実験報告書様式（一般利用課題・成果公開利用）（ ※本報告書は英語で記述してください。ただし、産業利用課題として採択されている方は日本語で記述していただいても結構です。 ）MLF Experimental Report

提出日 Date of Report

課題番号 Project No.

装置責任者 Name of responsible person

2010B0079

Fujio Maekawa

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Neutron Beam Focusing using supermirrors coated on precisely

BL10

figured surfaces

実施日 Date of Experiment

実験責任者名 Name of principal investigator

10/11/30-10/12/02

Dai Yamazaki
所属 Affiliation
J-PARC Center
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
No sample.

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

We examined the focusing performance of a 1-dimensional elliptic supermirror fabricated for multichannel
focusing-supermirror stack. The mirror is an m=3 NiC/Ti supermirror deposited with an ion-beam sputteringmachine of JAEA on a quarts substrate of 1.5mm in thickness which was elliptically shaped with anultra-precise surface figuring technique (numerically- controlled local wet etching (NC-LWE))
Figure1 shows the beamline buildon the experimental bench of BL10. A
manual slit and an imaging plate (IP)was placed at the two focal points ofellipsoid on which the mirror wasdesigned. The mirror was installed at
the middle point of the slit and IP andFig.1 Beam line built at the BL10 instrument room..

accept neutrons at incident angle of
0.83 deg, which corresponds to critical

12. 実験方法及び結果（つづき） Experimental method and results (continued)
angle for 2.79 Å. Additionally, we installed a flat supermirror just after the manual slit in order to deflect thebeam out of the high-energy direct beam region and reduce background. In this experiment, both the focusing
supermirror and the flat mirror were placed almost horizontally and reflected neutron beam upward.

Fig.2 (a)2-dimensional profile of the focused beam. (b) that of the unfocused beam. (c) Vertical slicesof profiles (a) and (b) at the horizontal center. Initial slit width was set at 0.10mm

Figure2 shows images of the focused and unfocused beam with the slit width (the initial spot size) 0.10mm.
They were taken by a same IP for 1200 seconds. The 2-dimensional data was retrieved from the IP by the IP
scanner BAS2500 owned by BL10 with following parameters: dynamic range: L=5, Sensitivity S=104, pixel size
= 50μm. The focusing mirror successfully focused the beam into 0.244mm, which was also confirmed by aknife-edge scan shown in Fig..3. Deviation from ideal focusing size 0.10 mm might be attributed to some
distortion of the mirror and misalignment. Peak intensity gain was about 5.5, which is smaller than the value
more than 10 by the previous experiment performed at CHOP, JRR-3.
Figure4 compares wavelength distributions of focused and unfocused beams. The uprising of intensity
around 2.7 Å corresponds to critical angle of the focusing supermirror and suggests that the focusing mirror
acts well as a m=3 supermirror. The small value 2.7 Å compared with the designed value 2.79 Å shows somemisalignment or small distortion of the mirror.
In conclusion, The elliptic mirror successfully focused wideband neutron beam (λ > 2.7 Å) into the size of
0.244mm, but some improvements are needed on mirror alignments and distortions at experiments.

Fig.4 Wavelength distributions of the focused andFig.3 Profile of a knife-edge scan on the focused

unfocused beams: inset shows a magnified view

beam with initial slit width 0.10mm

around 2.7 Å.

2