6~\text{K}$), we observe a large phase-response highlighting two different modes simultaneously that are nevertheless related. The first corresponds to the well-known transition of cooper-pair breaking into quasi-particles which produces a known phase response. This is immediately followed by a large inverse response lasting several hundreds of microseconds to several milliseconds depending on the temperature. We propose to model this inverse pulse as the thermal perturbation of the superconductor and interaction with two level system (TLS) that reduces the dielectric constant which in turns modify the capacitance and therefore the resonance frequency. The ratio of the TLS responding to the illumination is on the order of that of the area of the inductor to the whole resonator

Read this paper on arXiv…

J. Hu, F. Boussaha, J. Martin, et. al.
Wed, 10 Nov 21
19/63

Comments: Accepted by Applied Physics Letters

The Simulation and Design of an On-Chip Superconducting Millimetre Filter-Bank Spectrometer [IMA]

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http://arxiv.org/abs/2111.04632


Superconducting on-chip filter-banks provide a scalable, space saving solution to create imaging spectrometers at millimetre and sub-millimetre wavelengths. We present an easy to realise, lithographed superconducting filter design with a high tolerance to fabrication error. Using a capacitively coupled $\lambda/2$ microstrip resonator to define a narrow ($\lambda/\Delta\lambda = 300$) spectral pass band, the filtered output of a given spectrometer channel directly connects to a Lumped Element Kinetic Inductance Detector (LEKID). We show the tolerance analysis of our design, demonstrating $<11\%$ change in filter quality factor to any one realistic fabrication errors and a full filter-bank efficiency forecast to be 60\% after accounting for fabrication errors and dielectric loss tangent.

Read this paper on arXiv…

G. Robson, A. Anderson, P. Barry, et. al.
Tue, 9 Nov 21
68/102

Comments: 8 pages, 5 figures. Pre-print for proceedings for the Journal of Low Temperature Physics, 19th Low Temperature Detectors Conference (LTD19)

Design of SPT-SLIM focal plane; a spectroscopic imaging array for the South Pole Telescope [IMA]

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http://arxiv.org/abs/2111.04633


The Summertime Line Intensity Mapper (SLIM) is a mm-wave line-intensity mapping (mm-LIM) experiment for the South Pole Telescope (SPT). The goal of SPT-SLIM is to serve as a technical and scientific pathfinder for the demonstration of the suitability and in-field performance of multi-pixel superconducting filterbank spectrometers for future mm-LIM experiments. Scheduled to deploy in the 2023-24 austral summer, the SPT-SLIM focal plane will include 18 dual-polarization pixels, each coupled to an $R = \lambda/\Delta\lambda$ = 300 thin- film microstrip filterbank spectrometer that spans the 2 mm atmospheric window (120-180 GHz). Each individual spectral channel feeds a microstrip-coupled lumped-element kinetic inductance detector, which provides the highly multiplexed readout for the 10k detectors needed for SPT-SLIM. Here we present an overview of the preliminary design of key aspects of the SPT-SLIM the focal plane array, a description of the detector architecture and predicted performance, and initial test results that will be used to inform the final design of the SPT- SLIM spectrometer array.

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P. Barry, A. Anderson, B. Benson, et. al.
Tue, 9 Nov 21
80/102

Comments: Submitted to special issue of JLTP (proceedings of LTD19)

Status of the DEAP-3600 experiment [CL]

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http://arxiv.org/abs/2111.03161


DEAP-3600 is a single-phase liquid argon (LAr) dark matter detector, located 2 km underground at SNOLAB in Sudbury, Canada, which started taking data in 2016. The detector is sensitive to nuclear recoils induced by scattering of dark matter particles, which would cause emission of prompt scintillation light. DEAP-3600 demonstrated excellent performance, holds the leading WIMP exclusion among LAr detectors, and published several physics results. The WIMP sensitivity of the detector is currently limited by backgrounds induced by alpha activity at the LAr inlet, in a shadowed region of detector. The ongoing hardware upgrade aims at fixing that limitation and, in consequence, at reaching the full WIMP sensitivity. This paper summarizes the latest results from DEAP-3600 and details of the upgrade.

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M. Kuźniak
Mon, 8 Nov 21
8/69

Comments: Proceedings of 17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021)

Nonlinear noise regression in gravitational-wave detectors with convolutional neural networks [IMA]

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http://arxiv.org/abs/2111.03295


Currently, the sub-60 Hz sensitivity of gravitational-wave (GW) detectors like Advanced LIGO is limited by the control noises from auxiliary degrees of freedom, which nonlinearly couple to the main GW readout. One particularly promising way to tackle this contamination is to perform nonlinear noise mitigation using machine-learning-based convolutional neural networks (CNNs), which we examine in detail in this study. As in many cases the noise coupling is bilinear and can be viewed as a few fast channels’ outputs modulated by some slow channels, we show that we can utilize this knowledge of the physical system and adopt an explicit “slow$\times$fast” structure in the design of the CNN to enhance its performance of noise subtraction. We then examine the requirement in the signal-to-noise ratio (SNR) in both the target channel (i.e., the main GW readout) and in the auxiliary sensors in order to reduce the noise by at least a factor of a few. In the case of limited SNR in the target channel, we further demonstrate that the CNN can still reach a good performance if we adopt curriculum learning techniques, which in reality can be achieved by combining data from quiet times and those from periods with active noise injections.

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H. Yu and R. Adhikari
Mon, 8 Nov 21
64/69

Comments: 20 pages, 7 figures; contribution to “Efficient AI in Particle Physics and Astrophysics” in Frontiers in Artificial Intelligence and Frontiers in Big Data

The search for Light Dark Matter with NEWS-G [CL]

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http://arxiv.org/abs/2111.02796


The NEWS-G direct dark matter search experiment uses spherical proportional counters (SPC) with light noble gases to explore low WIMP masses. The first results obtained with an SPC prototype operated with Ne gas at the Laboratoire Souterrain de Modane (LSM) have already set competitive results for low-mass WIMPs. The forthcoming next phase of the experiment consists of a large 140 cm diameter SPC installed at SNOLAB with a new sensor design, with improved detector performance and data quality. Before its installation at SNOLAB, the detector was commissioned with pure methane gas at the LSM, with a temporary water shield, offering a hydrogen-rich target and reduced backgrounds. After giving an overview of the improvements of the detector, preliminary results of this campaign will be discussed, including UV laser and Ar-37 calibration data.

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D. Durnford and M. Piro
Fri, 5 Nov 21
29/72

Comments: 5 pages, 5 figures

Identifying drivers of energy resolution variation in multi-KID phonon-mediated detectors [CL]

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http://arxiv.org/abs/2111.02587


Phonon-mediated particle detectors employing Kinetic Inductance Detectors (KIDs) on Silicon substrates have demonstrated both O(10) eV energy resolution and mm position resolution, making them strong candidates for instrumenting next generation rare-event experiments such as in looking for dark matter or in neutrino measurements. Previous work has demonstrated the performance of an 80-KID array on a Si wafer, however current energy resolution measurements show a 25x difference between otherwise identical KIDs on the same wafer – between 5 to 125 eV on energy absorbed by the KID. Here, we use a first principles approach and attempt to identify the drivers behind the resolution variation. In particular, we analyze a subset of 8 KIDs using the unique approach of pulsing neighboring KIDs to generate signals in the target. We tentatively identify differences in quality factor terms as the likely culprit for the observed variation.

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K. Ramanathan, T. Aralis, R. Thakur, et. al.
Fri, 5 Nov 21
60/72

Comments: 7 pages, 6 figures, Proceedings for the 19th International Workshop on Low Temperature Detectors (LTD19)

Demonstration of MHz frequency domain multiplexing readout of 37 transition edge sensors for high-resolution x-ray imaging spectrometers [CL]

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http://arxiv.org/abs/2111.01797


We report on the development and demonstration of a MHz frequency domain multiplexing (FDM) technology to read out arrays of cryogenic transition edge sensor (TES) X-ray microcalorimeters. In our FDM scheme, TESs are AC-biased at different resonant frequencies in the low MHz range through an array of high-$Q$ LC resonators. The current signals of all TESs are summed at superconducting quantum interference devices (SQUIDs). We have demonstrated multiplexing for a readout of 31 pixels using room temperature electronics, high-$Q$ LC filters and TES arrays developed at SRON, and SQUID arrays from VTT. We repeated this on a second setup with 37 pixels. The summed X-ray spectral resolutions $@$ 5.9 keV are $\Delta E_{\rm 31 pix ~MUX}=2.14\pm0.03$ eV and $\Delta E_{\rm 37 pix ~MUX}=2.23\pm0.03$ eV. The demonstrated results are comparable with other multiplexing approaches. There is potential to further improve the spectral resolution and to increase the number of multiplexed TESs, and to open up applications for TES X-ray microcalorimeters.

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H. Akamatsu, D. Vaccaro, L. Gottardi, et. al.
Thu, 4 Nov 21
3/73

Comments: 6 pages, 3 figures, accepted for publication on Applied physics letters

A Portuguese radar tracking sensor for Space Debris monitoring [IMA]

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http://arxiv.org/abs/2111.02232


The increase in space debris is a threat to space assets, space based-operations and led to a common effort to develop programs for dealing with this increase. As part of the Portuguese Space Surveillance and Tracking (SST) project, led by the Portuguese Ministry of Defense (MoD), the Instituto de Telecomunica\c{c}\~oes (IT) is developing rAdio TeLescope pAmpilhosa Serra (ATLAS), a new monostatic radar tracking sensor located at the Pampilhosa da Serra Space Observatory (ErPoB), Portugal. The system operates at 5.56 GHz and aims to provide information on objects in low earth orbit (LEO) orbits, with cross sections above 10 cm2 at 1000 km. ErPoB houses all the necessary equipment to connect to the research and development team in IT-Aveiro and to the European Union Space Surveillance and Tracking (EU-SST) network through the Portuguese SST-PT network and operation center. The ATLAS system features digital waveform synthesis, power amplifiers using Gallium Nitride (GaN) technology, fully digital signal processing and a highly modular architecture that follows an Open Systems (OS) philosophy and uses Commercial-Off-The-Shelf (COTS) technologies. ATLAS establishes a modern and versatile platform for fast and easy development, research and innovation. The whole system (except antenna and power amplifiers) was tested in a setup with a major reflector of opportunity at a well defined range. The obtained range profiles show that the target can be easily detected. This marks a major step on the functional testing of the system and on getting closer to an operational system capable of detecting objects in orbit.

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J. Pandeirada, M. Bergano, P. Marques, et. al.
Thu, 4 Nov 21
14/73

Comments: Manuscript presented at the International Astronautical Congress, IAC 2021, Dubai, United Arab Emirates, 25 – 29 October 2021. Copyright by IAF

The IXPE Instrument Calibration Equipment [IMA]

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http://arxiv.org/abs/2111.02066


The Imaging X-ray Polarimetry Explorer is a mission dedicated to the measurement of X-ray polarization from tens of astrophysical sources belonging to different classes. Expected to be launched at the end of 2021, the payload comprises three mirrors and three focal plane imaging polarimeters, the latter being designed and built in Italy. While calibration is always an essential phase in the development of high-energy space missions, for IXPE it has been particularly extensive both to calibrate the response to polarization, which is peculiar to IXPE, and to achieve a statistical uncertainty below the expected sensitivity. In this paper we present the calibration equipment that was designed and built at INAF-IAPS in Rome, Italy, for the calibration of the polarization-sensitive focal plane detectors on-board IXPE. Equipment includes calibration sources, both polarized and unpolarized, stages to align and move the beam, test detectors and their mechanical assembly. While all these equipments were designed to fit the specific needs of the IXPE Instrument calibration, their versatility could also be used in the future for other projects.

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F. Muleri, R. Piazzolla, A. Marco, et. al.
Thu, 4 Nov 21
41/73

Comments: 17 pages, 25 figures

Nucleation efficiency of nuclear recoils in bubble chambers [IMA]

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http://arxiv.org/abs/2111.01175


Bubble chambers using liquid xenon (and liquid argon) have been operated (resp. planned) by the Scintillating Bubble Chamber (SBC) collaboration for GeV-scale dark matter searches and CE$\nu$NS from reactors. This will require a robust calibration program of the nucleation efficiency of low-energy nuclear recoils in these target media. Such a program has been carried out by the PICO collaboration, which aims to directly detect dark matter using $\mathrm{C_3 F_8}$ bubble chambers. Neutron calibration data from mono-energetic neutron beam and Am-Be source has been collected and analyzed, leading to a global fit of a generic nucleation efficiency model for carbon and fluorine recoils, at thermodynamic thresholds of $2.45$ and $3.29\,\mathrm{keV}$. Fitting the many-dimensional model to the data ($34$ free parameters) is a non-trivial computational challenge, addressed with a custom Markov Chain Monte Carlo approach, which will be presented. Parametric MC studies undertaken to validate this methodology are also discussed. This fit paradigm demonstrated for the PICO calibration will be applied to existing and future scintillating bubble chamber calibration data.

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D. Durnford and M. Piro
Wed, 3 Nov 21
65/106

Comments: 6 pages, 3 figures

Nanobeacon: A time calibration device for the KM3NeT neutrino telescope [IMA]

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http://arxiv.org/abs/2111.00223


The KM3NeT Collaboration is currently constructing a multi-site high-energy neutrino telescope in the Mediterranean Sea consisting of matrices of pressure-resistant glass spheres, each holding a set of 31 small-area photomultipliers. The main goals of the telescope are the observation of neutrino sources in the Universe and the measurement of the neutrino oscillation parameters with atmospheric neutrinos. Both extraterrestrial and atmospheric neutrinos are detected through the Cherenkov light induced in seawater by charged particles produced in neutrino interactions in the surrounding medium. A relative time synchronization between photomultipliers of the order of 1 ns is needed to guarantee the required angular resolution of the detector. Due to the large detector volumes to be instrumented by KM3NeT, a cost reduction of the different systems is a priority. To this end, the inexpensive Nanobeacon has been designed and developed by the KM3NeT Collaboration to be used for detector time-calibration studies. At present, more than 600 Nanobeacons have been already produced. The characterization of the optical pulse and the wavelength emission profile of the devices are critical for the time calibration. In this paper, the main features of the Nanobeacon design, production and operation, together with the main properties of the light pulse generated are described.

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S. Aiello, A. Albert, M. Alshamsi, et. al.
Tue, 2 Nov 21
79/93

Comments: N/A

Optical leakage mitigation in ortho-mode transducer detectors for microwave applications [IMA]

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http://arxiv.org/abs/2110.15857


Planar ortho-mode transducers (OMTs) are a commonly used method of coupling optical signals between waveguides and on-chip circuitry and detectors. While the ideal OMT-waveguide coupling requires minimal disturbance to the waveguide, when used for mm-wave applications the waveguide is typically constructed from two sections to allow the OMT probes to be inserted into the waveguide. This break in the waveguide is a source of signal leakage and can lead to loss of performance and increased experimental systematic errors. Here we report on the development of new OMT-to-waveguide coupling structures with the goal of reducing leakage at the detector wafer interface. The pixel to pixel optical leakage due to the gap between the coupling waveguide and the backshort is reduced by means of a protrusion that passes through the OMT membrane and electrically connects the two waveguide sections on either side of the wafer. High frequency electromagnetic simulations indicate that these protrusions are an effective method to reduce optical leakage in the gap by ~80% percent, with a ~60% filling factor, relative to an standard OMT coupling architecture. Prototype devices have been designed to characterize the performance of the new design using a relative measurement with varying filling factors. We outline the simulation setup and results, and present a chip layout and sample box that will be used to perform the initial measurements.

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R. Gualtieri, P. Barry, T. Cecil, et. al.
Mon, 1 Nov 21
53/58

Comments: 6 pages, 4 figures, conference proceeding

A New Semi-Empirical Model for Cosmic Ray Muon Flux Estimation [IMA]

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http://arxiv.org/abs/2110.14152


Cosmic ray muons have emerged as a non-conventional high-energy radiation probe to monitor dense and large objects. Muons are the most abundant cosmic radiation on Earth, however, their flux at sea level is approximately 10,000/min-m2 much less than that of induced radiation, i.e., x-rays or electron beams. Cosmic ray muon flux varies with the particle incident angle and it is frequently approximated using a cosine-squared which can introduce large errors for high zenith angles. However, the cosmic ray muon flux depends on not only the zenith angle but also on the effective solid angle and the geometric characteristics of the detectors. Since the low muon flux typically results in long measurement times, an accurate estimation of the measurable muon counts is important for many muon applications. Here we propose a simple and versatile semi-empirical model to improve the accuracy in muon flux estimation at all zenith angles by incorporating the geometric parameters of detectors. We call this the Effective solid angle model. To demonstrate the functionality of our model, we compare with i) cosmic ray muon measurements, ii) the cosine-squared model, and iii) Monte-Carlo simulations. Our results show that the muon count rate estimation capability is significantly improved resulting in a reduced mean relative error from 30 % (for the cosine-squared model) to less than 15 % for the effective solid angle model. In addition, this model is simple enough and works universally for all detector geometries and configurations. By selecting an appropriate intensity correlation, the model can be easily extended to estimate muon flux at any altitude and underground level. Finally, a simple empirical correlation is derived in order to compute the expected cosmic ray muon counts in a single step.

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J. Bae and S. Chatzidakis
Thu, 28 Oct 21
30/76

Comments: N/A

The First Interstellar Astronauts Will Not Be Human [EPA]

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http://arxiv.org/abs/2110.13080


Our ability to explore the cosmos by direct contact has been limited to a small number of lunar and interplanetary missions. However, the NASA Starlight program points a path forward to send small, relativistic spacecraft far outside our solar system via standoff directed-energy propulsion. These miniaturized spacecraft are capable of robotic exploration but can also transport seeds and organisms, marking a profound change in our ability to both characterize and expand the reach of known life. Here we explore the biological and technological challenges of interstellar space biology, focusing on radiation-tolerant microorganisms capable of cryptobiosis. Additionally, we discuss planetary protection concerns and other ethical considerations of sending life to the stars.

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S. Lantin, S. Mendell, G. Akkad, et. al.
Tue, 26 Oct 21
5/109

Comments: 17 pages, 3 figures

Compact Scintillator Array Detector (ComSAD) for sounding rocket and CubeSat missions [CL]

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http://arxiv.org/abs/2110.12500


The developments of sounding rocket and CubeSat are a total game changer to the space program and it allows building space instruments to be more achievable and affordable. Therefore, it gives us a good opportunity to build a small cosmic ray detector which has capabilities to measure the flux, direction, and even energy of cosmic rays at the height above the limitation of balloon experiments, and it may open a new door for the cosmic ray physics. Compact Scintillator Array Detector (ComSAD) is dedicated for the sounding rocket mission of Taiwan’s National Space Organization. In paper, we present the idea, design, and performance of ComSAD which is also suitable for CubeSat missions in the future.

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P. Wang, C. Chen, H. Hsu, et. al.
Tue, 26 Oct 21
36/109

Comments: N/A

Dark matter Axion search with riNg Cavity Experiment DANCE: Design and development of auxiliary cavity for simultaneous resonance of linear polarizations [CL]

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http://arxiv.org/abs/2110.12023


Axion-like particles (ALPs) are undiscovered pseudo-scalar particles that are candidates for ultralight dark matter. ALPs interact with photons slightly and cause the rotational oscillation of linearly polarized light. Dark matter Axion search with riNg Cavity Experiment (DANCE) searches for ALP dark matter by amplifying the rotational oscillation with a bow-tie ring cavity. Simultaneous resonance of linear polarizations is necessary to amplify both the carrier field and the ALP signal, and to achieve the design sensitivity. The sensitivity of the current prototype experiment DANCE Act-1 is less than expectation by around three orders of magnitude due to the resonant frequency difference between s- and p-polarization in the bow-tie ring cavity. In order to tune the resonant frequency difference, the method of introducing an auxiliary cavity was proposed. We designed an auxiliary cavity that can cancel out the resonant frequency difference and realize simultaneous resonance, considering optical loss. We also confirmed that the sensitivity of DANCE Act-1 with the auxiliary cavity can reach the original sensitivity.

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H. Fujimoto, Y. Oshima, M. Ando, et. al.
Tue, 26 Oct 21
74/109

Comments: 4 pages, 4 figures, Proceedings for the 17th International Conference on Topics in Astroparticle and Underground Physics, online, August 26 – September 3, 2021

First observation and analysis of DANCE: Dark matter Axion search with riNg Cavity Experiment [CL]

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http://arxiv.org/abs/2110.10607


Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed to search for axion dark matter [Phys. Rev. Lett. 121, 161301 (2018)]. We aim to detect the rotation and oscillation of optical linear polarization caused by axion-photon coupling with a bow-tie cavity. DANCE can improve the sensitivity to axion-photon coupling constant $g_{a \gamma}$ for axion mass $m_a < 10^{-10}~\rm{eV}$ by several orders of magnitude compared to the best upper limits at present. A prototype experiment DANCE Act-1 is ongoing to demonstrate the feasibility of the method and to investigate technical noises. The optics was assembled and the performance of the cavity was evaluated. The first 12-day observation was successfully performed in May 2021. We reached $3 \times 10^{-6}~\rm{rad/\sqrt{Hz}}$ at $10~\rm{Hz}$ in the one-sided amplitude spectral density of the rotation angle of linear polarization.

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Y. Oshima, H. Fujimoto, M. Ando, et. al.
Fri, 22 Oct 21
3/133

Comments: 5 pages, 3 figures, Proceedings for the 17th International Conference on Topics in Astroparticle and Underground Physics, online, August 26 – September 3, 2021. arXiv admin note: substantial text overlap with arXiv:2105.06252

Mechanical strength and millimeter-wave transmittance spectrum of stacked sapphire plates bonded by sodium silicate solution [IMA]

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http://arxiv.org/abs/2110.07989


The polarization modulator unit for the low-frequency telescope in LiteBIRD employs an achromatic half-wave plate (AHWP). It consists of five layers of a-cut sapphire plate, which are stacked based on a Pancharatnam recipe. In this way, the retardance of the AHWP is a half-wave over a bandwidth of 34-161 GHz. The diameter of a single sapphire plate is about 500 mm and the thickness is 5 mm. When a large diameter AHWP is used for a space mission, it is important for the AHWP to survive launch vibration. A preliminary study indicates that the five-layer stacked HWP has a risk of breakage at the launch unless the five layers are glued together and mechanically treated as one disk. We report our investigation using a sodium silicate solution that can bond the sapphire plates. This technique has been previously investigated as a candidate of cryogenic bonding for a mirror material, including sapphire, of the gravitational wave experiments: LIGO, VIRGO, and KAGRA. We experimentally studied the mechanical strength of the bonded interface for two different surface conditions: polished and unpolished. We demonstrated that the tensile and shear strength > 20 MPa for samples with a polished surface. This satisfied the requirement of 5.5 MPa derived from the mechanical simulation assuming a launch load of 30G. We identified that samples glued on a polished surface exhibit higher strength than unpolished ones by a factor of 2 for tensile and 18 for shear strength. We measured the millimeter-wave transmittance between 90 and 140 GHz using sapphire plates with a diameter of 50 mm before and after bonding. We did not find any optical effects caused by the bonded interface within 2% error in transmittance, which originates from the measurement system.

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T. Toda, Y. Sakurai, H. Ishino, et. al.
Mon, 18 Oct 21
55/68

Comments: 24 pages,10 figures

Model and Measurements of an Optical Stack for Broadband Visible to Near-IR Absorption in TiN KIDs [CL]

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http://arxiv.org/abs/2110.05787


Typical materials for optical Kinetic Inductance Detetectors (KIDs) are metals with a natural absorption of 30-50% in the visible and near-infrared. To reach high absorption efficiencies (90-100%) the KID must be embedded in an optical stack. We show an optical stack design for a 60 nm TiN film. The optical stack is modeled as sections of transmission lines, where the parameters for each section are related to the optical properties of each layer. We derive the complex permittivity of the TiN film from a spectral ellipsometry measurement. The designed optical stack is optimised for broadband absorption and consists of, from top (illumination side) to bottom: 85 nm SiOx, 60 nm TiN, 23 nm of SiOx, and a 100 nm thick Al mirror. We show the modeled absorption and reflection of this stack, which has >80% absorption from 400 nm to 1550 nm and near-unity absorption for 500 nm to 800 nm. We measure transmission and reflection of this stack with a commercial spectrophotometer. The results are in good agreement with the model.

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K. Kouwenhoven, I. Elwakil, J. Wingerden, et. al.
Wed, 13 Oct 21
29/80

Comments: 7 pages, 5 figures, submitted to Journal of Low Temperature Physics

Search for "Invisible" Axion Dark Matter in the $3.3\text{-}4.2~μ$eV Mass Range [CL]

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http://arxiv.org/abs/2110.06096


We report the results from a haloscope search for axion dark matter in the $3.3\text{-}4.2~{\mu}$eV mass range. This search excludes the axion-photon coupling predicted by one of the benchmark models of “invisible” axion dark matter, the KSVZ model. This sensitivity is achieved using a large-volume cavity, a superconducting magnet, an ultra low noise Josephson parametric amplifier, and sub-Kelvin temperatures. The validity of our detection procedure is ensured by injecting and detecting blind synthetic axion signals.

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A. Collaboration, C. Bartram, T. Braine, et. al.
Wed, 13 Oct 21
67/80

Comments: 6 pages, 5 figures

Characterization of the scintillation time response of liquid argon detectors for dark matter search [CL]

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http://arxiv.org/abs/2110.05350


The scintillation time response of liquid argon has a key role in the discrimination of electronic backgrounds in dark matter search experiments. However, its extraordinary rejection power can be affected by various detector effects such as the delayed light emission of TetraPhenyl Butadiene, the most commonly used wavelength shifter, and the electric drift field applied in Time Projection Chambers. In this work, we characterized the TetraPhenyl Butadiene delayed response and the dependence of the pulse shape discrimination on the electric field, exploiting the data acquired with the ARIS, a small-scale single-phase liquid argon detector exposed to monochromatic neutron and gamma sources at the ALTO facility of IJC Lab in Orsay.

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P. Agnes, S. Cecco, A. Fan, et. al.
Tue, 12 Oct 21
3/73

Comments: 13 pages, 7 figures, 1 table

The dark matter: DAMA/LIBRA and its perspectives [CL]

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http://arxiv.org/abs/2110.04734


Experimental observations and theoretical arguments point out that Dark Matter (DM) particles are one of the most prominent component of the Universe. This motivated the pioneer DAMA experiment to investigate the presence of these particles in the galactic halo, by exploiting the model independent signature of the DM annual modulation of the rate and very highly radio-pure apparatus in underground site. In this paper the results obtained by other two annual cycles of DAMA/LIBRA-phase2 are presented and the long-standing model-independent annual modulation effect measured by DAMA deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. with different experimental configurations is summarized. The improved experimental configuration of DAMA/LIBRA-phase2, $\simeq$ 250 kg highly radio-pure NaI(Tl), allowed to lower the software energy threshold. The total exposure of DAMA/LIBRA-phase2 over 8 annual cycles is 1.53 ton $\times$ yr. DAMA/LIBRA-phase2 confirms the evidence of a signal that meets all the requirements of the model independent Dark Matter annual modulation signature, at 11.8 $\sigma$ C.L. in the energy region (1-6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA-phase1 (2.86 ton $\times$ yr), the achieved C.L. is 13.7 $\sigma$; the modulation amplitude of the single-hit scintillation events is: $(0.01014 \pm 0.00074)$ cpd/kg/keV, the measured phase is $(142.4 \pm 4.2)$ days and the measured period is $(0.99834 \pm 0.00067)$ yr, all these values are well in agreement with those expected for DM particles. No systematics or side reaction able to mimic the exploited DM signature (i.e. to account for the whole measured modulation amplitude and to simultaneously satisfy all the requirements of the signature), has been found or suggested by anyone throughout some decades thus far.

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R. Bernabei, P. Belli, V. Caracciolo, et. al.
Tue, 12 Oct 21
70/73

Comments: Proceedings of the Sixteenth Marcel Grossmann Meeting – MG16, July 5-10, 2021. arXiv admin note: substantial text overlap with arXiv:1805.10486, arXiv:1308.5109, arXiv:1002.1028, arXiv:1306.1411

Scattering efficiencies measurements of soft protons at grazing incidence from an Athena Silicon Pore Optics sample [IMA]

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http://arxiv.org/abs/2110.04122


Soft protons are a potential threat for X-ray missions using grazing incidence optics, as once focused onto the detectors they can contribute to increase the background and possibly induce radiation damage as well. The assessment of these undesired effects is especially relevant for the future ESA X-ray mission Athena, due to its large collecting area. To prevent degradation of the instrumental performance, which ultimately could compromise some of the scientific goals of the mission, the adoption of ad-hoc magnetic diverters is envisaged. Dedicated laboratory measurements are fundamental to understand the mechanisms of proton forward scattering, validate the application of the existing physical models to the Athena case and support the design of the diverters. In this paper we report on scattering efficiency measurements of soft protons impinging at grazing incidence onto a Silicon Pore Optics sample, conducted in the framework of the EXACRAD project. Measurements were taken at two different energies, ~470 keV and ~170 keV, and at four different scattering angles between 0.6 deg and 1.2 deg. The results are generally consistent with previous measurements conducted on eROSITA mirror samples, and as expected the peak of the scattering efficiency is found around the angle of specular reflection.

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R. Amato, S. Diebold, A. Guzman, et. al.
Mon, 11 Oct 21
26/58

Comments: 16 pages, 11 figures; accepted for publication on Experimental Astronomy

Testing the new QSM-6M optical module with the NEVOD Cherenkov water detector [IMA]

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http://arxiv.org/abs/2110.02676


The method for studying characteristics of the response of optical modules of neutrino telescopes to various classes of events registered in the volume of the Cherenkov water detector NEVOD is discussed. Results of testing of an optical module with Hamamatsu R877 photomultiplier in single muon events and in events with high energy deposit are presented.

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S. Khokhlov, T. Karetnikova, V. Kindin, et. al.
Thu, 7 Oct 21
16/51

Comments: N/A

Assessing the quality of a network of vector-field sensors [CL]

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http://arxiv.org/abs/2110.02923


An experiment consisting of a network of sensors can endow several advantages over an experiment with a single sensor: improved sensitivity, error corrections, spatial resolution, etc. However, there is often a question of how to optimally set up the network to yield the best results. Here, we consider a network of devices that measure a vector field along a given axis; namely for magnetometers in the Global Network of Optical Magnetometers for Exotic physics searches (GNOME). We quantify how well the network is arranged, explore characteristics and examples of ideal networks, and characterize the optimal configuration for GNOME. We find that by re-orienting the sensitive axes of existing magnetometers, the sensitivity of the network can be improved by around a factor of two.

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J. Smiga
Thu, 7 Oct 21
18/51

Comments: 7 pages, 2 figures, 2 tables

The CaloCube calorimeter for high-energy cosmic-ray measurements in space: performance of a large-scale prototype [CL]

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http://arxiv.org/abs/2110.01561


The direct observation of high-energy cosmic rays, up to the PeV energy region, will increasingly rely on highly performing calorimeters, and the physics performance will be primarily determined by their geometrical acceptance and energy resolution. Thus, it is extremely important to optimize their geometrical design, granularity and absorption depth, with respect to the totalmass of the apparatus, which is amongst the most important constraints for a space mission. CaloCube is an homogeneous calorimeter whose basic geometry is cubic and isotropic, obtained by filling the cubic volume with small cubic scintillating crystals. In this way it is possible to detect particles arriving from every direction in space, thus maximizing the acceptance. This design summarizes a three-year R&D activity, aiming to both optimize and study the full-scale performance of the calorimeter, in the perspective of a cosmic-ray space mission, and investigate a viable technical design by means of the construction of several sizable prototypes. A large scale prototype, made of a mesh of 5x5x18 CsI(Tl) crystals, has been constructed and tested on high-energy particle beams at CERN SPS accelerator. In this paper we describe the CaloCube design and present the results relative to the response of the large scale prototype to electrons.

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O. Adriani, A. Agnesi, S. Albergo, et. al.
Tue, 5 Oct 21
23/72

Comments: 24 pages, 19 figures

Measuring the Quantum Efficiency of X-Ray Hybrid CMOS Detectors [IMA]

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http://arxiv.org/abs/2110.01531


Next-generation X-ray observatories, such as the Lynx X-ray Observatory Mission Concept, will require detectors with high quantum efficiency (QE) across the soft X-ray band to observe the faint objects that drive their mission science cases. Hybrid CMOS Detectors (HCDs), a form of active-pixel sensor, are promising candidates for use on these missions because of their faster read-out, lower power consumption, and greater radiation hardness than detectors used in the current generation of X-ray telescopes. In this work, we present QE measurements of a Teledyne H2RG HCD. These measurements were performed using a gas-flow proportional counter as a reference detector to measure the absolute flux incident on the HCD. We find an effective QE of $95.0 \pm 1.1\%$ at the Mn K$\alpha$/K$\beta$ lines (at 5.9 and 6.5 keV), $98.5 \pm 1.8\%$ at the Al K$\alpha$ line (1.5 keV), and $85.0 \pm 2.8\%$ at the O K$\alpha$ line (0.52 keV).

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J. Colosimo, A. Falcone, M. Wages, et. al.
Tue, 5 Oct 21
39/72

Comments: 11 pages, 8 figures, appears in Proc. SPIE 2021

First Constraints on Dark Photon Dark Matter with Superconducting Nanowire Detectors in an Optical Haloscope [CL]

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http://arxiv.org/abs/2110.01582


Uncovering the nature of dark matter is one of the most important goals of particle physics. Light bosonic particles, such as the dark photon, are well-motivated candidates: they are generally long-lived, weakly-interacting, and naturally produced in the early universe. In this work, we report on LAMPOST (Light A$\prime$ Multilayer Periodic Optical SNSPD Target), a proof-of-concept experiment searching for dark photon dark matter in the eV mass range, via coherent absorption in a multi-layer dielectric haloscope. Using a superconducting nanowire single-photon detector (SNSPD), we achieve efficient photon detection with a dark count rate (DCR) of 6×10^-6 counts/sec. The observed count rate in our detector differed insignificantly from a reference SNSPD, enabling our prototype experiment to set new limits for the dark photon dark matter kinetic mixing parameter $\epsilon$ < 10^-12 and find no evidence for dark photon dark matter over a mass range of 0.7-0.8 eV (photon wavelength 1550-1770 nm). This performance demonstrates that, with feasible upgrades, our architecture could probe significant new parameter space for dark photon and axion dark matter in the meV to 10 eV mass range.

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J. Chiles, I. Charaev, R. Lasenby, et. al.
Tue, 5 Oct 21
53/72

Comments: N/A

Optimization of a CCD-in-CMOS TDI detector's operating clock voltages by Taguchi based Grey relational analysis [CL]

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http://arxiv.org/abs/2110.00299


In recent years, CCD-in-CMOS TDI image sensors are becoming increasingly popular for many small satellite missions to assure a fast and affordable access to space for Low Earth Observation. Our monolithic CCD-in-CMOS TDI imager features a specifically developed technology which combines the benefits of a classical CCD TDI with the advantages of CMOS System-On-a-Chip (SoC) design. Like CCD, this detector is also controlled by a large number of clock voltages. Optimizing these voltages allows to increase the performance of the detector by improving multiple characteristic parameters, such as full well capacity (FWC), dark current, linearity, dark signal non-uniformity (DSNU) and charge transfer efficiency (CTE). Traditionally, it has been the standard practice to adjust the CCD voltages by trial and error methods to get a better image. Because of the large parameter space, such subjective procedures may yield far from the optimum performance. This paper reports a design of experiments (DOE) technique applied on the clock voltages to improve the multiple performance parameters of the detector. This method utilizes the Taguchi’s orthogonal arrays of experiments to reduce the number of experiments with different voltage combinations. Finally, optimal combination of clock voltages is obtained by converting the multiple performance parameters of the detector into a single Grey relational grade. In this process, the sequences of obtaining parameter values are categorized according to the performance characteristics. The condition Higher-the-better is used for parameters like FWC and CTE whereas condition Lower-the-better is applied for parameters, such as dark current, linearity error and DSNU.

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S. Mahato and P. Boulenc
Mon, 4 Oct 21
67/76

Comments: N/A

Multispectral CCD-in-CMOS Time Delay Integration imager for high resolution Earth observation [IMA]

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http://arxiv.org/abs/2109.14532


Many future small satellite missions are aimed to provide low-cost remote sensing data at unprecedented revisit rates, with a ground resolution of less than one meter. This requires high resolution, fast and sensitive line-scan imagers operating at low power consumption and ideally featuring spectral sensitivity. In this paper we present comprehensive characterization results of our 7 band Back-Side Illuminated (BSI) CCD-in-CMOS sensor with a pixel pitch of 5.4 um. We have extensively characterized the key performance parameters of our CCD-in-CMOS sensor, such as quantum efficiency (QE), full well capacity (FWC), read noise, conversion gain, non-linearity, dark current etc. Novelty of this device is the combination of 7 TDI bands on the same imager allowing simultaneous multispectral TDI capture. Glass-based broadband filters with a typical band-pass width of about 100 nm have been developed and glued together to form a filter assembly of 6 band-pass filters and one panchromatic channel. Multispectral capability of this sensor is particularly interesting for Low Earth Observation (LEO) applications such as environmental monitoring, precision agriculture, disaster detection and monitoring. To highlight its ad-vantages for use in vegetation observation, we demonstrated a fake leaf and a real leaf imaging using a 7 band BSI sensor with integrated filters operating in 7-band mode at 15 kHz.

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S. Mahato, S. Thijs, J. Bentell, et. al.
Thu, 30 Sep 21
5/82

Comments: N/A

The Forward Physics Facility: Sites, Experiments, and Physics Potential [CL]

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http://arxiv.org/abs/2109.10905


The Forward Physics Facility (FPF) is a proposal to create a cavern with the space and infrastructure to support a suite of far-forward experiments at the Large Hadron Collider during the High Luminosity era. Located along the beam collision axis and shielded from the interaction point by at least 100 m of concrete and rock, the FPF will house experiments that will detect particles outside the acceptance of the existing large LHC experiments and will observe rare and exotic processes in an extremely low-background environment. In this work, we summarize the current status of plans for the FPF, including recent progress in civil engineering in identifying promising sites for the FPF and the experiments currently envisioned to realize the FPF’s physics potential. We then review the many Standard Model and new physics topics that will be advanced by the FPF, including searches for long-lived particles, probes of dark matter and dark sectors, high-statistics studies of TeV neutrinos of all three flavors, aspects of perturbative and non-perturbative QCD, and high-energy astroparticle physics.

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L. Anchordoqui, A. Ariga, T. Ariga, et. al.
Wed, 29 Sep 21
53/78

Comments: 74 pages, 30 figures

Three years of muography at Mount Etna: results and perspectives [IMA]

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http://arxiv.org/abs/2109.13125


The Summit Craters system represents the point of maximum expression of the persistent tectonic activity at Mount Etna Volcano. The Muography of Etna Volcano (MEV) Project began in 2016 as a pilot project for the successive installation of a permanent muographic observatory. It aims to demonstrate the detector’s capability to observe density anomalies inside the volcanic edifice and monitor their time evolution. The first muon telescope built by the collaboration and installed at the base of the North-East Crater from August 2017 to October 2019 was already able to get significant results. This work describes the characteristics of the muon-telescope and summarizes the main results obtained, with a quick look at the current status of the project and future developments.

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G. Gallo, D. Presti, D. Bonanno, et. al.
Tue, 28 Sep 21
20/89

Comments: N/A

Point Absorber Limits to Future Gravitational-Wave Detectors [CL]

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http://arxiv.org/abs/2109.08743


High-quality optical resonant cavities require low optical loss, typically on the scale of parts per million. However, unintended micron-scale contaminants on the resonator mirrors that absorb the light circulating in the cavity can deform the surface thermoelastically, and thus increase losses by scattering light out of the resonant mode. The point absorber effect is a limiting factor in some high-power cavity experiments, for example, the Advanced LIGO gravitational wave detector. In this Letter, we present a general approach to the point absorber effect from first principles and simulate its contribution to the increased scattering. The achievable circulating power in current and future gravitational-wave detectors is calculated statistically given different point absorber configurations. Our formulation is further confirmed experimentally in comparison with the scattered power in the arm cavity of Advanced LIGO measured by in-situ photodiodes. The understanding presented here provides an important tool in the global effort to design future gravitational wave detectors that support high optical power, and thus reduce quantum noise.

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W. Jia, H. Yamamoto, K. Kuns, et. al.
Tue, 21 Sep 21
37/85

Comments: 7 pages, 3 figures

A compact six degree of freedom seismometer with interferometric readout [CL]

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http://arxiv.org/abs/2109.07880


Ground vibrations couple to the longitudinal and angular motion of the aLIGO test masses and limit the observatory sensitivity below 30\,Hz. Novel inertial sensors have the potential to improve the aLIGO sensitivity in this band and simplify the lock acquisition of the detectors. In this paper, we experimentally study a compact 6D seismometer that consists of a mass suspended by a single wire. The position of the mass is interferometrically read out relative to the platform that supports the seismometer. We present the experimental results, discuss limitations of our metallic prototype, and show that a compact 6D seismometer made out of fused silica and suspended with a fused silica fibre has the potential to improve the aLIGO low frequency noise.

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A. Ubhi, J. Smetana, T. Zhang, et. al.
Fri, 17 Sep 21
64/67

Comments: N/A

A measurement of the mean electronic excitation energy of liquid xenon [CL]

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http://arxiv.org/abs/2109.07151


Detectors using liquid xenon as target are widely deployed in rare event searches. Conclusions on the interacting particle rely on a precise reconstruction of the deposited energy which requires calibrations of the energy scale of the detector by means of radioactive sources. However, a microscopic calibration, i.e. the translation from the number of excitation quanta into deposited energy, also necessitates good knowledge of the energy required to produce single scintillation photons or ionisation electrons in liquid xenon. The sum of these excitation quanta is directly proportional to the deposited energy in the target. The proportionality constant is the mean excitation energy and is commonly known as $W$-value. Here we present a measurement of the $W$-value with electronic recoil interactions in a small dual-phase xenon time projection chamber with a hybrid (photomultiplier tube and silicon photomultipliers) photosensor configuration. Our result is based on calibrations at $\mathcal{O}(1-10 \, \mathrm{keV})$ with internal $^{37}$Ar and $^{83\text{m}}$Kr sources and single electron events. We obtain a value of $W=11.5 \, ^{+0.2}_{-0.3} \, \mathrm{(syst.)} \, \mathrm{eV}$, with negligible statistical uncertainty, which is lower than previously measured at these energies. If further confirmed, our result will be relevant for modelling the absolute response of liquid xenon detectors to particle interactions.

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L. Baudis, P. Sanchez-Lucas and K. Thieme
Thu, 16 Sep 21
17/54

Comments: 11 pages, 4 figures

Performance evaluation of GAGG(Ce)/LFS scintillator + MPPC array readout with ASIC [CL]

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http://arxiv.org/abs/2109.07362


We constructed a gamma-ray detector by combining two types of scintillator array detectors with an MPPC array and evaluated the spectral performance by reading out the signals from the MPPC with a low-power integrated circuit (ASIC) manufactured by IDEAS in Norway. One of the two types of scintillators is a GAGG(Ce) (Ce-doped $ \rm{Gd_3Al_2Ga_3O_{12}}$) scintillator, and the other is an LFS scintillator. The scintillator array is 2.5 cm $\times$ 2.5 cm in size and is coated with $ \rm{BaSO_4}$-based white paint for GAGG(Ce) and an enhanced specular reflector (ESR) for LFS except for the side optically coupled to the MPPC. The spectra derived from the array are affected by the MPPC photon saturations and light leakage from the adjacent pixels, and we carefully corrected for both effects in our data analysis. The energy resolution of 662 keV at 20 $^\circ$C is 6.10$\pm$0.04\% for the GAGG(Ce) scintillator array and 8.57$\pm$0.15\% for the LFS scintillator array, this is equivalent to the typical energy resolution found in the references. The energy resolution depends on the temperature: the energy resolution improves as the temperature decreases. We found that the contribution of thermal noise from the MPPCs to the energy resolution is negligible within the range of –20 to 40 $^\circ$C, and the energy resolution is mainly determined by the light yield of the crystals.

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D. Nobashi, K. Yamaoka, H. Tajima, et. al.
Thu, 16 Sep 21
35/54

Comments: 13 pages, 9 figures

KM3NeT Detection Unit Line Fit reconstruction using positioning sensors data [IMA]

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http://arxiv.org/abs/2109.04914


The KM3NeT collaboration is constructing two large neutrino detectors in the Mediterranean Sea: ARCA, located near Sicily and aiming at neutrino astronomy, and ORCA, located near Toulon and designed for neutrino oscillation studies. The two detectors, together, will have hundreds of Detection Units (DUs) with 18 Digital Optical Modules (DOMs) maintained vertical by buoyancy, forming a large 3D optical array for detecting the Cherenkov light produced after the neutrino interactions. To properly reconstruct the direction of the incoming neutrino, the position of the DOMs must be known precisely with an accuracy of less than 10 cm. For this purpose, there are acoustic and orientation sensors inside the DOMs. An Attitude Heading Reference System (AHRS) chip provides the components values of the Acceleration and Magnetic field in the DOM, from which it is possible to calculate Yaw, Pitch, and Roll for each floor of the line. A piezo sensor detects the signals from fixed acoustic emitters on the seafloor, so as to position it by trilateration. Data from these sensors are used as an input to reconstruct the shape of the entire line based on a DU Line Fit mechanical model. This proceeding presents an overview of the KM3NeT monitoring system, as well as the line fit model and a selection of results.

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D. D.Tortosa and C. Poirè
Mon, 13 Sep 21
10/52

Comments: 6 pages

Interferometric sensing of a commercial geophone [CL]

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http://arxiv.org/abs/2109.03147


We present a modified commercial L-4C geophone with interferometric readout that demonstrated a resolution 60 times lower than the included coil-magnet readout at low frequencies. The intended application for the modified sensor is in vibration isolation platforms that require improved performance at frequencies lower than 1 Hz. A controls and noise-model of an Advanced LIGO ‘HAM-ISI’ vibration isolation system was developed, and it shows that our sensor can reduce the residual vibration by a factor of 70 at 0.1 Hz

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S. Cooper, C. Collins, L. Prokhorov, et. al.
Wed, 8 Sep 21
71/76

Comments: N/A

Hardware-accelerated Inference for Real-Time Gravitational-Wave Astronomy [CL]

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http://arxiv.org/abs/2108.12430


The field of transient astronomy has seen a revolution with the first gravitational-wave detections and the arrival of multi-messenger observations they enabled. Transformed by the first detection of binary black hole and binary neutron star mergers, computational demands in gravitational-wave astronomy are expected to grow by at least a factor of two over the next five years as the global network of kilometer-scale interferometers are brought to design sensitivity. With the increase in detector sensitivity, real-time delivery of gravitational-wave alerts will become increasingly important as an enabler of multi-messenger followup. In this work, we report a novel implementation and deployment of deep learning inference for real-time gravitational-wave data denoising and astrophysical source identification. This is accomplished using a generic Inference-as-a-Service model that is capable of adapting to the future needs of gravitational-wave data analysis. Our implementation allows seamless incorporation of hardware accelerators and also enables the use of commercial or private (dedicated) as-a-service computing. Based on our results, we propose a paradigm shift in low-latency and offline computing in gravitational-wave astronomy. Such a shift can address key challenges in peak-usage, scalability and reliability, and provide a data analysis platform particularly optimized for deep learning applications. The achieved sub-millisecond scale latency will also be relevant for any machine learning-based real-time control systems that may be invoked in the operation of near-future and next generation ground-based laser interferometers, as well as the front-end collection, distribution and processing of data from such instruments.

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A. Gunny, D. Rankin, J. Krupa, et. al.
Tue, 31 Aug 21
60/73

Comments: 21 pages, 14 figures

PMT gain calibration and monitoring based on highly compressed hit information in KM3NeT [IMA]

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http://arxiv.org/abs/2108.11467


The cubic-kilometre neutrino telescope, which consists of large-scale 3D-arrays of photomultiplier tubes (PMTs) currently under construction on the Mediterranean seabed, relies on accurate calibration procedures in order to answer its science goals. These proceedings present the gain calibration method used in KM3NeT, which is based on highly compressed PMT hit information. In particular, it is shown that the PMT gains can be tuned to within 2% of the nominal value, based on the measured single photoelectron time-over-threshold distribution of each PMT.

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B. Jung, M. Jong and P. Fermani
Fri, 27 Aug 21
16/67

Comments: 6 pages, 4 figures. Proceedings for the VLVnT 2021 conference, submitted to JINST

Tomographic Imaging by a Si/CdTe Compton Camera for In-111 and I-131 Radionuclides [CL]

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http://arxiv.org/abs/2108.10149


Tomographic imaging with radionuclides commonly used in nuclear medicine, such as $^{111}$In (171 and 245 keV) and $^{131}$I (364 keV), is in high demand for medical applications and small animal imaging. The Si/CdTe Compton camera with its high angular and high energy resolutions is an especially promising detector to extend the energy coverage for imaging to the range that covers gamma-ray emitted from these radionuclides. Here, we take the first steps towards short-distance imaging by conducting experiments using three-dimensional phantoms composed of multiple sphere-like solutions of $^{111}$In and $^{131}$I with a diameter of 2.7 mm, placed at a distance of 41 mm. Using simple back-projection methods, the positions of the sources are reproduced with a spatial resolution of 11.5 mm and 9.0 mm (FWHM) for $^{111}$In and $^{131}$I, respectively. We found that a LM-MLEM method gives a better resolution of 4.0 mm and 2.7 mm (FWHM). We resolve source positions of a tetrahedron structure with a source-to-source separation of 28 mm. These findings demonstrate that Compton Cameras have the potential of close-distance imaging of radioisotopes distributions in the energy range below 400 keV.

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G. Yabu, H. Yoneda, T. Orita, et. al.
Tue, 24 Aug 21
21/76

Comments: N/A

The rise of muon content in extensive air showers after the 3 PeV knee of the primary cosmic ray spectrum according to data of the Tien Shan mountain installation [HEAP]

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http://arxiv.org/abs/2108.09921


We put together the experimental results on muon component of extensive air showers (EAS) which were gained with various techniques at the detector complex of the Tien Shan mountain station. According to this comparison, the problem of the EAS muon content in the range of primary cosmic ray energies (1-100)PeV seems to be more complicated than it was usually supposed. Generally, from the models of nuclear interaction it follows that the EAS which have produced gamma-hadron families in the Tien Shan X-ray emulsion chamber did preferably originate from interaction of the light cosmic ray nuclei, such that their muon abundance must be ~1.5 times below an average calculated over all showers. In contrary, the experimental muon counts in the EAS with families demonstrate a (1.5-2)-fold excess above the average, and this difference starts to be observable in the showers with the energy above the 3PeV knee of the primary cosmic ray spectrum. Later on, the rise of muon production in EAS after the knee was confirmed at Tien Shan by another experiment on detection of the neutrons stemmed from interaction of cosmic ray muons. Thus, the results obtained by the two completely different methods do mutually agree with each other but contradict to the common models of hadron interaction.

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A. Shepetov, S. Shaulov, O. Likiy, et. al.
Tue, 24 Aug 21
40/76

Comments: 22 pages, 11 figures Submitted to Astroparticle Physics

Implementation of a broadband focal plane estimator for high-contrast dark zones [IMA]

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http://arxiv.org/abs/2108.08200


The characterization of exoplanet atmospheres using direct imaging spectroscopy requires high-contrast over a wide wavelength range. We study a recently proposed focal plane wavefront estimation algorithm that exclusively uses broadband images to estimate the electric field. This approach therefore reduces the complexity and observational overheads compared to traditional single wavelength approaches. The electric field is estimated as an incoherent sum of monochromatic intensities with the pair-wise probing technique. This paper covers the detailed implementation of the algorithm and an application to the High-contrast Imager for Complex Aperture Telescopes (HiCAT) testbed with the goal to compare the performance between the broadband and traditional narrowband filter approaches.

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S. Redmond, L. Pueyo, L. Pogorelyuk, et. al.
Thu, 19 Aug 21
25/54

Comments: Submitted to OP21O SPIE Optical Engineering + Applications, Techniques and Instrumentation for Detection of Exoplanets X | 11 pages, 7 figures

Dark zone maintenance results for segmented aperture wavefront error drift in a high contrast space coronagraph [IMA]

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http://arxiv.org/abs/2108.08216


Due to the limited number of photons, directly imaging planets requires long integration times with a coronagraphic instrument. The wavefront must be stable on the same time scale, which is often difficult in space due to thermal variations and other mechanical instabilities. In this paper, we discuss the implications on future space mission observing conditions of our recent laboratory demonstration of a dark zone maintenance (DZM) algorithm. The experiments are performed on the High-contrast imager for Complex Aperture Telescopes (HiCAT) at the Space Telescope Science Institute (STScI). The testbed contains a segmented aperture, a pair of continuous deformable mirrors (DMs), and a lyot coronagraph. The segmented aperture injects high order wavefront aberration drifts into the system which are then corrected by the DMs downstream via the DZM algorithm. We investigate various drift modes including segmented aperture drift, all three DMs drift simultaneously, and drift correction at multiple wavelengths.

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S. Redmond, L. Pueyo, L. Pogorelyuk, et. al.
Thu, 19 Aug 21
39/54

Comments: Submitted to OP210 SPIE Optical Engineering + Applications, Techniques and Instrumentation for Detection of Exoplanets X | 14 pages, 5 figures

SiPM photon counting readout system for Ultra-Fast Astronomy [IMA]

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http://arxiv.org/abs/2108.07526


One of the new astrophysical phase spaces is exploring sky in the optical (320 nm – 650 nm) range within millisecond to nanosecond timescales known as ultra-fast astronomy (UFA). For this purpose, we developed our own customized readout system for silicon photomultiplier (SiPM) to scan the sky as fast as possible. SiPMs are capable of single-photon detection in the visible light range. The developed readout system for these detectors consists of 16 channels of 14-bit data logging. Each channel includes a 50-dB gain pre-amplifier, signal shaping circuits, analog front end, analogue to digital converter and Xilinx UltraScale+ MPSoC board for data-logging. The results of our readout system show that, scans can be done with 16 ns time frame and a power consumption of 250~mW per channel.

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A. Lau, Y. Chan, M. Shafiee, et. al.
Wed, 18 Aug 21
21/70

Comments: 9 pages, 7 figures

Colour remote sensing of the impact of artificial light at night (II): Calibration of DSLR-based images from the International Space Station [IMA]

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http://arxiv.org/abs/2108.07050


Nighttime images taken with DSLR cameras from the International Space Station (ISS) can provide valuable information on the spatial and temporal variation of artificial nighttime lighting on Earth. In particular, this is the only source of historical and current visible multispectral data across the world (DMSP/OLS and SNPP/VIIRS-DNB data are panchromatic and multispectral in the infrared but not at visible wavelengths). The ISS images require substantial processing and proper calibration to exploit intensities and ratios from the RGB channels. Here we describe the different calibration steps, addressing in turn Decodification, Linearity correction (ISO dependent), Flat field/Vignetting, Spectral characterization of the channels, Astrometric calibration/georeferencing, Photometric calibration (stars)/Radiometric correction (settings correction – by exposure time, ISO, lens transmittance, etc) and Transmittance correction (window transmittance, atmospheric correction). We provide an example of the application of this processing method to an image of Spain.

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A. Miguel, J. Zamorano, M. Aubé, et. al.
Tue, 17 Aug 21
47/56

Comments: N/A

Results on Low-Mass Weakly Interacting Massive Particles from a 11 kg d Target Exposure of DAMIC at SNOLAB (ICRC2021 Proceedings) [CEA]

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http://arxiv.org/abs/2108.05983


Experimental efforts of the last decades have been unsuccessful in detecting WIMPs (Weakly Interacting Massive Particles) in the 10-to-10$^4$ GeV/$c^2$ range, thus motivating the search for lighter dark matter. The DAMIC (DArk Matter In CCDs) at SNOLAB experiment aims for direct detection of light dark matter particles ($m_\chi <$ 10 GeV/$c^2$) by means of CCDs (Charge-Coupled Devices). Fully-depleted 675 $\mu$m-thick CCDs are used to such end. The optimized readout noise and operation at cryogenic temperatures allow for a detection threshold of 50 eV${\text{ee}}$ electron-equivalent energy. Focusing on nuclear and electronic scattering as potential detection processes, DAMIC has so far set competitive constraints on the detection of low mass WIMPs and hidden-sector particles. In this work, an 11 kg-day exposure dataset is exploited to search for light WIMPs by building the first comprehensive radioactive background model for CCDs. Different background sources are discriminated making conjoint use of the spatial distribution and energy of ionization events, thereby constraining the amount of contaminants such as tritium from silicon cosmogenic activation and surface lead-210 from radon plate-out. Despite a conspicuous, statistically-significant excess of events below 200 eV${\text{ee}}$, this analysis places the strongest exclusion limit on the WIMP-nucleon scattering cross section with a silicon target for $m_\chi <$ 9 GeV/$c^2$.

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M. Traina
Mon, 16 Aug 21
31/34

Comments: 9 pages, 4 figures, ICRC2021 conference proceedings article

Performance of the D-Egg Optical Sensor for the IceCube Upgrade [CL]

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http://arxiv.org/abs/2108.05353


New optical sensors called the “D-Egg” have been developed for cost-effective instrumentation for the IceCube Upgrade. With two 8-inch high quantum efficient photomultiplier tubes (PMTs), they offer increased effective photocathode area while retaining as much of the successful IceCube Digital Optical Module design as possible. Mass production of D-Eggs has started in 2020. By the end of 2021, there will be 310 D-Eggs produced with 288 deployed in the IceCube Upgrade. The D-Egg readout system uses advanced technologies in electronics and computing power. Each of the two PMT signals is digitised using ultra-low-power 14-bit ADCs with a sampling frequency of 240 megaSPS, enabling seamless and lossless event recording from single-photon signals to signals exceeding 200 PE within 10 nanosecond, as well as flexible event triggering. In this paper, we report the single photon detection performance as well as the multiple photon recording capability of D-Eggs from the mass production line which have been evaluated with the built-in data acquisition system.

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C. Hill, M. Meier, R. Nagai, et. al.
Fri, 13 Aug 21
37/64

Comments: Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions

A metamaterial ring with applications in broad band antennas used in radio astronomy and satellite communications [CL]

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http://arxiv.org/abs/2108.05648


Electromagnetic metamaterials at microwave frequencies are well established in industry and research. Recent work has shown how a specific kind of metallic metamaterial can contribute towards improving the performance of the feedhorn antennas used in radio astronomy and satellite telecommunications. In this article, we justify this argument, finding an innovative type of meta-ring of remarkable manufacturability with a potential to improve the state of the art in these fields. A pioneering meta-horn antenna formed of meta-rings is then fabricated and characterized in the laboratory, showing an excellent feature on an octave bandwidth, especially in terms of cross-polarization, a key figure of merit in both radio astronomy and telecommunications; and also side-lobe level, return-loss and gain.

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J. Miguel, C. Franceschet, S. Realini, et. al.
Fri, 13 Aug 21
54/64

Comments: 9 pages, 10 figures

Proton radiation hardness of X-ray SOI pixel sensors with pinned depleted diode structure [IMA]

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http://arxiv.org/abs/2108.05303


X-ray SOI pixel sensors, “XRPIX”, are being developed for the next-generation X-ray astronomical satellite, “FORCE”. The XRPIX are fabricated with the SOI technology, which makes it possible to integrate a high-resistivity Si sensor and a low-resistivity Si CMOS circuit. The CMOS circuit in each pixel is equipped with a trigger function, allowing us to read out outputs only from the pixels with X-ray signals at the timing of X-ray detection. This function thus realizes high throughput and high time resolution, which enables to employ anti-coincidence technique for background rejection. A new series of XRPIX named XRPIX6E developed with a pinned depleted diode (PDD) structure improves spectral performance by suppressing the interference between the sensor and circuit layers. When semiconductor X-ray sensors are used in space, their spectral performance is generally degraded owing to the radiation damage caused by high-energy protons. Therefore, before using an XRPIX in space, it is necessary to evaluate the extent of degradation of its spectral performance by radiation damage. Thus, we performed a proton irradiation experiment for XRPIX6E for the first time at HIMAC in the NIRS. We irradiated XRPIX6E with high-energy protons with a total dose of up to 40 krad, equivalent to 400 years of irradiation in orbit. The 40-krad irradiation degraded the energy resolution of XRPIX6E by 25 $\pm$ 3%, yielding an energy resolution of 260.1 $\pm$ 5.6 eV at the full width half maximum for 5.9 keV X-rays. However, the value satisfies the requirement for FORCE, 300 eV at 6 keV, even after the irradiation. It was also found that the PDD XRPIX has enhanced radiation hardness compared to previous XRPIX devices. In addition, we investigated the degradation of the energy resolution; it was shown that the degradation would be due to increasing energy-independent components, e.g., readout noise.

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M. Hayashida, K. Hagino, T. Kohmura, et. al.
Thu, 12 Aug 21
32/62

Comments: 15 pages, 16 figures, accepted for publication in JATIS

Theory of drain noise in high electron mobility transistors based on real-space transfer [CL]

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http://arxiv.org/abs/2108.03370


High electron mobility transistors are widely used as microwave amplifiers owing to their low microwave noise figure. Electronic noise in these devices is typically modeled by noise sources at the gate and drain. While consensus exists regarding the origin of the gate noise, that of drain noise is a topic of debate. Here, we report a theory of drain noise as a type of partition noise arising from real-space transfer of hot electrons from the channel to the barrier. The theory accounts for the magnitude and dependencies of the drain temperature and suggests strategies to realize devices with lower noise figure.

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I. Esho, A. Choi and A. Minnich
Wed, 11 Aug 21
32/72

Comments: N/A

Data Acquisition System for a Distributed Smartphone Cosmic Ray Observatory [IMA]

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http://arxiv.org/abs/2108.04803


A scientific instrument comprised of a global network of millions of independent, connected, remote devices presents unique data acquisition challenges. We describe the software design of a mobile application which collects data from smartphone cameras without overburdening the phone’s CPU or battery. The deployed software automatically calibrates to heterogeneous hardware targets to improve the quality and manage the rate of data transfer, and connects to a cloud-based data acquisition system which can manage and refine the operation of the network.

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J. Swaney, C. Shimmin and D. Whiteson
Wed, 11 Aug 21
39/72

Comments: 11 pages, 9 figures

Scintillation yield from electronic and nuclear recoils in superfluid $^4$He [CL]

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http://arxiv.org/abs/2108.02176


Superfluid $^4$He is a promising target material for direct detection of light ($<$ 1 GeV) dark matter. Possible signal channels available for readout in this medium include prompt photons, triplet excimers, and roton and phonon quasiparticles. The relative yield of these signals has implications for the sensitivity and discrimination power of a superfluid $^4$He dark matter detector. Using a 16 cm$^3$ volume of 1.75 K superfluid $^4$He read out by six immersed photomultiplier tubes, we measured the scintillation from electronic recoils ranging between 36.3 and 185 keV$\mathrm{ee}$, yielding a mean signal size of $1.12^{+0.02}{-0.03}$ phe/keV$\mathrm{ee}$, and nuclear recoils from 53.2 to 1090 keV$\mathrm{nr}$. We compare the results of our relative scintillation yield measurements to an existing semi-empirical model based on helium-helium and electron-helium interaction cross sections. We also study the behavior of delayed scintillation components as a function of recoil type and energy, a further avenue for signal discrimination in superfluid $^4$He.

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S. Collaboration, A. Biekert, C. Chang, et. al.
Thu, 5 Aug 21
51/57

Comments: 16 pages, 18 figures

Positioning system for Baikal-GVD [IMA]

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http://arxiv.org/abs/2108.00212


Baikal-GVD is a kilometer scale neutrino telescope currently under construction in Lake Baikal. Due to water currents in Lake Baikal, individual photomultiplier housings are mobile and can drift away from their initial position. In order to accurately determine the coordinates of the photomultipliers, the telescope is equipped with an acoustic positioning system. The system consists of a network of acoustic modems, installed along the telescope strings and uses acoustic trilateration to determine the coordinates of individual modems. This contribution discusses the current state of the positioning in Baikal-GVD, including the recent upgrade to the acoustic modem polling algorithm.

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V. Allakhverdyan, A. Avrorin, A. Avrorin, et. al.
Tue, 3 Aug 21
7/90

Comments: Presented at 37th International Cosmic Ray Conference (ICRC 2021)