PLASMA EXHAUST REQUIREMENT FOR SUSTAINED IGNITION: RELAXATION DUE TO PROFILE CONSIDERATIONS

摘要

The problem of helium ash removal from a fusion reactor is treated with spatially varying plasma parameters, and the allowance of variations is found to strongly influence the necessary conditions for sustained deuterium-tritium (DT) ignition. In particular, a one dimensional (1-D) particle transport model is used to calculate the core helium concentration on the basis of a suitably parametrized source profile. It is estimated that the necessary exhaust efficiency for sustained DT ignition is of the order of 2/100, rather than the familiar 10/100 figure deduced from uniform plasma calculations.