Soft x-ray monochromator with a varied-space plane grating for synchrotron radiation: design and evaluation

A soft x-ray monochromator was developed for synchrotron radiation and installed at the Photon Factory in the National Laboratory for High Energy Physics. This monochromator consists of only two optical elements: a plane mirror and a varied-space plane grating with focusing properties. The 0.7-10-nm wavelength range can be covered with resolutions of 640 at 1.4 nm and 1200 at 5 nm. The output photon flux at wavelengths above 1 nm is ~10(10)-10(11) photons/s for a 100-mA beam current in the 1% spectral bandwidth.