Non-ambipolar Transport by Trapped Particles in Tokamaks

Park, J.K. . Boozer, A.H and . Menard, J.E

Princeton University. Plasma Physics Laboratory.

关键词: Precession;    Magnetic Fields;    70 Plasma Physics And Fusion Technology;    Sensitivity;    Diffusion, Magnetic Field, Transport Theory, Tokamaks;   

RP-ID  :  PPPL-4375
RP-ID  :  DE-AC02-09CH11466
RP-ID  :  950505

美国|英语

来源: UNT Digital Library

【 摘 要 】

Small non-axisymmetric perturbations of the magnetic field can greatly change the performance of tokamaks through non-ambipolar transport. A number of theories have been developed, but the predictions were not consistent with experimental observations in tokamaks. This Letter provides a resolution, with a generalized analytic treatment of the non-ambipolar transport. It is shown that the discrepancy between theory and experiment can be greatly reduced by two effects: (1) The small fraction of trapped particles for which the bounce and precession rates resonate. (2) The non- axisymmetric variation in the field strength along the perturbed magnetic field lines rather than along the unperturbed magnetic field lines. The expected sensitivity of ITER to non-axisymmetries is also discussed.