New type of Monk-Gillieson monochromator capable of covering a 0.7- to 25-nm range

A new type of monochromators that incorporates two kinds of Monk-Gillieson monochromators has been designed and constructed for the purpose of realizing an evaluation beamline for characterizing soft X-ray optical elements in a wide wavelength range of 0.7-25 nm. One of the monochromators is a conventional type equipped with three varied-line-spacing plane gratings, allowing a choice of two inclusion angles. The other is a new type that employs a scanning mechanism based on Surface Normal Rotation (SNR). The SNR scheme provides high throughput at short wavelengths and simple scanning mechanism by means of a grating rotation about its normal. The monochromators is operated in the SNR and conventional modes over the ranges of 0.7-2.0 nm and 2.0-25 nm, respectively. The system was installed on a beamline of the AURORA, a superconducting compact storage ring, at the Synchrotron Radiation Center, Ritsumeikan University. In this paper we describe the optical and mechanical designs of the monochromators, and a practical method of wavelength calibration. Also experimental data are shown which demonstrate the performance and versatility of the new type of Monk-Gillieson monochromators.