Application of magnetically-broadened hydrogenic line profiles to computational modeling of a plasma experiment

Magnetically-broadened hydrogenic line profiles are used, in conjunction wi th a non-local thermodynamic equilibrium (NLTE) code, to model an optically thick phenomenon in the Alcator C-Mod tokamak fusion experiment. The line profiles, including magnetic field effects as well as Doppler and Stark bro adening, have been calculated using Beline and are used in Cretin, a multi- dimensional NLTE radiation transfer code, to study the influence of a magne tic field on emergent spectrum. A midplane Alcator C-Mod multifaceted axisy mmetric radiation from the edge (MARFE), in which the magnetic field streng th was changed dynamically from 5.4 T down to 2.7 T, is simulated and compa red with experimental data. Assuming hydrodynamic and radiative equilibrium , MARFE simulations are performed in one-dimension with fixed plasma densit y and temperature profiles. Magnetic broadening effects on the brightness o f optically thick Lyman series lines are quantified. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.