実験報告書様式（装置グループ利用）

MLF Experimental Report

提出日 Date of report

実験装置名／ＢＬ番号 Name of Instrument/BL AMATERAS/BL14
実験装置責任者 Name of the person responsible for the instrument: Kenji Nakajima
所属 Affiliation: J-PARC Center

１．研究成果概要 （a）装置グループ内の成果、（ｂ）ユーザー課題実装時における特筆すべきサポート、（ｃ）
ユーザー課題の執行状況について、まとめてください。A4 サイズ用紙使用のこと。
Outline of your activities.

Following results at your instrument should be reported in A4 size papers: (a)results of your instrument goup, (b) significant user support works, and (c) statistical summary of userexperiments.
AMATERAS (Fig. 1) had five staff members bytaking Dr. Chiba-Kamoshida as outsourcing staff in April
2013, which results in more substantial user support after
eight months of the beam-off period of J-PARC. For
instrumental activities, we have made efforts such as an
upgradeof

thebeam-transport

section,on-beamcommissioning of several new devices as mentioned
below. It should be also reported here that two works
related to AMATERAS were awarded by JapaneseSociety for Neutron Science (JSNS), which aredevelopment of a chopper spectrometer withFigure 1. Photo of AMATERAS (in September, 2013).

apulse-shaping chopper at a pulsed source by Dr.
Nakajima et al. (Fig. 2) and development of model-free
analysis method on quasi-elastic neutron scattering andits application to liquid water by Dr. Kikuchi [1]In JFY2013, following items of instrumental
activities were carried out: 1) commissioning of sample
environment devices, 2) replacement of defectedcomponents and 3) upgrade of components. Also, regular
maintenance of components and regular performance

Figure 2. Photo of the award ceremony in the JSNS meeting

tests were carried out as routine works. 12 days of
instrument-group-use beam-time were spent for on-beam parts of above activities.
In the beginning of 2013A, an operation test of a BL-common 7T cryomanget on AMATERAS was carriedout (Fig. 3). Magnetic fields up to 4T were successfully achieved. Since we were afraid that the scatteringchamber of AMATERAS, which is made of steel, might cause serious damage on the magnet due to magnetic
1１．研究成果概要（つづき） Outline of experimental results (continued).
force, we did not try to apply even higher field. As weexpected, huge background from the outer vacuum
chamber, radiation shields and a support ring for themagnet was observed. Still we could observe a fielddependence of magnetic excitations in a powder sample
by subtracting background data obtained from an empty
scan.
During the long shutdown period of MLF, thebeam-transport

sectionwasup-graded(Fig.

4).

Discrepancy between the intensity expected fromFigure 3. A BL-common 7T cryomanget on AMATERAS.

simulation and that observed in real measurements was
one of serious problems of AMATERAS. Misalignmentof guide tubes and performance of a part of mirrors had
been suspected to be sources of this problem. Therefore,
we replaced the mirrors (8.6 m in length) and re-aligned
full-part of the beam-transport. The performance after
this upgrade was checked in the 2013B period. The
intensity became 1.2 times larger in a low-energy region(Ei < 5 meV) and nearly twice in a high-energy region(Ei > 80 meV) compared to the previous intensity.
However it is still lower than the simulated intensity. We

Figure 4. Re-alignment of AMATERAS beam-transport.

continue investigation including check of validity of thesimulation.
As the other major instrumental activities, replacement of a defected detector tube, installing a Cd filmattenuator, background reduction study were done in JFY 2013.
Research fields of the proposals on AMATERAS had wide variety. In the 2013A and 2013B periods, 14general use proposals were accepted, and six proposals were listed on the reserved subjects. We also accepted
two project use proposals, which are ‘Study of structure and electronic properties of functional materials atBL14’ (PI: T. Masuda) and ‘Project research on structure and dynamics of protonic, superionic and amorphous
functional materials using AMATERAS’ (PI: Y. Inamura), and one element strategy use proposal,‘Neutron-scattering research on element-strategy project for electronic materials’ (PI: Y. Murakami). Due to theaccident at the Hadron Experimental Facility, five general use experiments were cancelled or interrupted. The
beamtime for the project use and element strategy use experiments were also reduced.
[1] T. Kikuchi et. al., Phys. Rev. E 87, 062314 (2013).
必要に応じて、A4 サイズの用紙に続きを記入して下さい。
Please use A4-size papers for further reporting, if necessary.
2