Non-local transport in a tokamak plasma divertor with recycling
- Princeton Univ., NJ (United States). Plasma Physics Lab.
- Institut National de la Recherche Scientifique-Energie et Materiaux, Varennes, PQ (Canada)
The plasma transport, particle and energy fluxes, near the diverter plate with high recycling has been modeled by using an electron kinetic code (Fokker-Planck International) in conjunction with a two-fluid ambipolar code. We include the effects of ionization and excitation of the hydrogen atoms. The electron energy distribution calculated from the kinetic code shows a large deviation from Maxwellian especially near the plate. This deviation from Maxwellian is due to the non-local transport of the suprathermal electrons from the SOL, and due also to the absorption of the fast electrons by the target plate. The heat flux near the plate is shown to be nonlocal, in that it is not determined uniquely by the local plasma parameters. Therefore the classical transport coefficients in the fluid model must be modified by including a nonlocal effect to produce the kinetic results. The kinetic calculation is compared with those of the fluid code with different values of the electron heat flux limiter factor (f). To reduce the computer load, the initial condition we used corresponds to the equilibrium solution already found with the fluid code with f=0.2. The fluid and Fokker-Planck codes are relaxed until all transients associated with electron dynamics have disappeared. In section 2, we present the kinetic code. The fluid code is presented in section 3. The boundary conditions used in these simulations are given in section 4. Finally the results and conclusion of these simulations are presented in section 5.
- Research Organization:
- Princeton Univ., NJ (United States). Plasma Physics Lab.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 10189031
- Report Number(s):
- PPPL-CFP-2964; CONF-931070-3; ON: DE94001497; TRN: 93:023079
- Resource Relation:
- Conference: 4. international workshop on plasma edge theory (PET) in fusion devices,Varenna (Italy),4-6 Oct 1993; Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
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