Speaker
Dr
Dmitriy Skovorodin
(Budker INP SB RAS)
Description
In recent experiment on the GDT the longitudinal oscillations of plasma were observed [1]. The mode is discrete with frequency close to the bounce frequency of hot ions. It has typically zero angular wave-number and seems to be radially correlated. While the oscillation looks like sound-like standing wave it is well known that in plasma with hot ions the ion sound wave should be dumped strongly. However in case of GDT experiment the plasma has high beta and the distribution function of ions is far from equilibrium in contradistinction to usual assumptions of ion sound theory.
In present work kinetic approach is utilized to study the influence of the high beta on the dispersion of slow magnetic sound. It is shown that in plasma with sloshing ions the oscillating mode could exist even in limit of cold electrons if beta is high enough. The mode has sound-like frequency and is be unstable because the resonant interaction with ions. The threshold of the instability depends strongly on the distribution of ions.
[1]. Skovorodin D. I., Zaytsev K. V. and Beklemishev A. D., Phys. Plasmas, 20, 102123 (2013).
Primary author
Dr
Dmitriy Skovorodin
(Budker INP SB RAS)
Co-author
Dr
Alexei Beklemishev
(Budker INP SB RAS)