Slit Curvature in Grating Monochromators Employing Single or Multiple Diffraction

Abstract

The curvatures required for the entrance and exit slits of a grating monochromator and the wavelength errors at the ends of incorrectly curved slits are considered for cases of single and multiple traversal of the grating. Under certain conditions, a fixed curvature will provide zero error at slit ends for all wavelengths. In other cases, slits of fixed curvature can have correct shape for only one orientation of the grating. The best choice of this orientation is determined, and the range of angles over which the grating can be used is indicated.