Charge-Exchange Recombination Spectroscopy Measurements of Ion Temperature and Plasma Rotation in PBX

摘要

The primary diagnostic on PBX for ion temperature measurements is charge-exchange recombination spectroscopy of low Z ions, wherein fast neutrals from the heating neutral beams excite spectral lines from highly excited states (n greater than or equal to 4) of hydrogenic 0, C, and He via charge-exchange collisions with the respective fully stripped ions. Since the neutral beams on PBX provide relatively low velocity neutrals (i.e., D sup 0 beams at 44 keV), the best signals are obtained using the near-uv lines of 0 sup 7+ (e.g., n = 8-7, 2976 A). Off-line analysis of the Doppler broadened and shifted line profiles includes non-linear least squares fitting to a model line profile, while a simplified on-line fast analysis code permits between-shot data analysis. (ERA citation 10:007989)