Fast high resolution echelle spectroscopy of a laboratory plasma

An echelle diffraction grating and a multianode photomultiplier tube are paired to construct a high resolution R= / 2.5 104 spectrograph with fast time response for use from the UV through the visible. This instrument has analyzed the line shape of C III impurity ion emission at 229.687 nm over the lifetime 100 s of the hydrogen plasmas produced at SSX. The ion temperature and line of sight average velocity are inferred from the observed thermal broadening and Doppler shift of the line. The time resolution of these measurements is about 1 s, sufficient to observe the fastest magnetohydrodynamic activity. © 2006 American Institute of Physics. DOI: 10.1063/1.2212405