Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
The neutral density and particle source rate have been measured experimentally in the Helically Symmetric eXperiment (HSX) using an absolutely calibrated set of 15 Ha detectors. Nine of the Ha detectors make up a poloidal array at one toroidal location, with the other six distributed toroidally around the device. The neutral distribution has been modeled using the Monte Carlo code DEGAS1. 3-D simulations have been normalized to the Ha brightness at the central chord of the poloidal array. The calculations show good agreement in the line-integrated profiles from the Ha arrays when the gas puff is located at the same toroidal plane as the poloidal array. The toroidal Ha array reveals a significant asymmetry in the emission, with the brightness at the gas puff a factor of five greater than the signal on the other side of the torus. Results of simulations of different operating regimes will be presented [1] Heifetz, D.B. et. al., J. Comp. Phys. 46, (1982) 309