Side-viewing detector for a vacuum ultraviolet reflectometer.

The problem of detector response, which arises in the application of the reflectance vs angle of incidence method to the determination of optical constants in the vacuum UV spectral region is discussed. The analysis is performed for the side-viewing 1P21 detector sensitized with sodium salycilate. To take advantage of the wide selection photomultipliers available in the end-on configuration, a scheme for converting the end-on types to a side viewing geometry with a response uniform over several degrees of detector rotation is developed. It consists of a 32-mm diam spherical collector, located at the end of a cylindrical photomultiplier holder, with 12-mm entrance and viewing ports and a position for the sensitized screen also 12-mm in diameter.-