A Rapid Scan Spectrograph for Plasma Spectroscopy

Abstract

An ultrarapid scanning spectrograph, having a spectral scan speed of from 10 to 200 Å/μsec and a scanning range of 210 Å, is described. This spectrograph was employed to obtain time-resolved H_α, H_β, and H_γ line profiles, and line-to-continuum ratios, in a shock-heated hydrogen plasma. Electron densities were determined at various times behind the shock front from the Stark-broadened lines and the plasma temperature was obtained from the line-to-continuum ratio. The electron densities obtained from the three lines were found to compare remarkably well. In addition, it was possible to utilize the Saha equation and correlate the time-behavior of the electron density with the temperature and atom density measurements.