1. Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer
- Author
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Kowalski, Michael P., Barbee, Troy W. Jr., Heidemann, Klaus F., Gursky, Herbert, Rife, Jack C., Hunter, William R., Fritz, Gilbert G., and Cruddace, raymong G.
- Subjects
Diffraction gratings -- Research ,Holography -- Research ,Rockets, Sounding -- Usage ,Optical spectrometers -- Design and construction ,Astronomy ,Physics - Abstract
We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 Angstroms rms after coating. Using synchrotron radiation, we completed an efficiency calibration map over the wavelength range 225-245 Angstroms. At an angle of incidence of 5 degrees and a wavelength of 234 Angstroms, the average efficiency in the first inside order is 10.4 +/- 0.5%, and the derived groove efficiency is 34.8 +/- 1.6%. These values exceed all previously published results for a high-density grating.
- Published
- 1999