ZHOU Hong-jun, ZHONG Peng-fei, ZHENG Jin-jin, et al. Quantitative research on higher order harmonic suppression in 17~33 nm with different thickness Al filters[J]. Optics and precision engineering, 2007, 15(7): 1016-1020.
ZHOU Hong-jun, ZHONG Peng-fei, ZHENG Jin-jin, et al. Quantitative research on higher order harmonic suppression in 17~33 nm with different thickness Al filters[J]. Optics and precision engineering, 2007, 15(7): 1016-1020.DOI:
With 840 l/mm transmission grating (made in house) behind the exit of Spherical Grating Monochromator (SGM) in Spectral Radiation Standard and Metrology (U27) beamline
the dispersion of exit beam and the contributions of different orders were analyzed. The results of higher order harmonics suppression by different thickness Al filters were given in the region of 17~33 nm. The results show that when the thickness of Al filter is 400 nm
and the wavelength between 17~33 nm
the contributions of higher orders to the detector signal are restricted to less than 2%
and the Photon Diode (PD) intensity is strong enough. After being corrected by quantum efficiency of the PD detector
the higher order contributions are less than 0.6%
which is important for calibration absolute reflectivities of multilayer and detector.