Internal-Grating Electronographic Spectrographs for the Far Ultraviolet and X-Ray Wavelength Ranges,
Abstract
Described are concave-grating spectrographs, of the normal-incidence and grazing-incidence types, using electronographic recording with a front-surface alkali-halide photocathode on the Rowland circle. The normal-incidence version uses magnetic focusing, with unity magnification, and is useful at wavelengths above 300-400 A. The grazing-incidence version is being developed in two types; one uses magnetic focusing and near-unity magnification, and is intended for applications where high resolution is required but the available flux is relatively high; the other uses electrostatic focusing and a large demagnification ratio and is intended for applications where resolution can be sacrificed to obtain higher sensitivity for weak sources (such as celestial X-ray sources). The use of grazing incidence results in a higher quantum yield from the photocathode, as well as a higher reflectance from the grating, in the extreme ultraviolet and soft X-ray wavelength ranges. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 16, 1971
- Accession Number
- ADA083551
Entities
People
- George R. Carruthers
Organizations
- United States Naval Research Laboratory