Moment approach to the bootstrap current in nonaxisymmetric toroidal plasmas using deltaf Monte Carlo methods

To evaluate the bootstrap current in nonaxisymmetric toroidal plasmas quantitatively, a deltaf Monte Carlo method is incorporated into the moment approach. From the drift-kinetic equation with the pitch-angle scattering collision operator, the bootstrap current and neoclassical conductivity coefficients are calculated. The neoclassical viscosity is evaluated from these two monoenergetic transport coefficients. Numerical results obtained by the deltaf Monte Carlo method for a model heliotron are in reasonable agreement with asymptotic formulae and with the results obtained by the variational principle.