title: Comparison of mechanically ruled versus holographically varied line-spacing gratings for a soft-x-ray flat-field spectrograph.
abstract: Recent progress in the design of aspheric wave-front recording systems has permitted the manufacture of holographic gratings with highly variable groove densities that are suitable for flat-field spectrographs. A holographic grating thus recorded was processed to produce a laminar profile by use of reactive-ion etching. Measurements are reported of the absolute diffraction efficiency of this grating and of a comparable mechanically ruled grating. It is found that the holographic grating is much more effective in suppressing the higher orders. The spectral resolution was determined by use of a carbon Kalpha x-ray generator and a spectrograph with an imaging detector. The spectral resolution of the holographic grating was approximately 3 times worse than that of the ruled grating.
authors.affiliation: Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Institute, 25-1 Miiminami-machi, Neyagawa, 572-0019 Osaka, Japan. yamazaki@apr.jaeri.go.jp
authors.forename: T
authors.initials: T
authors.lastname: Yamazaki
authors.forename: E
authors.initials: E
authors.lastname: Gullikson
authors.forename: N
authors.initials: N
authors.lastname: Miyata
authors.forename: M
authors.initials: M
authors.lastname: Koike
authors.forename: Y
authors.initials: Y
authors.lastname: Harada
authors.forename: S
authors.initials: S
authors.lastname: Mrowka
authors.forename: U
authors.initials: U
authors.lastname: Kleineberg
authors.forename: J H
authors.initials: JH
authors.lastname: Underwood
authors.forename: M M
authors.initials: MM
authors.lastname: Yanagihara
authors.forename: K
authors.initials: K
authors.lastname: Sano