Numerical simulations of turbulent trapping in the weak beam-plasma instability

Technical Report · Thu Jun 05 04:00:00 EDT 1986

OSTI ID:5551038

Theilhaber, K; Laval, G; Pesme, D

Numerical simulations of the weak beam-plasma instability were done in the turbulent regime where small-scale trapping is a dominent feature of the instability, a regime with behavior not predicted by quasilinear theory. It occurs when the trapping frequency nu = (k/sup 2/D)/sup 1/3/ is larger than the growth rate ..gamma../sub k/ of the instability. The results of the simulations were compared with those of a specific model of the turbulence, the so-called ''turbulent trapping'' model, which gives precise formulas for the particle correlation functions, and predicts a growth rate well enhanced over the quasilinear value. It was found that the model gives accurate predictions for the correlation functions, and thus provides a good description of the turbulent structure of phase space. On the other hand, while growth rates were enhanced over the quasilinear values, the enhancements observed are smaller than expected from the quantitative predictions of the model. Further work is necessary to determine whether this discrepancy is a failing of the turbulent trapping model, or the result of the numerical limitations of our computational scheme.

• Research Organization: California Univ., Berkeley (USA). Electronics Research Lab.; Ecole Polytechnique, 91 - Palaiseau (France). Centre de Physique Theorique
• DOE Contract Number: FG03-86ER53220
• OSTI ID: 5551038
• Report Number(s): UCB/ERL-M-86/50; ON: DE86013047
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
BEAM-PLASMA SYSTEMS
INSTABILITY
NUMERICAL SOLUTION
PLASMA INSTABILITY
SIMULATION
TRAPPING
TURBULENCE