Collisional losses of fast particles in low current axisymmetric tokamaks

Journal Article · Mon May 01 04:00:00 EDT 1995 · Fusion Technology

OSTI ID:121570

Goloborod`ko, V Y; Lutsenko, V V; Reznik, S N; Yavorskij, V A ^[1]

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1. Inst. for Nuclear Research, Kiev (Ukraine)

Three-dimensional Fokker-Planck simulation of collisional losses of mega-electron-volt fusion products in axisymmetric tokamaks with plasma currents I < 2 MA is carried out. The calculations take into account both loss due to radial diffusion and loss caused by pitch-angle scattering in the first-orbit loss region in velocity space. Collisional losses of deuterium-deuterium (D-D) fusion products in the energy range 0.5 < {epsilon}/{epsilon}{sub 0} < I (where {epsilon}{sub 0} is the birth energy) are found to be increased with plasma current and comparable to a first-orbit loss at I > 1.5 MA. The loss mechanism considered may be responsible for the observed experimentally delayed losses of D-D fusion products in the Tokamak Fusion Test Reactor (TFTR). The dependencies of collisional losses on plasma current, effective charge number of the plasma (Z{sub eff}), and aspect ratio are investigated. The distributions of escaped ions over pitch angles, energies, and poloidal angles are evaluated. The fraction of collisionally lost fast fusion products is shown to scale like (v{sub $$PRP}/v{sub s}){sup 0.6} or Z{sub eff}{sup 0.6} (here v{sub $$PRP} and v{sub s} are characteristic collision rates of pitch-angle scattering and slowing down, respectively). The approach used may be considered as an alternative to the approach based on Monte Carlo modeling of scattering and can serve as a validity check of the latter. 12 refs., 5 figs.

• OSTI ID: 121570
• Journal Information: Fusion Technology, Journal Name: Fusion Technology Journal Issue: 3 Vol. 27; ISSN 0748-1896; ISSN FUSTE8
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
99 GENERAL AND MISCELLANEOUS
ASPECT RATIO
AXIAL SYMMETRY
D-D REACTORS
DIFFUSION
FAST NEUTRONS
FOKKER-PLANCK EQUATION
LOSSES
MONTE CARLO METHOD
SIMULATION
TFTR TOKAMAK
TOKAMAK DEVICES