Adiabatic Invariant and Evaluation of Particle Loss in Helical Torus

Abstract

Analytic expression for the longitudinal adiabatic invariant is derived for general magnetic configuration. The orbit loss is evaluated to determine the outermost loss-free surface. Geometrical factor of the neoclassical transport coefficients in 1/ν regime in helical torus is calculated by using the longitudinal adiabatic invariant. The dependence of the particle confinement upon the geometrical parameter is investigated; and the improvement by the inward shift of the plasma is quantitatively clarified.