Development of a focusing supermirror for GISANS measurement at the reflectometer BL17

Yamazaki, Dai   ; Maruyama, Ryuji   ; Aoki, Hiroyuki  ; Soyama, Kazuhiko  ; Hanashima, Takayasu*; Akutsu, Kazuhiro*; Miyata, Noboru*

Grazing-Incidence Small Angle Neutron Scattering (GISANS) is a powerful tool to investigate in-plane structure at surfaces or interfaces. But in the measurement neutron beam focusing is essential even at a high-intensity neutron facility such as J-PARC MLF. It is because the incident beam should be collimated so that it is small in size (e.g., 1 mm in diameter) at the detector position and the beam intensity therefore is greatly impaired. We have developed high performance neutron supermirrors with ion beam sputtering and applied them to focusing supermirrors. In this contribution, reported is a development and fabrication of a focusing supermirror for GISANS measurements at the neutron reflectometer BL17 (Sharaku) of J-PARC MLF. The mirror is an elliptically shaped NiC/Ti supermirror (m=4) of 400 mm in length coated on fused quartz substrate. A performance test showed intensity gain of 20 compared with an optimum beam collimation by slits.