実験報告書様式（プロジェクト利用）

MLF Experimental Report

提出日 Date of report

実験課題番号 Project No.

装置責任者 Name of responsible person

2014P0701

Yosuke Toh

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Research on nuclear astrophysics, nuclear data, andBL04

trace-element analysis using pulsed neutrons

利用期間 Dates of experiments

実験責任者名 Name of principal investigator

2014/4/1～2015/4/10

Atsushi Kimura
所属 Affiliation
Japan Atomic Energy Agency

１．研究成果概要（試料の名称、組成、物理的・化学的性状を明記するとともに、実験方法、利用の結果得られた主なデータ、考察、結論、図表等を記述してください。
Outline of experimental results (experimental method and results should be reported including sample
information such as composition, physical and/or chemical characteristics.
The ANNRI installed at BL04 of J-PARC/MLF was applied for researches of nuclear astrophysics, nuclear
data, and trace-element analysis. In this report, representative results in this project are presented. In
2014 JFY, due to the fire accidents, some experiments were carried over into 2015 JFY.
In the nuclear astrophysics study, a Cd-112 sample was measured and transmission gamma rays to isomerstate of 11/2- are observed. Neutron capture cross section of Nd-142 was measured. The first six
resonances of Nd-142 reported in a previous work were not observed. The experimental results andcross-search of resonance energies in nuclear data libraries suggested that resonances of the impurity
nuclide Pr-141 have been mistakenly assigned as Nd-142 in the previous experiment.
In the activation analytical study, Pd-Ag alloys were measured with the Ge spectrometer. The resonancepeaks of Pd and Ag elements were clearly observed in TOF spectrum. The linearity of the calibration curveexhibits excellent linearity over a wide range of a sample weight by applying the correction for neutron andgamma rays self-shielding effects, etc.
In the nuclear data study, for minor actinide and long lived fission products, measurements of the neutron
capture cross sections of Pd-107, Tc-99 and Am-241 were carried out. For stable isotopes, theneutron-capture cross sections of Sn-120, 122, 124 were measured in the energy range from 10 meV to 2 keVwith an array of germanium detectors in ANNRI. The preliminary result of the neutron-capture cross sectionwas obtained by normalizing the relative cross sections to the data in JENDL 4.0

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１．研究成果概要（つづき） Outline of experimental results (continued).
As examples of neutron-capture cross-section measurements, the measurement Sn-120 is presented. The
measurement was performed with an array of Ge spectrometer in ANNRI. The pulsed neutron beam wascollimated to a 7mm at the sample position. Tin-120 sample was isotopically enriched metallic tin with adiameter of 5 mm. The weight of the sample was 68.7 mg. The isotopic enrichment for the sample was98.8mole%. The sample was chemically contaminated with 60, 400, 500 and 600 ppm of Sb, Al, Fe and Si on thecertification sheet. The total measuring time was about 63 hours for the Sn-120 sample
The obtained neutron-capture cross section for Sn-120 is shown in Fig. 1 together with values of JENDL-4.0
for T = 300 K (broadened with the resolution function) and those of the other impurities. The 67.32- and150-eV resonances were not observed although they were listed on ENDF/B VII.1.

Fig.1 Preliminary results of the neutron-capture cross-sections for 120Sn together with values ofJENDL-4.0 for T = 300 K (broadened with the resolution function) and those of the otherimpurities.
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.
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