High-resolution laboratory reflectometer for the study of x-ray optical elements in the soft and extreme ultraviolet wavelength ranges
С. А. Гарахин, Н. И. Чхало, I. A. Kas’kov, A. Ya. Lopatin, И. В. Малышев, A. N. Nechay, А. Е. Пестов, В. Н. Полковников, Н. Н. Салащенко, М. В. Свечников, Н. Н. Цыбин, I. G. Zabrodin, S. Yu. Zuev
Abstract
A high-resolution laboratory reflectometer designed for operation in the soft x-ray (SXR) and extreme ultraviolet (EUV) ranges is described. High spectral resolution, up to 0.028 nm, in a wide spectral range is achieved due to the Czerny-Turner monochromator. A laser plasma generated by irradiating a solid-state target with a focused laser beam (wavelength 1.06 µm, pulse energy 0.5 J, duration 4 ns, and pulse repetition rate 10 Hz) is used as a source of SXR and EUV radiation. The goniometer allows the study of curved optical elements with an aperture up to NA = 0.5 and a diameter of up to 500 mm. The methods providing high efficiency of the optical system and spectral resolution in a wide range of wavelengths are described in detail. The problem of taking into account high orders in the recorded spectra of a laser plasma is discussed. A comparison of the measurement results with the described reflectometer and the optics beamline at the BESSY-II synchrotron is given.