Comparison of mechanically ruled versus holographically varied line-spacing gratings for a soft-x-ray flat-field spectrograph.
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.
Yamazaki
T
T
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
Gullikson
E
E
Miyata
N
N
Koike
M
M
Harada
Y
Y
Mrowka
S
S
Kleineberg
U
U
Underwood
J H
JH
Yanagihara
M M
MM
Sano
K
K