Stochastic energy diffusion of electrons in a plasma by an electron cyclotron wave

Journal Article · Fri Jan 01 00:00:00 EST 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860857· OSTI ID:7118378

Farina, D ^[1]; Pozzoli, R; Mennella, A; Ronzio, D ^[2]

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1. Istituto di Fisica del Plasma, Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, via Bassini 15, I-20133 Milano (Italy)
2. Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy)

The investigation of the energy diffusion process of the electrons in a magnetized plasma due to an electron cyclotron wave in perpendicular propagation with respect to the magnetic field is performed. Starting from the description of the relativistic electron motion by means of an action-angle Hamiltonian [ital H]([ital I],[theta],[ital t]), the Fokker--Planck--Kolmogorov (FPK) approach to the diffusion is considered for a globally stochastic regime of the system. In this regime, the phase correlation process is analyzed, and the characteristic decay time is estimated analytically. The action diffusion coefficient [ital D]([ital I]) is derived and compared with a local quasilinear expression. With explicit reference to the low-density regime, where [ital D] increases with [ital I], and is very close to the quasilinear coefficient, the solution of the diffusion equation is compared with the results obtained by direct numerical integration of the motion equations for a statistically significant ensemble of particles. A good agreement with the local quasilinear FPK diffusion is observed. In addition, when the amplitude of the perturbation is varied, oscillations of the average action values around the quasilinear results are found on the long time scale.

• OSTI ID: 7118378
• Journal Information: Physics of Fluids B; (United States), Vol. 5:1; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON CYCLOTRON-RESONANCE
DIFFUSION
STOCHASTIC PROCESSES
FOKKER-PLANCK EQUATION
NUMERICAL SOLUTION
PLASMA HEATING
RELATIVISTIC BEAM INJECTION
BEAM INJECTION
CYCLOTRON RESONANCE
DIFFERENTIAL EQUATIONS
EQUATIONS
HEATING
PARTIAL DIFFERENTIAL EQUATIONS
RESONANCE
700350* - Plasma Production
Heating
Current Drive
& Interactions- (1992-)