Performances of oscillating radial collimator for the Fermi chopper spectrometer 4SEASONS at J-PARC

Abstract A novel operation pattern is introduced into the oscillating radial collimator for the Fermi chopper spectrometer 4SEASONS at the Materials and Life Science Experimental Facility in J-PARC. This pattern is shown to suppress shadows originating from shielding blades of the radial collimator. We also report the transmission property of the oscillating radial collimator for 4SEASONS, based on an investigation of the scattered intensities from polycrystalline samples of different diameter.