Mp. Kowalski et al., DUAL-WAVEBAND OPERATION OF A MULTILAYER-COATED DIFFRACTION GRATING INTHE SOFT-X-RAY RANGE AT NEAR-NORMAL INCIDENCE, Applied optics, 32(13), 1993, pp. 2422-2425
A concave diffraction grating (2400 grooves/mm) coated with a Si/Mo mu
ltilayer has an efficiency of 2.5% at 290 angstrom and a resolving pow
er of 14,000 in third order of 156 angstrom.