Modeling of Neutral Hydrogen Velocities in Tokamak Fusion Test Reactor

November 1, 1996

Phys. of Plasmas, 3(11), 4084-4094 (1996).

Stotler, D. P., Skinner, C. H., Budny, R. U., Ramsey, A. T., Ruzic, D. N., Turkot Jr., R. B.

Monte Carlo neutral transport simulations of hydrogen velocities in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] are compared with experiment using the Doppler-broadened Balmer-alpha spectral line profile. Good agreement is obtained under a range of conditions, validating the treatment of charge exchange, molecular dissociation, surface reflection, and sputtering in the neutral gas code DEGAS [D. Heifetz et al., J. Comput. Phys. 46, 309 (1982)]. A residual deficiency of 10–100 eV neutrals in most of the simulations indicates that further study of the energetics of H<sup> + </sup><sub>2</sub> dissociation for electron energies in excess of 100 eV is needed.