Kerr-Cell-Shuttered f/1.5 Stigmatic Spectrograph for Nanosecond Exposures

This paper describes a specially designed high-speed spectrograph that routinely provides information on the spatial distribution of the electron density of the gas flow in a high-performance shock tube. The instrument has a measured resolution of 1.5 A, a camera of f/1.5 aperture, and records the 3900-6700-A spectral region in a single 200 nsec exposure. Special features of the instrument include Kovar spacing plates for temperature compensation, orthogonal grating adjustments for quick alinement, a split-image view finder for focusing, and modular construction to allow different cameras and gratings to be vised. Spatially resolved spectra, obtained with this instrument, of 15-km/sec shock waves traveling in air are presented.