Effect of diffusion pump oil contamination on diffraction grating efficiency in the VUV spectral region.
The efficiency of a concave grating contaminated with diffusion pump oil has been measured and compared with that of an uncontaminated sister grating. At 1216 A and 4000 A, the contamination has little effect on the efficiency, but at intermediate wavelengths the loss in efficiency is large. Vapor degreasing provided a partial restoration, and overcoating with gold, a complete restoration of efficiency.
Hunter
W R
WR
Angel
D W
DW