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

Nakamura, Mitsutaka   ; Kambara, Wataru*; Iida, Kazuki*; Kajimoto, Ryoichi  ; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Ishikado, Motoyuki*; Aoyama, Kazuhiro*

Recently there has been an increasing need for inelastic neutron scattering experiments under some special environments such as magnetic fields, pressure and high temperatures. In order to obtain high quality data, the unnecessary scattering caused by sample environmental apparatus should be suppressed as much as possible. We have developed an oscillating radial collimator with a view to satisfying users' needs, which is specialized for the Fermi chopper spectrometer 4SEASONS at J-PARC.4SEASONS provides relatively high incident energies, and thus we chose hydrogen free metal sheets as the collimator blades. The control system of this oscillating radial collimator enables us to flexibly tune the oscillating pattern, such as the oscillating speed and oscillating angle. In this presentation, we report the performances and remaining issues of the newly developed oscillating radial collimator for 4SEASONS.