Abstract
The performance of a triggered vacuum spark source, emitting continuum radiation in the vacuum uv down to 80 Å, has been improved by adding a capillary made of insulating material and increasing the capacity of the condenser. A focusing system consisting of a toroidal mirror has been used in conjunction with the source and a grazing incidence spectrograph in the 500–80-Å spectral range. The results obtained indicate considerable gains (of the order of a factor of 200) with respect to previously used sources, allowing photographic recording of spectra with only one flash while maintaining good spectral resolution.