Experimental characterization of high-energy component in extracted pulsed neutrons at the J-PARC spallation neutron source

Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Takada, Hiroshi; Ikeda, Yujiro

Nuclear Instruments and Methods in Physics Research A, 1000, p.165252_1 - 165252_8, 2021/06

https://doi.org/10.1016/j.nima.2021.165252

This study explores high-energy neutron components of the extracted neutron beam at J-PARC pulsed neutron source using the foil activation method with threshold reactions. Foils of aluminum, gold, bismuth, niobium, and thulium were used to cover the neutron energy range from 0.3 MeV to 79.4 MeV. The experiment was performed using neutron beams of BL10 (NOBORU). The foils were irradiated by a neutron beam at 13.4 m from the moderator. To characterize high-energy neutron fields for irradiation applications, reaction rates in three different configurations with and without BC slit and Pb filter were examined. To compare the experiments with calculations given for the user, reaction rates for corresponding reactions were calculated by the PHITS code with the JENDL-3.2 and the JENDL dosimetry file. Although there was a systematic tendency in C/E (Calculation/Experiment) ratios for different threshold energies, which C/E ratio decreased as threshold energy increased up to 100 MeV, and all C/E ratios were in the range of 1.00.2. This indicated that high-energy neutron calculations were adequate for the analysis of experimental data for NOBORU users.

Calibration of epithermal neutron beam intensity for dosimetry at JRR-4

Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Sakurai, Yoshinori*; Kobayashi, Toru*

Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 15 Pages, 2004/10

To carry out the boron neutron capture therapy (BNCT) using the epithermal neutron, the epithermal neutron beam intensity was measured by using Au reaction rate activated on the resonance absorption peak (4.9eV). Two scaling factors, which are the reactor power calibration factor and the calculation/experiment (C/E) scaling factor, are necessary in order to correct with the simulation and actual irradiation experiment. First, an optimum detector position was investigated using MCNP code. The result of MCNP calculation showed that the influence of subject placed at the collimator was below 1% when the detector was placed in the distance of over 20cm from the collimator. Therefore we installed the monitor holders near the bismuth block in order to set three gold wire monitors. The factors were determined in the calibration experiments that measure the thermal neutron flux in the phantom and reaction rate of the gold wire monitors. The monitoring technique to measure epithermal neutron beam intensity was applied to clinical irradiation with the epithermal neutron beam.

In-phantom two-dimensinal thermal neutron distribution for intraoperative boron neutron capture therapy of brain tumours

Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Shibata, Yasushi*; Nose, Tadao*

Physics in Medicine & Biology, 47(14), p.2387 - 2396, 2002/07

https://doi.org/10.1088/0031-9155/47/14/302

The aim of this study was to determine the in-phantom thermal distribution derived from neutron beams for intraoperative boron neutron capture therapy (IOBNCT). Gold activation wires arranged in a cylindrical water phantom with (void-in phantom) or without (standard phantom) a cylinder styrene form placed inside were irradiated by using the epithermal beam (ENB) and the mixed thermal-epithermal beam (TNB-1) at the JRR-4. The thermal neutron distribution derived from both the ENB and TNB-1 was significantly improved in the void-in-phantom, and a double high dose area was formed lateral to the void. The flattened distribution in the circumference of the void was observed with the combination of ENB and the void-in-phantom. The measurement data suggest that the ENB may provide a clinical advantage in the form of an enhanced and flattened dose delivery to the marginal tissue in which residual and/or microscopically infiltrating tumor.

Measurement of induced radioactivity in copper exposed to high energy heavy ion beam

Kim, E.; Nakamura, Takashi*; Uwamino, Y.*; Ito, S.*; Fukumura, A.*

Journal of Nuclear Science and Technology, 37(Suppl.1), p.811 - 815, 2000/03

https://doi.org/10.1080/00223131.2000.10875003

no abstracts in English

Neutron activation for ITER

Barnes, C. W.*; Loughlin, M. J.*; Nishitani, Takeo

Review of Scientific Instruments, 68(1), p.577 - 580, 1997/01

https://doi.org/10.1063/1.1147657

no abstracts in English

Concept and characteristics of a simulated line source for annular blanket experiments using an accelerator-based deuterium-tritium neutron source

Oyama, Yukio; Konno, Chikara; Ikeda, Yujiro; Kosako, Kazuaki*; Maekawa, Hiroshi; Nakamura, Tomoo; M.A.Abdou*; Bennett, E. F.*; A.Kumar*; *; et al.

Fusion Technology, 28(2), p.305 - 319, 1995/09

no abstracts in English

Neutron yield measurements by use of foil activation at JT-60U

M.Hoek*; Nishitani, Takeo; Ikeda, Yujiro; Morioka, Atsuhiko

Review of Scientific Instruments, 66(1), p.885 - 887, 1995/01

https://doi.org/10.1063/1.1146527

no abstracts in English

A Review of shielding experiments for fusion reactor at FNS/JAERI

Maekawa, Hiroshi; Oyama, Yukio; Tanaka, Shunichi

Proc. of the Topical Meeting on New Horizons in Radiation Protection and Shielding, p.611 - 618, 1992/00

no abstracts in English

Fusion Blanket Benchmark Experiments on a 60cm-Thick Lithium-Oxide Cylindrical Assembly

; ; ; ; ; ; ; ;

JAERI-M 86-182, 78 Pages, 1986/12

JAERI-M-86-182.pdf:2.31MB

no abstracts in English

Monte Carlo Calculation of Characteristics of Source Neutrons and Irradiation Field of the FNS Rotating Target

; ; ; ; ; *; *

JAERI-M 84-193, 34 Pages, 1984/10

JAERI-M-84-193.pdf:0.65MB

no abstracts in English