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

Koike, Masato; Sano, Kazuo*; Harada, Yoshihisa*; Yoda, Osamu; Ishino, Masahiko; Tamura, Keisuke*; Yamashita, Kojun*; Moriya, Naoji*; Sasai, Hiroyuki*; Jinno, Masafumi*; Namioka, Takeshi*

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, we have designed and constructed a new type of monochromator that combined two types of Monk-Gillieson monochromators. One is a conventional type equipped with three varied-line-spacing plane gratings, allowing a choice of two included 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 monochromator is operated in the SNR and conventional modes over the ranges of 0.7-2.0 nm and 2.0-25 nm, respectively. In this paper we describe the optical and mechanical designs of the monochromator, wavelength calibrations in the SNR mode, and preliminary experimental data, such as the transmittance of an Al filter at 0.8 nm and the total yield photoelectron measurement on a MgO powder in a wavelength rage of 0.7-2 nm.