Nuclear reaction rates and energy in stellar plasmas: The effect of highly damped modes

Abstract

The effects of the highly damped modes in the energy and reaction rates in a plasma are discussed. These modes, with wavenumbers k ≫ k D , even being only weakly excited, with less than k B T per mode, make a significant contribution to the energy and screening in a plasma. When the de Broglie wavelength is much less than the distance of closest approach of thermal electrons, a classical analysis of the plasma can be made. It is assumed, in the classical analysis, withh → 0, that the energy of the fluctuationshω ≪ k B T .Using the fluctuation-dissipation theorem, the spectra of fluctuations with h = 0 is appreciably decreased. The decrease is mainly for the highly damped modes at high frequencies (∼ 0.5 − 3k B T ). Reaction rates are enhanced in a plasma due to the screening of the reacting ions. This is taken into account by the Salpeter factor, which assumes slow motion for the ions. The implication of including the highly damped modes (withh = 0) in the nuclear reaction rates in a plasma is discussed. Finally, the investigations presently done on these effects in particle simulations with the sheet model and the multiparticle quantum simulation code are described.

Variational approach for the quantum Zakharov system

“…Quantum plasmas have received much attention in recent times, especially because of the ongoing miniaturization of ultrasmall electronic devices and micromechanical systems [1] and to the relevance of quantum effects for intense laser-plasmas [2] and for dense astrophysical objects [3]. Frequently, the de Broglie wavelength of the charge carriers (electrons, positrons, holes) of these systems is comparable to the characteristic dimensions of the system, making a quantum treatment unavoidable.…”

Modulational interactions in quantum plasmas

“…Recently, there has been increasing interest in quantum plasmas due to their relevance to modern laser-matter interaction experiments (e.g., the compressed hydrogen in the fast ignition scenario of inertial fusion is in a quantum plasma state), as well as their ubiquity in different astrophysical and cosmological systems [11][12][13] (e.g., interstellar or molecular clouds, planetary rings, comets, interiors of white dwarf stars, etc. ), in nanostructures [14], and in microelectronic devices [15].…”

Nonlinear ion-acoustic solitons in a magnetized quantum plasma with arbitrary degeneracy of electrons

“…The study of ion-acoustic waves has also gained importance in quantum plasmas for understanding electrostatic wave propagation in microscopic scales. During the last decade, there has been renewed interest in study of the collective wave phenomenon in quantum plasma, motivated by applications in semiconductors [1], high-intensity laser-plasma experiments [2][3][4], and highdensity astrophysical plasmas such as in the interior of massive planets and white dwarfs, neutron stars, or magnetars [5][6][7]. Quantum or degeneracy effects appear in plasmas when the de Broglie wavelength associated with the charged carriers becomes of the order of the interparticle distances.…”