Variational calculation of alpha-driven bootstrap current in a deutrium–tritium tokamak reactor

Abstract

A general analytic expression for bootstrap current driven by fusion-born alpha particles is obtained in a deutrium–tritium tokamak plasma using a kinetic variational theory. A self-adjoint form of linearized Coulomb scattering operator has been used, which includes both energy and pitch angle collisions. The formula is applied to predict alpha-driven bootstrap current in a reactor condition similar to that of the International Thermonuclear Experimental Reactor Conceptual Design (ITER CDA) parameters [ITER Documentation Series, Number 18 (International Atomic Energy Agency, Vienna, 1991)]. The result agrees well with results obtained using another technique [Hsu et al., Phys. Fluids B 4, 4023 (1992)].

Trapped electron correction to beam driven current in general tokamak equilibria

“…10 In particular, in the limit of v e ӷu f the G factor is identical to l 31 , the dimensionless electron density gradient coefficient of the bootstrap current in the banana regime. For this particular bootstrap coefficient, an accurate analytic expression exists, 11 which is applicable to low-and high-␤ equilibria in general tokamak geometry.…”