Spontaneous multi-keV electron generation in a low-RF-power axisymmetric mirror machine

Dataset · Wed May 01 00:00:00 EDT 2019

DOI:https://doi.org/10.11578/1562006· OSTI ID:1562006

Swanson, C; Cohen, S A

Title:Spontaneous multi-keV electron generation in a low-RF-power axisymmetric mirror machineAbstract: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.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: U. S. Department of Energy
• OSTI ID: 1562006
• Country of Publication: United States
• Language: English