A imaging spectrometer for the vacuum ultraviolet (VUV) measures vertical spatial profile, in addition to dispersed wavelengths, to view plasma impurity emission lines from 300 to 3200 ？. Using an entrance slit width of 0.02 mm, users can achieve 15.3 pm spectral resolution FWHM. New spectrometers can be built for high vacuum (10-6 Torr) and ultra-high vacuum (10-10 Torr).

(From:https://www.laserfocusworld.com/articles/2018/03/imaging-spectrometer-for-vuv-from-mcpherson-measures-vertical-spatial-profile.html)