A HIGH-FLUX 3-M NORMAL INCIDENCE MONOCHROMATOR AT BEAMLINE-20A OF THE PHOTON FACTORY

A high-flux 3-m normal incidence monochromator (3-m NIM) has been installed at beam line 20A of the Photon Factory. The 3-m NIM can supply a high photon flux in the wavelength region 30-200 nm, primarily because of a large horizontal acceptance angle of 28 mrad for the synchrotron radiation (SR) beam from bending magnet 20. The photon flux of the 3-m NIM was estimated to be ≈1012 photons/s with Δλ≈0.1 nm at ≈50 nm by measuring the photoemission current from a gold-coated surface. The resolving power with a 2400 grooves/mm grating was found to be greater than 25000 at 90 nm from the autoionization profile of the Xe nd' states converging to Xe + 2P1/2. © 1995 American Institute of Physics.