Abstract
In this paper, the focusing performance of an ellipsoidal neutron focusing mirror is evaluated by using neutron beams generated from CN3 beam port at Kyoto University Research Reactor (KUR-CN3). KUR-CN3 can generate a wavelength of neutrons from 0 to 10 Å, with a peak intensity at wavelength of 2.7 Å. To well focus the neutron beams, an aperture and slit are fabricated by using Cadmium. The aperture, which dominates the size of incident beam, is set to 1 mm in diameter by considering the intensity of cold neutrons. The U-shape slit. is designed by following the shape of incident beam to the mirror, and is used to shield the unnecessary beams. For collecting the data, a Register network Photo Multiplying Tube type detector (RPMT) which is capable of doing pulse neutron spectrometry with 2D Position sensitive and counting mode is adopted. The results show that the neutron beams are well focused by the mirror. The focusing spot size at FWHM is 1.050 mm and 1.047 mm in vertical and horizontal direction, which is almost equivalent to the size of aperture. From the 3D view of focused neutron beam, no significant diffuse scattering can be found.
