Quantitative visualization of a radioactive plume in a nuclear accident

Nagai, Haruyasu; Nakayama, Hiromasa; Satoh, Daiki; Tanimori, Toru*

Dai-52-Kai Kashika Joho Shimpojiumu Koen Rombunshu (Internet), 4 Pages, 2024/07

A novel monitoring method for the quantitative visualization of 3D distribution of a radioactive plume accidentally released from a nuclear facility is proposed, and the feasibility of its analysis method is demonstrated by preliminary test using hypothetical data. The proposed method is the combination of gamma-ray imaging spectroscopy with the electron tracking Compton camera (ETCC) and real-time high-resolution atmospheric dispersion simulation based on 3D wind observation with Doppler lidar. ETCC can acquire the angle distribution images of direct gamma-ray from a specific radionuclide in a target radioactive plume. The 3D distribution of radioactive plume is inversely reconstructed from direct gamma-ray images by several ETCCs located around the target by harmonizing with the air concentration distribution pattern of the plume predicted by real-time atmospheric dispersion simulation. Analysis methods were developed and tested by using hypothetical data generated by numerical simulations of atmospheric dispersion and radiation transport.

Experimental visualization of water/ice phase distribution at cold start for practical-sized polymer electrolyte fuel cells

Higuchi, Yuki*; Yoshimune, Wataru*; Kato, Satoru*; Hibi, Shogo*; Setoyama, Daigo*; Isegawa, Kazuhisa*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Harada, Masashi*; et al.

Communications Engineering (Internet), 3, p.33_1 - 33_7, 2024/02

https://doi.org/10.1038/s44172-024-00176-6

Design and performance of high-pressure PLANET beamline at pulsed neutron source at J-PARC

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Komatsu, Kazuki*; Yamada, Akihiro*; Inamura, Yasuhiro; Nakatani, Takeshi; Seto, Yusuke*; Nagai, Takaya*; Utsumi, Wataru; et al.

Nuclear Instruments and Methods in Physics Research A, 780, p.55 - 67, 2015/04

https://doi.org/10.1016/j.nima.2015.01.059

PLANET is a time-of-flight (ToF) neutron beamline dedicated to high-pressure and high-temperature experiments. The large six-axis multi-anvil high-pressure press designed for ToF neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators to eliminate parasitic scattering from the high-pressure cell assembly. The high performance of the diffractometer for the resolution ( / 0.6%) and the accessible -spacing range (0.2-8.4 ) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Progress in R&D efforts on the energy recovery linac in Japan

Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06

Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.

360-W average power operation with a single-stage diode-pumped Nd:YAG amplifier at a 1-kHz repetition rate

Kiriyama, Hiromitsu; Yamakawa, Koichi; Nagai, Toru; Kageyama, Nobuto*; Miyajima, Hirofumi*; Kan, Hirofumi*; Yoshida, Hidetsugu*; Nakatsuka, Masahiro*

Optics Letters, 28(18), p.1671 - 1673, 2003/09

https://doi.org/10.1364/OL.28.001671

no abstracts in English

The Performance of the J-PARC high-pressure neutron diffractometer PLANET revealed by the commissioning

Hattori, Takanori; Sano, Asami; Shioya, Masahiro; Yamada, Akihiro*; Arima, Hiroshi*; Inoue, Toru*; Inamura, Yasuhiro; Ito, Takayoshi*; Komatsu, Kazuki*; Kagi, Hiroyuki*; et al.

no journal, , 

The PLANET is the world's first neutron beamline specialized for high-pressure and high-temperature experiments. The most characteristic feature is the capability to investigate the state of the matter at high-pressure and high-temperatures up to 20 GPa and 2000 K with the multi-anvil high-pressure apparatus. The construction was started in 2008, and the beamline was commissioned in the last spring. The performance revealed by the commissioning will be introduced. The resolution of the diffraction pattern (d/d = 0.6%) was found to be almost equal to the designed value (0.5%). The elimination of the background from the sample surrounding materials, which is the most important feature of the high-pressure experiments, was found to be accomplished with the use of the severe incident collimator and radial receiving collimator system. The beamline is used by project members since this autumn and will be opened for general users in the next April.

SUGOROKU of the BL11 construction

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Utsumi, Wataru; Nagai, Takaya*; Iitaka, Toshiaki*; Kagi, Hiroyuki*; Katayama, Yoshinori; Inoue, Toru*; Yagi, Takehiko*

no journal, , 

The PLANET is the new high-pressure neutron beamline now being constructed at the intense pulsed neutron source J-PARC. This beamline aims at revealing the effect of water on dynamics of the interior of the Earth and planets by using the neutron character that is sensitive to hydrogen. The most characteristic feature of this beamline is to possess the huge 6-axis press with the maximum load of 500 ton/axis, which can simultaneously generate high-pressure and high-temperature condition of 30 GPa and 2000 K. Coupled with the state-of-the-art techniques in neutron diffraction and radiography, the beamline offers the microscopic and macroscopic information of materials at high-PT condition. The construction was started in 2008/11 and the 80% of the construction has finished now. During the construction, we took many disasters. This paper introduces the process based on the SUGOROKU form.

Overview and current construction state of J-PARC high-pressure neutron diffractometer PLANET

Hattori, Takanori; Arima, Hiroshi; Abe, Jun; Sano, Asami; Utsumi, Wataru; Nagai, Takaya*; Kagi, Hiroyuki*; Iitaka, Toshiaki*; Katayama, Yoshinori; Inoue, Toru*; et al.

no journal, , 

The new beamline dedicated to high-pressure studies, PLANET is now being constructed at BL11 in MLF/J-PARC. The design concept and the current construction state are introduced. The most characteristic feature of this beamline is a huge press with the maximum load of 1500 ton. The coupling this with the state of the art neutron techniques reveals hydrogen positions and its effects on the physical properties of materials and minerals at tens of gigapascals and a few thousand Kelvins. This opens the door to explore deep interior of the hydrous Earth and Planets.

High-pressure neutron beamline PLANET at J-PARC; Its performance and safety control

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Inamura, Yasuhiro; Nagai, Takaya*; Katayama, Yoshinori; Inoue, Toru*; Kagi, Hiroyuki*; Yagi, Takehiko*

no journal, , 

The PLANET is the high-pressure beamline newly constructed at J-PARC in JAPAN. The most characteristic feature is to possess the huge 6-axis press (ATSUHIME) with the maximum load of 500 ton/axis, which can generate high-PT condition of 10 GPa and 2000 K and the higher potentially. By using neutron diffraction and radiography techniques, the beamline offers microscopic and macroscopic information of materials at high-PT conditions. The beamline is designed so as to analyze structures of both crystalline and amorphous materials. In designing, we focused on obtaining clear pattern even from tiny high-pressure sample. To eliminate the scattering from sample surrounding materials, such as miniature furnace and sample containers in the high-pressure cell, PLANET is equipped with severe incident and receiving collimators. This system confines the diffraction gauge volume into less than 3mm cube and was found to completely eliminate Bragg peaks from the sample surrounding materials even at 10 GPa. The beamline is now being used by project members and many scientific results are about to be born. This beamline became a public beamline and will be opened for general users in the next February.