Collective electronic pulsation of compressed atoms in Thomas-Fermi model [CL]

http://arxiv.org/abs/1402.3468


Based on the Thomas-Fermi solution for compressed atoms, we study electric pulsations of electron number-density, pressure and electric fields, which can be caused by an external perturbations acting on the atom. We numerically obtain the eigen-frequencies and eigen-functions for stationary pulsation modes that fulfill the boundary-value problem established by electron-number and energy-momentum conservation, equation of state, laws of thermodynamics, and Maxwell’s equations, as well as physical boundary conditions. The lowest-lying eigen-frequency is about a few $\rm{keV}$ depending on the atomic number $Z$ and the radius of the compressed atoms. In addition, assuming all electrons compressed to the nuclear core, which can be of either microscopic or macroscopic dimension, we obtain an analytical solution. For large Z the lowest-lying eigen-frequency of this solution $\omega_1\approx2\alpha^{1/2} \langle {\bar n}_e\rangle^{1/3}\approx 2.1\, {\rm MeV}$, when the average electron-density $\langle {\bar n}_e\rangle$ of the nuclear core is about the nuclear density. We mention the possible applications of these results to both atomic physics and astrophysics. Moreover, we discuss some possibilities to trigger or stimulate these electric pulsation modes, leading to consequences for experimental observations.

Read this paper on arXiv…

H. Ludwig, R. Ruffini and S. Xue
Mon, 17 Feb 14
31/37