Demonstration of a neutron resonance transmission analysis system using a laser-driven neutron source

Hironaka, Kota; Ito, Fumiaki*; Lee, J.; Koizumi, Mitsuo; Takahashi, Tone; Suzuki, Satoshi*; Yogo, Akifumi*; Arikawa, Yasunobu*; Abe, Yuki*

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11

Neutron resonance transmission analysis (NRTA) is a method for non-destructive measurement of nuclear material by using a time-of-flight (TOF) technique with a pulsed neutron source. For NRTA system to carry out the short-distance TOF measurements with high resolutions, a short-pulsed neutron source is required. Laser-driven neutron sources (LDNSs) is very suitable as such a neutron source because of its short pulse width. Moreover, the compactness of the laser system is also expected due to the remarkable development of laser technology in recent years. In the present study, we have developed a technology for applying LDNS to the NRTA system and conducted the demonstration experiment using the LFEX laser at Osaka University to investigate the feasibility of the system. In this experiment, we successfully observed the neutron resonance peaks of indium and silver samples.

Evaluation of a one-dimensional position-sensitive quartz optical fiber sensor based on the time-of-flight method for high radiation dose rate applications

Terasaka, Yuta; Watanabe, Kenichi*; Uritani, Akira*

Nuclear Instruments and Methods in Physics Research A, 996, p.165151_1 - 165151_8, 2021/04

https://doi.org/10.1016/j.nima.2021.165151

For the measurement of radiation distribution inside the Fukushima Daiichi Nuclear Power Station (FDNPS) buildings, the evaluation of a small-diameter quartz optical fiber as a one-dimensional position-sensitive sensor was conducted. The sensor determines the incident position of radiation into the fiber using the time-of-flight information of emitted Cerenkov photons in the optical fiber. Compared with the conventional sensor using the plastic scintillating fiber, the quartz optical fiber has much higher position resolution, which may be the result of the improvement of timing characteristics caused by the prompt emission mechanism of the Cerenkov radiation. Additionally, the response of position-sensitive quartz optical fiber sensor under high radiation field was evaluated, and good count rate linearity was confirmed using the 10 m long quartz optical fiber with a diameter of 0.4 mm up to the dose rate at least 20 mSv/h, and the radiation tolerance property up to the accumulated dose of 1 kGy was evaluated.

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).

Study on response function of organic liquid scintillator for high-energy neutrons

Satoh, Daiki; Sato, Tatsuhiko; Endo, Akira; Yamaguchi, Yasuhiro; Takada, Masashi*; Ishibashi, Kenji*

AIP Conference Proceedings 769, p.1680 - 1683, 2005/05

https://doi.org/10.1063/1.1945332

Response function of liquid organic scintillators is essential to derive the accurate neutron spectrum. Experimental data above 100 MeV, however, are very scarce. The existing Monte Carlo codes, SCINFUL and CECIL, are often used for estimation of the response function instead of the experimental data. These codes are known to reproduce well the response function for incidences below 100 MeV. Unfortunately, the codes are not applicable to the calculation in the higher energy region. In order to determine the response functions above 100 MeV, a new Monte Carlo code, designated as SCINFUL-QMD, has been developed. In the comparison with the experimental data up to 800 MeV, the validation of SCINFUL-QMD was confirmed. The results of SCINFUL-QMD agreed with the experimental data better than those of other calculation codes.

Measurement of neutron capture cross sections of Tc-99

JNC TJ9400 2000-008, 61 Pages, 2000/02

JNC-TJ9400-2000-008.pdf:2.5MB

For studies on nuclear transmutation of long-lived fission products (LLFPs) in a fast reactor, detailed characteristics of reactor core such as transmutation performance have to be investigated, so accurate neutron cross section data of LLFPs become necessary. Therefore, the keV-neutron capture cross sections of Tc-99, which is one of important LLFPs, were measured in the present study to obtain the accurate data. The measurement was relative to the standard capture cross sections of Au-197. A neutron time-of-flight method was adopted with a ns-pulsed neutron source by a Pelletron accelerator and a large anti-Compton NaI(TI) gamma-ray detector. As a result, the capture cross sections of Tc-99 were obtained with the error of about 5 % in the incident neutlon energy region of 10 to 600 keV. The present data were compared with other experimental data and the evaluated values of JENDL-3.2, and it was found that the evaluations of JENDL-3.2 were 15-20 % smaller than the present measurements.

Benchmark experiment on vanadium assembly with D-T Neutrons; Leakage neutron spectrum measurement

Kokooo*; Murata, Isao*; Nakano, D.*; Takahashi, Akito*; Maekawa, Fujio; Ikeda, Yujiro

Fusion Technology, 34(3), p.980 - 984, 1998/11

no abstracts in English

Measurement of fast neutron induced fission cross section of minor-actinide

PNC TJ9601 97-001, 51 Pages, 1997/03

PNC-TJ9601-97-001.pdf:1.05MB

In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA:Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy.In this study fast neutron induced fission cross section of MA is measured using Dynamitron Accelerator in Tohoku University. The experimental method and the samples, which were developed or introduced during the last year, were improved in this fiscal year: (1)Development of a sealed fission chamber, (2)Intensification of Li neutron target, (3)Improvement of time-resolution of Time-of-flight (TOF) electronic circuit, (4)Introduction of Np237 samples with large sample mass and (5)Introduction of a U235 sample with high purity. Using these improved tools and samples, the fission cross section ratio of NP237 relative to U235 was measured between 5 to 100keV, and the fission cross section of Np237 was deduced. On the other hand, samples of Am241 and Am243 were obtained from Japan Atomic Energy Research Institute (JAERI) after investigating fission cross section of two americium isotopes (Am241 and Am243) which are important for core physics calculation of fast reactors.

Spallation neutron measurement by the time-of-flight method with a short flight path

; ; ; Shigyo, Nobuhiro*; Maehata, Keisuke*; Meigo, Shinichiro; Takada, Hiroshi; Chiba, Satoshi; Numajiri, M.*; Nakamura, Takashi*; et al.

Journal of Nuclear Science and Technology, 32(9), p.827 - 833, 1995/09

https://doi.org/10.3327/jnst.32.827

no abstracts in English

Design study of a time-of-flight neutron spectrometer for JT-60U

T.Elevant*; M.Hoek*; Nishitani, Takeo

JAERI-M 93-123, 20 Pages, 1993/06

JAERI-M-93-123.pdf:0.92MB

no abstracts in English

Neutron transmission measurements on Sb, Sb, Ce and Ce in the resonance region

Okubo, Makio; Mizumoto, Motoharu; Nakajima, Yutaka

JAERI-M 93-012, 44 Pages, 1993/02

JAERI-M-93-012.pdf:1.37MB

no abstracts in English