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Journal Articles

The Precise energy spectra measurement of laser-accelerated MeV/n-class high-Z ions and protons using CR-39 detectors

Kanasaki, Masato; Jinno, Satoshi*; Sakaki, Hironao; Kondo, Kiminori; Oda, Keiji*; Yamauchi, Tomoya*; Fukuda, Yuji

Plasma Physics and Controlled Fusion, 58(3), p.034013_1 - 034013_6, 2016/03

 Times Cited Count:16 Percentile:77.96(Physics, Fluids & Plasmas)

In order to understand the synergetic interplay between the Coulomb explosion of clusters and the background gas dynamics, we have conducted ion acceleration experiments using CO$$_2$$ clusters (250 nm in dia.) embedded in background H$$_2$$ gas with the J-KAREN laser (1 J, 40 fs, 10$$^{-10}$$ contrast) at JAEA-KPSI. By a careful analysis of etch pit positions on CR-39 and their structures including the etch pit growth behavior analysis with the multi-step etching technique, energy spectra for protons from the background gas and carbon/oxygen ions from the clusters are obtained separately. The maximum energies of protons and carbon/oxygen ions are determined as 1.6 MeV and 1.1 MeV/u, respectively. Based on the experimental results, the acceleration mechanism of the background gas ions induced by Coulomb explosion of clusters is discussed with the help from numerical simulations which employ a particle-in-cell (PIC) method including relaxation and ionization processes of plasma particles.

Journal Articles

Discrimination method of etch pits created by laser-accelerated protons and recoiled protons by photo-neutrons using CR-39

Kanasaki, Masato; Fukuda, Yuji; Kondo, Kiminori; Oda, Keiji*; Yamauchi, Tomoya*

Reza Kenkyu, 42(2), p.168 - 173, 2014/02

In laser-driven ion acceleration experiments using the cluster-gas targets, a significant amount of fast electrons, which drives the ion acceleration, are produced along with high energy ions with several-tens of MeV. In our recent experiment using CO$$_2$$ clusters embedded in H$$_2$$ gas conducted with the J-KAREN laser facility (1 J, 40 fs) at JAEA-KPSI, the maximum energy of electrons reaches up to 200 MeV. Such fast electrons can produce photo-neutrons via bremsstrahlung processes followed by photo-nuclear reactions. When the CR-39 is exposed to photo-neutrons, it records etchable tracks of generated ions depending on their species and energy as background noises. In order to diagnose the laser-accelerated protons precisely using CR-39, we have developed the discrimination method for laser-accelerated protons and photo-neutrons on CR-39 based on the incident angle and incident energy.

Journal Articles

Generation of 50-MeV/u He ions in laser-driven ion acceleration with cluster-gas targets

Fukuda, Yuji; Sakaki, Hironao; Kanasaki, Masato; Yogo, Akifumi; Jinno, Satoshi; Tampo, Motonobu*; Faenov, A. Ya.*; Pikuz, T. A.*; Hayashi, Yukio; Kando, Masaki; et al.

Proceedings of SPIE, Vol.8779 (Internet), p.87790F_1 - 87790F_7, 2013/05

 Times Cited Count:0 Percentile:0.05

We demonstrate a new ion diagnosis method for high energy ions by utilizing a combination of a single CR-39 detector and plastic plates, which enables to detect high energy ions beyond the detection threshold limit of the CR-39. This detection method coupled with a magnetic spectrometer is applied to identify high energy ions of 50 MeV per nucleon in laser-driven ion acceleration experiments using cluster-gas targets.

Journal Articles

Identification of high energy ions using backscattered particles in laser-driven ion acceleration with cluster-gas targets

Fukuda, Yuji; Sakaki, Hironao; Kanasaki, Masato; Yogo, Akifumi; Jinno, Satoshi; Tampo, Motonobu; Faenov, A. Ya.*; Pikuz, T.; Hayashi, Yukio; Kando, Masaki; et al.

Radiation Measurements, 50, p.92 - 96, 2013/03

 Times Cited Count:12 Percentile:73.42(Nuclear Science & Technology)

A new diagnosis method for high energy ions utilizing a single CR-39 detector mounted on plastic plates is demonstrated to identify the presence of the high energy component beyond the CR-39's detection threshold limit. On irradiation with a 25 MeV per nucleon He ion beam from conventional rf-accelerators, a large number of etch pits having elliptical opening shapes are observed on the rear surface. Detailed investigations reveal that these etch pits are created by heavy ions inelastically backscattered from the plastic plates. This ion detection method is applied to laser-driven ion acceleration experiments using cluster-gas targets, and acceleration of ions with energies up to 50 MeV per nucleon are identified.

Journal Articles

A High energy component of the intense laser-accelerated proton beams detected by stacked CR-39

Kanasaki, Masato; Hattori, Atsuto; Sakaki, Hironao; Fukuda, Yuji; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Ogura, Koichi; Kondo, Kiminori; Oda, Keiji*; et al.

Radiation Measurements, 50, p.46 - 49, 2013/03

 Times Cited Count:11 Percentile:70.63(Nuclear Science & Technology)

A precise measurement has been made utilizing a stacked CR-39 detectors unit for laser accelerated high intensity protons. The proton beams are derived from a thin polyimide target exposed to an high intense Ti:sapphire laser 8 J energy and 40 fs duration. The sample sets, stacked radiochromic film and CR-39 detectors covered with 13 $$mu$$m aluminum filter, are irradiated under vacuum condition. By analyzing the etch pits on the last layer of CR-39 which recorded etchable tracks, the proton energy in high energy region is evaluate more precisely than in the past. The residual ranges for each particle in the last layer has been obtained from etch pit growth curves with multi-stepetching technique. The maximum energy of proton is 14.39$$pm$$0.05 MeV. This method allows us to measure the maximum energy of proton precisely, which is obtained up to the hundredth place in unit of MeV in the laser-driven particle acceleration experiment.

Journal Articles

A Diagnosis of intense ion beam by CR-39 detectors analyzing the back scattered particles

Kanasaki, Masato; Yamauchi, Tomoya*; Fukuda, Yuji; Sakaki, Hironao; Hori, Toshihiko*; Tampo, Motonobu; Kurashima, Satoshi; Kamiya, Tomihiro; Oda, Keiji*; Kondo, Kiminori

AIP Conference Proceedings 1465, p.142 - 147, 2012/07

 Times Cited Count:1 Percentile:49.39

A new diagnosis method has been developed utilizing back scattered particles for high energy intense ion beams. The CR-39 detector mounted on the uniform back-scatterer was irradiated with $$^{4}$$He$$^{2+}$$ ions with an energy 25 MeV/n, which is never recorded as etchable track in CR-39. We found that it is possible to diagnose the high energy intense ion beams by analyzing the etch pits created on the rear surface of CR-39 that directly contacted on the back-scatterers. It turns out that most of etch pits in the rear surface are made by the backscattered particles through the investigation of the growth pattern of each etch pit with multi-step etching technique. This method allows simple diagnosis of the ion beam profile and the presence of high energy component of ions beyond the detection threshold limit of the CR-39 in mixed radiation fields such as laser-driven ion acceleration experiments.

Journal Articles

The Diagnosis method for high-energy ion beams using backscattered particles for laser-driven ion acceleration experiments

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Hori, Toshihiko; Tampo, Motonobu; Kondo, Kiminori; Kurashima, Satoshi; Kamiya, Tomihiro; Oda, Keiji*; Yamauchi, Tomoya*

Japanese Journal of Applied Physics, 51(5), p.056401_1 - 056401_4, 2012/05

 Times Cited Count:6 Percentile:29.66(Physics, Applied)

A single CR-39 detector mounted on plastic plates is irradiated with a 100 MeV He ion beam. Although the beam energy is much greater than the detection threshold limit of the CR-39 detector, a large number of etch pits having elliptical openings are observed on the rear surface. Detailed investigations reveal that these etch pits are created by heavy ions inelastically backscattered from the plastic plates. This method allows a simple diagnosis of the ion beam profile and the presence of the high-energy component beyond the detection threshold limit of the CR-39 detector, especially in mixed-radiation fields such as laser-driven ion acceleration experiments.

Journal Articles

Application of CR-39 solid state nuclear track detector to ion beam diagnosis

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Nishiuchi, Mamiko; Kondo, Kiminori; Kurashima, Satoshi; Kamiya, Tomihiro; Hattori, Atsuto*; Oda, Keiji*; Yamauchi, Tomoya*

Purazuma, Kaku Yugo Gakkai-Shi, 88(5), p.261 - 275, 2012/05

CR-39 solid state nuclear track detector, which was developed for optical lens, has been applied for various field such as radon surveys, measurement of galactic cosmic ray, cell irradiation experiment and so on. The CR-39 detectors have the great advantages of being insensitive to high energy photons and electrons and capable of detecting only ions in the mixed fields such as laser driven relativistic plasmas. Though there are some analytical methods of CR-39 to diagnose ion beam, unfortunately, only few researchers in the field of plasma know the methods. This article looks at how to use CR-39 detectors and introduce the accomplishment of the joint study JAEA and Kobe Univ. for application of CR-39 detectors to ion beam diagnosis.

Journal Articles

Discussion on concepts for radiological dosimetric quantities in the Japan Health Physics Society

Takahashi, Fumiaki; Oda, Keiji*

JAEA-Conf 2007-002, p.171 - 176, 2007/02

no abstracts in English

Journal Articles

Some comments on current system of dosimetric quantities

Oda, Keiji*; Takahashi, Fumiaki; Expert Committee on Concepts of Dosimetric Quantities Used in Radiological protection, Japan Health

Proceedings of 2nd Asian and Oceanic Congress Radiological Protection (AOCRP-2) (CD-ROM), p.52 - 55, 2006/10

no abstracts in English

Journal Articles

Development of rapid dose assessment program from activated sodium in human body for criticality accident

Takahashi, Fumiaki; Endo, Akira; Yamaguchi, Yasuhiro; Oda, Keiji*

Hoken Butsuri, 41(3), p.180 - 187, 2006/09

no abstracts in English

Journal Articles

Radiator design for detecting high-energy neutrons with a nuclear track detector

Oda, Keiji*; Imasaka, Yuichi*; Yamauchi, Tomoya*; Nakane, Yoshihiro; Endo, Akira; Tawara, Hiroko*; Yamaguchi, Yasuhiro

Radiation Measurements, 40(2-6), p.570 - 574, 2005/11

 Times Cited Count:7 Percentile:47.08(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Probe measurements; Fundamentals to advanced applications

Amemiya, Hiroshi*; Wada, Motoi*; Toyoda, Hirotaka*; Nakamura, Keiji*; Ando, Akira*; Uehara, Kazuya; Oyama, Koichiro*; Sakai, Osamu*; Tachibana, Kunihide*

Purazuma, Kaku Yugo Gakkai-Shi, 81(7), p.482 - 525, 2005/07

This article is asked to write by the Japan Society of Plasma Science and Nuclear Fusion Research. The probe diagnostics in fusion plasma is explaind for many readers of the Journal of Plasma and Fusion Research, who have much concerned on various aspects.In section one, the method to estimate the electron temperature and the density as well as the electron energy distribution function with the single probe is given. In section two, the method to estimate the ion temperature and the flow velocity with the double probe is given. The practical measurements are explained introducing the data obtained at JFT-2, JFT-2a and JFT-2M in JAERI tokamak.

JAEA Reports

Scattering Profiles of Sparks and Combustibility of Filter against Hot Sparks

Asazuma, Shinichiro; Okada, Takashi; Kashiro, Kashio; Matsumoto, Masaki; Nakata, Keiji*; Gonnokami, Kiyomi*; Toda, Rikiya*

JNC TN8430 2003-011, 56 Pages, 2004/01

JNC-TN8430-2003-011.pdf:2.07MB

The glove-box dismantling facility in the Plutonium Fuel Production Facility is developed to dismantle after-service glove-boxes with remote-controlled devices such as an arm-type manipulator. An abrasive wheel cutter, which is used to size reduce the gloveboxes, generates sparks during operation. This dispersing spark was a problem from the fire prevention point of view. A suitable spark control measures for this operation were required. We developed panels to minimize spark dispersion, shields to prevent the income of sparks to the pre-filter, and incombustible pre-filters. The equipment was tested and effectiveness was confirmed. This report provides the results of these tests.

Journal Articles

Improvement of neutron detection efficiency with high sensitive CR-39 track detector

Oda, Keiji*; Ichijo, H.*; Miyawaki, Nobumasa*; Yamauchi, Tomoya*; Nakane, Yoshihiro

Radiation Measurements, 34(1-6), p.171 - 175, 2001/06

 Times Cited Count:7 Percentile:50.11(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Outline of the Progress Report on Disposal Concept for TRU Waste in Japan

Hara, Keiji; Oda, Hideki*; Fujiwara, Hiroshi*; Tsukamoto, Masaki*; Mano, Tadashi

Genshiryoku Bakkuendo Kenkyu, 6(2), p.233 - 253, 2000/05

None

JAEA Reports

None

Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.

PNC TN8410 87-086VOL2, 944 Pages, 1986/09

PNC-TN8410-87-086VOL2.pdf:32.16MB

JAEA Reports

Detailed design of new material nitric acid recovery evaporator

Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.

PNC TN8410 87-086VOL1, 1037 Pages, 1986/09

PNC-TN8410-87-086VOL1.pdf:34.39MB

A detailed design for a New Material Nitric Acid Recovery Evaporator was carried out with a plan to use it to replace an already constructed stainless steel Nitric Acid Recovery Evaporator at the Power Reactor and Nuclear Fuel Development Corporation's Tokai Works. Most of the original Evaporator's conditions such as compliance with applicable laws, standards, structure, treatment performance and operating conditions were maintained when designing the new machine. The material is titanium with the addition of 5% tantalum. The Evaporator was designed with an operational life expectance of 10 years. We have calculated that the new Evaporator will have sufficient strength (including a seismatic design) and have the same evaporative performance as the already constructed one. During design, we referred to the results of already completed basic designs (Phase 1) of New Material Nitric Acid Recovery Evaporators, design and production of small-scale test equipment units, and the development of successful joints between different materials. We also considered manufacturing, installation, trial runs, maintenance, and the specifications for materials used for manufacturing, installation, piping and operation of the new Evaporator.

JAEA Reports

Engineering examination on the recovery of TBP from solvent waste for waste treatment plant

Itakura, Keiji*; Kuroda, Yasuo*; Kan, Yoshihiko*; Kobayashi, Shinichiro*; Ogi, Katsumi*; Nishijima, Naotaka*; Sato, Teruyoshi*

PNC TJ121 79-03, 111 Pages, 1979/02

PNC-TJ121-79-03.pdf:2.61MB

no abstracts in English

JAEA Reports

2nd power-up test for JRR-2

Kambara, Toyozo; Uno, Hidero; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Takayanagi, Hiroshi; Fujimura, Tsutomu; Morita, Morito; Ichihara, Masahiro; et al.

JAERI 1045, 11 Pages, 1963/03

JAERI-1045.pdf:0.72MB

no abstracts in English

53 (Records 1-20 displayed on this page)