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

New high-pressure neutron beamline PLANET in J-PARC

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

no journal, , 

The PLANET is the new high-pressure neutron beamline 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 20 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. We stared designing at 2008 and finished the construction on the last March. The beamline is used by the project members before the next March, and then it will be opened for general users.

High pressure neutron diffractometer "PLANET" at J-PARC

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

no journal, , 

High-pressure neutron diffractometer named "PLANET" is constructed at BL11 of Materials and Life Science Experimental Facility (MLF), spallation neutron source in Japan Proton Accelerator Research Complex (J-PARC). Using the features of neutron scattering that differs from X-ray, the beamline will provide new information not only about hydrogen in minerals, but also order-disorder transition and magnetic structures of minerals. A feature of the beamline is that 6-ram multi anvil press (named "ATSUHIME") is installed to generate high pressure and high temperature. The 6-rams press is suitable for neutron diffraction experiment because it has a wide window for detector coverage compared to other multi anvil press using guide block. Six hydraulic rams are operated by independent plunger pump to achieve highly synchronized compression of the sample assembly. In the talk, I will present the detail design of PLANET and its performance that is demonstrated through the commissioning.

The Performance evaluation of electron tracking Compton camera for medical imaging

Sonoda, Shinya*; Nabetani, Akira*; Kimura, Hiroyuki*; Kabuki, Shigeto*; Takada, Atsushi*; Kubo, Hidetoshi*; Kimura, Shotaro*; Sawano, Tatsuya*; Tanimori, Toru*; Matsuoka, Yoshihiro*; et al.

no journal, , 

We have developed the ETCC for new medical imaging device and succeeded in imaging the some medical imaging reagents. Thus, this detector is thought promising for a new medical imaging. The F-18 point-like and rod-like phantoms are measured with new ETCC, and the imaging performance was estimated. In addition, measurement of Tc-95m which is produced by Japan Atomic Energy Agency was performed.

Application of Electron Tracking Compton Camera (ETCC) in medical imaging

Sonoda, Shinya*; Nabetani, Akira*; Kimura, Hiroyuki*; Kabuki, Shigeto*; Takada, Atsushi*; Kubo, Hidetoshi*; Komura, Shotaro*; Sawano, Tatsuya*; Tanimori, Toru*; Matsuoka, Yoshihiro*; et al.

no journal, , 

We present the performance results using this new ETCC such as the imaging test using F-18 in point-like and rod-like phantoms with varying the intense of radiation. In addition, the measurementof Tc-95m which is produced by Japan Atomic Energy Agency was performed. Tc-95m emitsthe -rays with the energy, 204, 583, and 835 keV, and then an image with multi-energies is examined. The position resolution achieves less than about 8 degrees from 10 degrees at 511 keV by this improvement. Further improvement of the angular resolution (position resolution) will be presented until 2015 spring. Also, we are developing the next ETCC by increasing the thickness of the scintillator from 1 rad. to 2 rad. and the gas pressure from 1 atm to 3 atm which improvethe detection efficiency by a factor of 5 at 511 keV. By these improvements, the imaging time of mouse is expected to be reduced from several hours with to 20 minutes for lots of kinds of RIs with the energy band from 0.1-2 MeV.