Development of a neutron scintillator for a compact NRTA system, 2

Lee, J.; Hironaka, Kota; Ito, Fumiaki*; Takahashi, Tone; Koizumi, Mitsuo; Hori, Junichi*; Terada, Kazushi*

KURNS Progress Report 2021, P. 97, 2022/07

https://www.rri.kyoto-u.ac.jp/PUB/report/PR/ProgRep2021/ProgressReport2021_online.pdf

no abstracts in English

Neutron capture and total cross-section measurements and resonance parameter analysis of niobium-93 below 400 eV

Endo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Rovira Leveroni, G.; Terada, Kazushi*; Meigo, Shinichiro; Toh, Yosuke; Segawa, Mariko; et al.

Journal of Nuclear Science and Technology, 59(3), p.318 - 333, 2022/03

https://doi.org/10.1080/00223131.2021.1970040

Development of a neutron sintillator for a compact NRTA system

Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Hori, Junichi*; Terada, Kazushi*; Koizumi, Mitsuo

KURNS Progress Report 2020, P. 98, 2021/08

A compact Nuclear Resonance Transmission Analysis (NRTA) system using a Laser Driven Neutron Source (LDNS) has been developed as a part of the development of nuclear non-proliferation technology supported by the MEXT. In NRTA, the neutron energy emitted from a pulsed neutron source is measured using the time-of-flight (TOF) method. LDNS is of interest because of its short pulse width, which is necessary for accurate TOF measurements over short flight distances. In the short-distance TOF measurement, there will be a large gamma-ray background event due to the coincidence of the timing of the arrival of 2.2 MeV gamma-rays due to neutron capture on hydrogen in the moderator and the timing of the arrival of neutrons around the resonance energy. Since the LDNS is still under development, the neutron flux is not sufficient and it is desirable to use a detector with high detection efficiency. For these reasons, we have developed a detector with low efficiency to gamma-rays and high efficiency to neutrons (multilayer neutron detector). As one of the results of this year's experiments, we confirmed that the multilayer neutron detector have low sensitivity to gamma-rays.

Discovery of a new low energy neutron resonance of Y

Katabuchi, Tatsuya*; Toh, Yosuke; Mizumoto, Motoharu*; Saito, Tatsuhiro*; Terada, Kazushi*; Kimura, Atsushi; Nakamura, Shoji; Huang, M.*; Rovira Leveroni, G.; Igashira, Masayuki*

European Physical Journal A, 57(1), p.4_1 - 4_4, 2021/01

https://doi.org/10.1140/epja/s10050-020-00320-8

Fast neutron capture reaction data measurement of minor actinides for development of nuclear transmutation systems

Katabuchi, Tatsuya*; Iwamoto, Osamu; Hori, Junichi*; Kimura, Atsushi; Iwamoto, Nobuyuki; Nakamura, Shoji; Shibahara, Yuji*; Terada, Kazushi*; Rovira, G.*; Matsuura, Shota*

EPJ Web of Conferences, 239, p.01044_1 - 01044_4, 2020/09

https://doi.org/10.1051/epjconf/202023901044

Neutron capture reaction data measurement of minor actinides in fast neutron energy region for study on nuclear transmutation system

Katabuchi, Tatsuya*; Iwamoto, Osamu; Hori, Junichi*; Iwamoto, Nobuyuki; Kimura, Atsushi; Nakamura, Shoji; Shibahara, Yuji*; Terada, Kazushi*

JAEA-Conf 2019-001, p.193 - 197, 2019/11

https://doi.org/10.11484/jaea-conf-2019-001

Measurements of gamma-ray emission probabilities in the decay of americium-244g

Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*

Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01

https://doi.org/10.1080/00223131.2018.1539353

Accurate data of -ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by -ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces Am after neutron capture. The 744-keV -ray decaying from the ground state of Am has a relatively large -ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the -ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the -ray emission probability was measured by using an activation method and an examined level structure of Cm. In this study, the emission probability of 744-keV ray was derived as 66.51.1%, and its uncertainty was improved from 29% to 2%.

Resonance analysis of cross section data measured by J-PARC/MLF using the modified REFIT code

Mizuyama, Kazuhito; Iwamoto, Nobuyuki; Iwamoto, Osamu; Terada, Kazushi; Nakao, Taro

JAEA-Conf 2017-001, p.163 - 168, 2018/01

https://doi.org/10.11484/jaea-conf-2017-001

Developments of a new data acquisition system at ANNRI

Nakao, Taro; Terada, Kazushi; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; Hori, Junichi*

EPJ Web of Conferences, 146, p.03021_1 - 03021_4, 2017/09

https://doi.org/10.1051/epjconf/201714603021

A new data acquisition system (DAQ system) in J-PARC Materials and Life Science Experimental Facility (MLF) ANNRI was developed. Increasing beam power of MLF in recent years allows beam line users to obtain high quantity experimental data yields. Compared to 2008, more than 20 times beam current is achieved in 2015. For the purpose to correspond strong beam power of MLF, a new DAQ system for the array of the Ge detectors in ANNRI is developed. The DAQ system is also going to be used for processing signals from a Li glass detector, which is under development at ANNRI for measurement of total neutron cross sections. Commissioning experiment of a new DAQ system at ANNRI was performed by using 0.1mmt Au sample with 500kW J-PARC proton beam power. An applicability of time-of-flight method for both neutron capture and total cross-sections measurements was checked. ADC and TDC nonlinearity, energy resolution, multi-channel coincidence and dead time performance for the array of the Ge detectors were also evaluated. The dead time value for Ge detectors was successfully decreased to 1/4 from the previous DAQ system with minor deterioration on energy resolution. The author would like to thank the accelerator and technical staff at J-PARC for operation of the accelerator and the neutron production target and for the other experimental supports. Present study includes the result of "Research and Development for accuracy improvement of neutron nuclear data on minor actinides" entrusted to the Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).

Measurements of -ray emission probabilities of Am and Np

Terada, Kazushi; Nakamura, Shoji; Nakao, Taro; Kimura, Atsushi; Iwamoto, Osamu; Harada, Hideo; Takamiya, Koichi*; Hori, Junichi*

Journal of Nuclear Science and Technology, 53(11), p.1881 - 1888, 2016/11

https://doi.org/10.1080/00223131.2016.1174167

-ray emission probabilities of Am and Np have been precisely measured with - and -ray spectroscopic methods. The activities of Am samples were determined by measuring alpha particles using a Si semiconductor detector. -rays emitted from the samples were measured with a planar type High-Purity Germanium (HPGe) detector. An efficiency curve of the Ge detector was derived with uncertainties of 0.7% from 50 to 1332 keV and 1.3% below 50 keV by combining measured efficiencies and Monte Carlo simulation. The -ray emission probabilities for the major -rays of these nuclides were determined with uncertainties less than 1.2%.