ON-BLAZE OPERATION OF A MO SI MULTILAYER-COATED, CONCAVE DIFFRACTION GRATING IN THE 136-142-(A)CAP WAVELENGTH REGION AND NEAR NORMAL INCIDENCE/

The efficiency and resolving power of a concave, 2400-groove/mm, blaze d diffraction grating that had a Mo/Si multilayer coating were determi ned. The multilayer coating had a peak reflectance of 55% at 140-angst rom near normal incidence. The efficiency of the multilayer grating fo r wavelengths in the 136-139-angstrom range was 2% near normal inciden ce. This efficiency was a factor of 150 greater than the efficiency of a sister replica Au-coated grating in the same wavelength region. The resolving power of the multilayer-coated grating in the third order o f a V VIII transition with a first-order wavelength of 140.451 angstro m was 9100. Comparisons with the Au-coated grating indicated that the application of the multilayer coating did not affect the resolving pow er or the blaze angle.