New Detector for the Vacuum Ultraviolet

Abstract

A new method is described for detecting vacuum uv radiation. This radiation is converted to visible light in two steps, the first being creation of photoelectrons at a high voltage cathode, the second consisting of stopping these electrons in a scintillator at ground potential. The visible scintillations are detected with a standard photomultiplier. The system has been compared with a sodium salicylate detector, using a vacuum uv monochromator and a steady light source. Spectral lines between 500 and 1300 Å have readily been recorded. Compared to other systems, the new detector offers a number of advantages which are discussed. Preliminary results for pulsed light sources indicate that the method is also useful for studying phenomena whose time scales are of the order of 1 μsec.