Spontaneous multi-keV electron generation from Fermi acceleration and magnetic moment non-adiabaticity
Abstract
X-ray emission shows the existence of multi-keV electrons in low-temperature, low-power, capacitively-coupled RF-heated magnetic-mirror plasmas that also contain a warm (300 eV) minority electron population. Though these warm electrons are initially passing particles, we suggest that collisionless scattering - mu non-conservation in the static vacuum field - is responsible for a minority of them to persist in the mirror cell for thousands of transits during which time a fraction are energized to a characteristic temperature of 3 keV, with some electrons reaching energies above 30 keV. A heuristic model of the heating by a Fermi-acceleration-like mechanism is presented, with mu non-conservation in the static vacuum field as an essential feature.
Keywords
Cite
@article{arxiv.1901.10901,
title = {Spontaneous multi-keV electron generation from Fermi acceleration and magnetic moment non-adiabaticity},
author = {C. Swanson and S. A. Cohen},
journal= {arXiv preprint arXiv:1901.10901},
year = {2019}
}
Comments
6 pages, 7 figures