Long-time simulation of the single-mode bump-on-tail instability

Technical Report · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7108785

Simon, A; Radin, S; Short, R W

A Vlasov code was modified and used to study long-time behavior of the single-mode bump-on-tail instability. Large oscillations which interrupted his original runs at ..omega../sub 0/T approx. 1300 were identified and controlled by heating of the cold background electrons. A run to ..omega../sub 0/T = 30,000 showed saturation at about the level predicted by Simon and Rosenbluth, before oscillations set in. A run with warmer background electrons was again interrupted by oscillations. A weakly unstable case was followed to ..omega../sub 0/T = 60,000 and saturated at much lower amplitude. In all cases, the velocity distribution developed strong ripples near v = 0. These are shown to be due to a numerical grid effect, and may be responsible for the oscillations and for the low level of saturation in the weakly unstable case. 7 refs., 30 figs., 2 tabs.

• Research Organization: Rochester Univ., NY (USA). Lab. for Laser Energetics
• DOE Contract Number: FC08-85DP40200
• OSTI ID: 7108785
• Report Number(s): DOE/DP/40200-67; ON: DE88008441
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
BUMP-IN-TAIL INSTABILITY
COLLISIONLESS PLASMA
ELECTRIC FIELDS
INSTABILITY
NONLINEAR PROBLEMS
OSCILLATIONS
PLASMA
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA SIMULATION
SIMULATION