High intensity hot filament vacuum ultraviolet light source

We describe a simple modification of a McPherson-Hinteregger-type capillary discharge lamp which converts it from a cold cathode discharge to a hot filament discharge. This results in about a 10-fold intensity increase in the 7-12 eV photon energy range and about a fourfold increase in operating time between cleanings. The spectral output power is presented. © 1970 The American Institute of Physics.