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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
clusters (250 nm in dia.) embedded in background H gas with the J-KAREN laser (1 J, 40 fs, 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.
Sakaki, Hironao; Fukuda, Yuji; Nishiuchi, Mamiko; Jinno, Satoshi; Kanasaki, Masato; Yogo, Akifumi; Kondo, Kiminori; Saito, Fumihiro; Fukami, Tomoyo; Ueno, Masayuki; et al.
Progress in Nuclear Science and Technology (Internet), 4, p.182 - 185, 2014/04
The concept of a compact ion particle accelerator has become attractive in view of recent progress in laser-driven ions acceleration. In the development of many applications of laser-accelerated ions, it is necessary for securing the radiation safety to calculate the dose evaluation. The dose was measured with the radio-photoluminescent (RPL) glass dosimeter on the test beamline of at laser-driven accelerator. The Monte Carlo code, PHITS (Particle and Heavy Ion Transport code system) simulation is shown to be reasonably predictive at the test beamline for measured with the RPL glass dosimeter. We compare of the measured dose level on the laser-driven accelerator with the result of PHITS code in this report.
Yogo, Akifumi; Kondo, Kiminori; Mori, Michiaki; Kiriyama, Hiromitsu; Ogura, Koichi; Shimomura, Takuya; Inoue, Norihiro*; Fukuda, Yuji; Sakaki, Hironao; Jinno, Satoshi; et al.
Optics Express (Internet), 22(2), p.2060 - 2069, 2014/01
Times Cited Count：8 Percentile：47.84(Optics) clusters formed in a supersonic expansion of a gas mixtureJinno, Satoshi; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Kanasaki, Masato; Kondo, Kiminori; Faenov, A. Ya.*; Skobelev, I. Yu.*; Pikuz, T.; Boldarev, A. S.*; et al.
Optics Express (Internet), 21(18), p.20656 - 20674, 2013/09
Times Cited Count：19 Percentile：72.17(Optics)A detailed mathematical model is presented for a submicron-sized cluster formation in a binary gas mixture flowing through a three-staged conical nozzle. In order to experimentally confirm this model, the cluster sizes have been evaluated using the Mie scattering method, which is to measure the angular distribution of light scattered from targets. The mean sizes of CO clusters produced in the gas mixtures of CO(30%)/H(70%) and CO(10%)/He(90%) are estimated to be 0.28
0.03 
m and 0.260.04 m, respectively. In addition, total gas density profiles measured with an interferometer were found to be agreed with the numerical modeling within a factor of two. The dryness (
ratio) in the targets was found to support the numerical modeling. Thus, our mathematical model of cluster formation was proved to be reliable enough for the binary gas mixture by the experimental results.
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：0.05We 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.
clusters formed with a supersonic expansion of a mixed-gas using a three-staged nozzleJinno, Satoshi; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Kanasaki, Masato; Kondo, Kiminori; Faenov, A. Ya.*; Skobelev, I. Yu.*; Pikuz, T.; Boldarev, A. S.*; et al.
Applied Physics Letters, 102(16), p.164103_1 - 164103_4, 2013/04
Times Cited Count：22 Percentile：71.5(Physics, Applied)The size of CO clusters, produced in a supersonic expansion of a mixed-gas of CO/He or CO/H through a three-staged conical nozzle designed based on the Boldarev's model, has been evaluated by measuring the angular distribution of light scattered from the clusters. The data are analyzed utilizing the Mie scattering theory, and the sizes of CO clusters are estimated as 0.22 m and 0.25 m for the cases of CO/He and CO/H gas mixtures, respectively. The results confirm that the Boldarev's model is reliable enough for the production of micron-sized clusters.
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.
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 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 14.390.05 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.
Sakaki, Hironao; Kanasaki, Masato; Fukuda, Yuji; Nishiuchi, Mamiko; Hori, Toshihiko; Yogo, Akifumi; Jinno, Satoshi; Niita, Koji*
Review of Scientific Instruments, 84(1), p.013301_1 - 013301_7, 2013/01
Times Cited Count：5 Percentile：30.23(Instruments & Instrumentation)A single-shot-imaging thin scintillator film was developed for an online Thomson parabola (TP) spectrometer and the first analysis of laser accelerated ions, using the online TP spectrometer, was demonstrated at the JAEA-Kansai Advanced Relativistic Engineering Laser System (J-KAREN). An energy spectrum of 4.0 MeV protons is obtained using only this imaging film without the need of a microchannel plate that is typically utilized in online ion analyses. A general-purpose Monte Carlo particle and heavy ion-transport code system, which consists of various quantum dynamics models, was used for the prediction of the luminescent properties of the scintillator. The simulation can reasonably predict not only the ion trajectories detected by the spectrometer, but also luminescence properties.
Oka, Toshitaka; Jinno, Satoshi*; Fujinami, Masanori*
Analytical Sciences, 25(7), p.837 - 844, 2009/07
Times Cited Count：12 Percentile：15.38(Chemistry, Analytical)Positrons have been used for material analysis not only because of their novel characteristics, such as an ability to detect open-volume type defects in materials, but also because interactions with solids differ from those of electrons in such processes as scattering and diffraction. Monoenergetic positron beams and microbeams were developed in the 1980s, and positron experiments have made progress in material analyses. In this article we review the fundamental technique of microbeam fabrication, especially using a magnetically-guided positron beam, its extension to various analytical methods, and expectations for future research.
Oka, Toshitaka; Jinno, Satoshi*; Fujiwara, Aya*; Fujinami, Masanori*
no journal, ,
Temperature dependence of free volume in polyethylene was investigated by positron annihilation lifetime spectroscopy. The relationship between the thermal expansion of free volume and the sample density was clearly shown.
Fujinami, Masanori*; Jinno, Satoshi*; Oka, Toshitaka; Kawashima, Yuji*
no journal, ,
Sakaki, Hironao; Kanasaki, Masato; Fukuda, Yuji; Nishiuchi, Mamiko; Yogo, Akifumi; Jinno, Satoshi; Katagiri, Masaki*; Niita, Koji*
no journal, ,
A single-shot imaging thin scintillator film for online Thomson Parabola spectrometer (TP) has been developed, and the first diagnosis for laser-driven ion by the online TP is demonstrated at J-KAREN laser facility. The energy spectrum of 
4.0 MeV proton is obtained by only this imaging film without using Micro-Channel-Plate that is utilized on online ion diagnosis in general. The general-purpose Monte Carlo particle and heavy ion transport code systems (PHITS) consists various quantum dynamics models is used in the simulation of the scintillator's luminescent diagnostic. The simulation is reasonably predictive not only ion trajectories by the spectrometer but also the luminescence property.
Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Ogura, Koichi; Kondo, Kiminori; Oda, Keiji*; Yamauchi, Tomoya*
no journal, ,
Recently, solid state nuclear track detectors such as CR-39 detectors have been extensively used in laser-driven ion acceleration experiments, because CR-39 can record the tracks of ion clearly even in the intense fields of photons and high energy electrons. By analyzing the etch pit growth behavior, we can obtain not only the radial intensity distribution of ion beam, but the energy and nuclear species for each ion precisely. 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.
Hattori, Atsuto*; Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Ogura, Koichi; Kondo, Kiminori; Oda, Keiji*; et al.
no journal, ,
A precise measurement has been made utilizing a stacked CR-39 detectors for laser accelerated protons. The protons are accelerated from a thin polyimide target irradiated by intense Ti:sapphire laser (8 J energy and 40 fs duration). By analyzing the etch pits on the last layer of CR-39, the maximum proton energy is evaluated 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 the multi-step etching technique. The maximum energy of proton obtained is 14.390.05 MeV. This method allows us to measure the maximum energy of proton precisely, which is ten times higher than that of the conventional methods.
Kanasaki, Masato; Sakaki, Hironao; Fukuda, Yuji; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Ogura, Koichi; Kondo, Kiminori; Oda, Keiji*; Yamauchi, Tomoya*
no journal, ,
Recently, CR-39 track detectors have been extensively used in laser-driven ion acceleration experiments, because the CR-39 have a great advantage that they are insensitive to high energy photons and electrons and capable of detecting only ions. However, it is required that the real-time diagnosis systems for laser accelerated ions to increase the experimental efficiency with using high repetition Laser. We have demonstrated that the online measurement of laser accelerated ions with several-tens MeV by real-time Thomson parabola system, which are calibrated by CR-39, with thin luminescent single bunch profile monitor.
Fukuda, Yuji; Sakaki, Hironao; Kanasaki, Masato; Yogo, Akifumi; Jinno, Satoshi; Tampo, Motonobu; Faenov, A.*; Pikuz, T.; Hayashi, Yukio; Kando, Masaki; et al.
no journal, ,
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. This ion detection method is applied to laser-driven ion acceleration experiments using cluster-gas targets, and ion signals with energies up to 50 MeV per nucleon are identified.
Sakaki, Hironao; Fukuda, Yuji; Kanasaki, Masato; Jinno, Satoshi; Yogo, Akifumi; Nishiuchi, Mamiko; Kando, Masaki; Ueno, Masayuki; Fukami, Tomoyo; Niita, Koji*
no journal, ,
The compact ion particle accelerator has become attractive in view of recent progress in laser-driven ions acceleration. In the development of the instrument, it is necessary to do the bench-mark of the amount of the different types of radiation by the simulation code for radiation shieldings. The Monte Carlo Particle and Heavy Ion Transport code (PHITS) was used for bench-mark the dose on the laser-driven cluster-target type accelerator.
Kanasaki, Masato; Sakaki, Hironao; Fukuda, Yuji; Yogo, Akifumi; Jinno, Satoshi; Kondo, Kiminori; Akagi, Takashi*; Hattori, Atsuto*; Matsukawa, Kenya*; Oda, Keiji*; et al.
no journal, ,
In the laser-driven ion acceleration experiment, fast electrons and X-rays also generated and these particles could cause significant contaminants to the ion detectors an a background noise. In the present study, to minimize the noise signals, we have optimized thickness of ZnS(Ag) fluorescent screen, which is much sensitive for ions, through Monte Carlo particle transport code PHITS. And we have also evaluate the response of the fluorescent screen as a function of fluence using rf-accelerator.
Hattori, Atsuto*; Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Hori, Toshihiko; Kurashima, Satoshi; Kamiya, Tomihiro; Kondo, Kiminori; et al.
no journal, ,
PADC, poly(allyl diglycol carbonate), is well-known as CR-39 track detector and it performs the highest sensitivity for protons and heavy ions in track detectors. In order to diagnose ion beams precisely, we have to check environmental effect of irradiation for their sensitivity. Then, we have focused on the vacuum effect, which means that the storage of PADC in vacuum before and during irradiation decreases the track sensitivity. The vacuum effects had been studied on the case of protons and alpha-particles. In the present study, we have carried out quantitative evaluation of vacuum effect for carbon ion irradiation, and we have found the vacuum effect is also observed in the case of heavy ion irradiation.
