Characterization of imaging normal-incidence multilayer mirrors for the 40- to 300-A range by spectroscopic techniques using a laser-plasma radiation source

摘要

A number of high-performance normal-incidence multilayer mirrors (MMs) have been fabricated on concave (r $EQ 1.6 - 2.0 m) fused silica substrates using laser deposition and a magnetron ion sputtering source. The resonance wavelengths $lambda$-0$/ $EQ 2nd of the MMs synthesized are proximate to 45, 130, 175, 190, and 304 angstroms. The MMs have been subjected to scrutiny by a spectroscopic technique employing a laser-plasma broadband XUV radiation source. The spectral shapes of the resonance reflection curves, the $lambda$- 0$/ values, and the aperture uniformity (topography) of the mirrors have been determined spectroscopically. Normal-incidence reflection maxima, which correspond to higher-order reflection (k$lambda $EQ 2n$-$lambda$/d, k $GRT 1), have been observed for all of the Mo-Si MMs with $lambda $GREQ 175 angstroms.