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Journal Articles

Possible observation of transverse laser cooled ultimate cold ion beam in S-LSR

Jimbo, Koichi*; Soda, Hikaru*; Yuri, Yosuke; Tongu, Hiromu*; Nakao, Masao*; Shirai, Toshiyuki*; Noda, Akira*

Proceedings of 25th North American Particle Accelerator Conference (NA-PAC '13) (Internet), p.886 - 888, 2013/09

Journal Articles

Approach to the low temperature state oriented for crystalline beam

Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Tongu, Hiromu*; Jimbo, Koichi*; Okamoto, Hiromi*; Osaki, Kazuya*; Yuri, Yosuke; Meshkov, I.*; Smirnov, A.*; et al.

Proceedings of 23rd Russian Particle Accelerator Conference (RuPAC 2012) (Internet), p.48 - 52, 2012/09

Journal Articles

Effectiveness of carbon-ion beams for apoptosis induction in rat primary immature hippocampal neurons

Kaminuma, Takuya*; Suzuki, Yoshiyuki*; Shirai, Katsuyuki*; Mizui, Toshiyuki*; Noda, Shinei*; Yoshida, Yukari*; Funayama, Tomoo; Takahashi, Takeo*; Kobayashi, Yasuhiko; Shirao, Tomoaki*; et al.

Journal of Radiation Research, 51(6), p.627 - 631, 2010/11

 Times Cited Count:8 Percentile:62.84(Biology)

Journal Articles

Measured and simulated transport of 1.9 MeV laser-accelerated proton bunches through an integrated test beam line at 1 Hz

Nishiuchi, Mamiko; Sakaki, Hironao; Hori, Toshihiko; Bolton, P.; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Mori, Michiaki; Orimo, Satoshi; Pirozhkov, A. S.; et al.

Physical Review Special Topics; Accelerators and Beams, 13(7), p.071304_1 - 071304_7, 2010/07

 Times Cited Count:25 Percentile:16.46(Physics, Nuclear)

A laser-driven repetition-rated 1.9 MeV proton beam line composed of permanent quadrupole magnets (PMQs), a radio frequency (rf) phase rotation cavity, and a tunable monochromator is developed to evaluate and to test the simulation of laser-accelerated proton beam transport through an integrated system for the first time. In addition, the proton spectral modulation and focusing behavior of the rf phase rotationcavity device is monitored with input from a PMQ triplet. In the 1.9 MeV region we observe very weakproton defocusing by the phase rotation cavity. The final transmitted bunch duration and transverse profile are well predicted by the PARMILA particle transport code. The transmitted proton beam duration of 6 ns corresponds to an energy spread near 5% for which the transport efficiency is simulated to be 10%. The predictive capability of PARMILA suggests that it can be useful in the design of future higher energy transport beam lines as part of an integrated laser-driven ion accelerator system.

Journal Articles

Laser-driven proton accelerator for medical application

Nishiuchi, Mamiko; Sakaki, Hironao; Hori, Toshihiko; Bolton, P.; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Mori, Michiaki; Orimo, Satoshi; Pirozhkov, A. S.; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.88 - 90, 2010/05

The concept of a compact ion particle accelerator has become attractive in view of recent progress in laser-driven ion acceleration. We report here the recent progress in the laser-driven proton beam transport at the Photo Medical Research Center (PMRC) at JAEA, which is established to address the challenge of laser-driven ion accelerator development for ion beam cancer therapy.

Journal Articles

Redox equilibria of the U$$^{4+}$$/U$$^{3+}$$ and U$$^{3+}$$/U couples in molten LiCl-RbCl eutectic

Nagai, Takayuki; Uehara, Akihiro*; Fujii, Toshiyuki*; Shirai, Osamu*; Sato, Nobuaki*; Yamana, Hajimu*

Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 77(8), p.614 - 616, 2009/08

 Times Cited Count:11 Percentile:70.95(Electrochemistry)

Formal redox potentials of the U$$^{4+}$$/U$$^{3+}$$ and U$$^{3+}$$/U couples in molten LiCl-RbCl eutectic were determined by cyclic voltammetry. These redox potentials were more negative than those in the LiCl-KCl eutectic but positive comparing to those in the NaCl-CsCl eutectic. This relation would be correlated with the averaged alkali cation radius.

Journal Articles

Ion acceleration using temporally-controlled high-intensity laser pulses

Yogo, Akifumi; Daido, Hiroyuki; Mori, Michiaki; Kiriyama, Hiromitsu; Bulanov, S. V.; Bolton, P.; Esirkepov, T. Z.; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; et al.

Reza Kenkyu, 37(6), p.449 - 454, 2009/06

The acceleration of protons driven by a high-intensity laser is comprehensively investigated via control of the target density by using ASE just before the time of the main-laser interaction. Two cases were investigated for which the ASE intensity differed by three orders of magnitude: In the low contrast case the beam centre for higher energy protons is shifted closer to the laser-propagation direction of 45$$^{circ}$$, while the center of lower-energy beam remains near the target normal direction. Particle-in-cell simulations reveal that the characteristic proton acceleration is due to the quasistatic magnetic field on the target rear side with the magnetic pressure sustaining a charge separation electrostatic field.

Journal Articles

Redox equilibria of Pu$$^{4+}$$/Pu$$^{3+}$$ and PuO$$_{2}$$$$^{2+}$$/Pu$$^{4+}$$ couples in molten NaCl-CsCl eutectic as measured by absorption spectrophotometry

Nagai, Takayuki; Uehara, Akihiro*; Fujii, Toshiyuki*; Shirai, Osamu*; Myochin, Munetaka; Yamana, Hajimu*

Radiochimica Acta, 97(4-5), p.209 - 212, 2009/05

 Times Cited Count:3 Percentile:72.48(Chemistry, Inorganic & Nuclear)

Redox behavior of uranium and plutonium in molten salts is the essential information for establishing an effective reprocessing process with spent MOX fuel. In an oxide electro-winning reprocessing process, the spent nuclear fuel is dissolved into the molten NaCl-CsCl eutectic, and the dissolved U(VI) and Pu(VI) species are reduced to be dioxides by electrolysis. In the present study, formal redox potentials of the Pu$$^{4+}$$/Pu$$^{3+}$$ and PuO$$_{2}$$$$^{2+}$$/Pu$$^{4+}$$ couples in the molten NaCl-CsCl eutectic at 923 K were determined. The fractions of Pu$$^{3+}$$, Pu$$^{4+}$$, and PuO$$_{2}$$$$^{2+}$$ were determined by UV/Vis/NIR absorption spectrophotometry. PuO$$_{2}$$ was dissolved into the molten NaCl-CsCl eutectic by Cl$$_{2}$$$$_{2}$$ gas purging. Valences of plutonium (Pu$$^{0}$$, Pu$$^{3+}$$, Pu$$^{4+}$$, and PuO$$_{2}$$$$^{2+}$$) were controlled by changing the flow rates of Cl$$_{2}$$, O$$_{2}$$, and Ar gases.

Journal Articles

Redox equilibria of the U$$^{4+}$$/U$$^{3+}$$ and U$$^{3+}$$/U couples in molten LiCl-RbCl eutectic

Nagai, Takayuki; Uehara, Akihiro*; Fujii, Toshiyuki*; Shirai, Osamu*; Sato, Nobuaki*; Yamana, Hajimu*

Proceedings of 2008 Joint Symposium on Molten Salts (USB Flash Drive), p.927 - 932, 2008/10

Formal redox potentials of the U$$^{4+}$$/U$$^{3+}$$ and U$$^{3+}$$/U couples in molten LiCl-RbCl eutectic were determined by cyclic voltammetry. These redox potentials were more negative than those in the LiCl-KCl eutectic but approximately similar to those in the NaCl-CsCl eutectic. These redox potentials in molten alkali chlorides would be correlated with the averaged alkali cationic radius of the melt.

Journal Articles

New method to measure the rise time of a fast pulse slicer for laser ion acceleration research

Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Nishiuchi, Mamiko; Ogura, Koichi; Orimo, Satoshi; Ma, J.*; Sagisaka, Akito; Kanazawa, Shuhei; Kondo, Shuji; et al.

IEEE Transactions on Plasma Science, 36(4), p.1872 - 1877, 2008/08

 Times Cited Count:7 Percentile:67.52(Physics, Fluids & Plasmas)

A dependence of cut-off proton kinetic energy on laser prepulse duration has been observed. ASE pedestal duration is controlled by a fast electro-optic pulse slicer where the risetime is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this risetime using a stretched, frequency chirped pulse.

Journal Articles

Simultaneous proton and X-ray imaging with femtosecond intense laser driven plasma source

Orimo, Satoshi; Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Ogura, Koichi; Sagisaka, Akito; Li, Z.*; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.

Japanese Journal of Applied Physics, Part 1, 46(9A), p.5853 - 5858, 2007/09

 Times Cited Count:15 Percentile:45.25(Physics, Applied)

A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Titanium Sapphire laser. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of $$sim$$10$$mu$$m, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.

Journal Articles

Characterization of an intense laser-produced preformed plasma for proton generation

Sagisaka, Akito; Daido, Hiroyuki; Ogura, Koichi; Orimo, Satoshi; Hayashi, Yukio; Mori, Michiaki; Nishiuchi, Mamiko; Yogo, Akifumi; Kado, Masataka; Fukumi, Atsushi*; et al.

Journal of the Korean Physical Society, 51(1), p.442 - 446, 2007/07

 Times Cited Count:1 Percentile:88.48(Physics, Multidisciplinary)

The recent progress of the laser driven accelerators which include high power laser driven electrons and ions are reviewed. The studies at JAEA Kansai are mainly described. Based on the recent progres, the various aspects of the applications are also reviewed.

Journal Articles

Beam cooling experiment at ion storage ring, S-LSR

Shirai, Toshiyuki*; Tanabe, Mikio*; Soda, Hikaru*; Ikegami, Masahiro*; Fujimoto, Shinji*; Tongu, Hiromu*; Noda, Akira*; Noda, Koji*; Shibuya, Shinji*; Fujimoto, Tetsuya*; et al.

Proceedings of 9th Symposium on Accelerator and Related Technology for Application, p.19 - 22, 2007/06

Journal Articles

Development of the irradiation method for the first instar silkworm larvae using locally targeted heavy-ion microbeam

Fukamoto, Kana; Shirai, Koji*; Sakata, Toshiyuki*; Sakashita, Tetsuya; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; Kakizaki, Takehiko; Shimura, Sachiko*; Kobayashi, Yasuhiko; et al.

Journal of Radiation Research, 48(3), p.247 - 253, 2007/05

 Times Cited Count:16 Percentile:49.86(Biology)

To carry out the radio-microsurgery study using silkworm, ${it Bombyx mori}$, we have already developed the specific irradiation systems for eggs and third to fifth instar larvae. In this study, a modified application consisting of the first instar silkworm larvae was further developed using heavy-ion microbeams. This system includes aluminum plates with holes specially designed to fix the first instar silkworm larvae during irradiation, and Mylar films were used to adjust energy deposited for planning radiation doses at certain depth. Using this system, the suppression of abnormal proliferation of epidermal cells in the knob mutant was examined. Following target irradiation of the knob-forming region at the first instar stage with 180-mum-diameter microbeam of 220 MeV carbon ($$^{12}$$C) ions, larvae were reared to evaluate the effects of irradiation. The results indicated that the knob formation at the irradiated segment was specially suppressed in 5.9, 56.4, 66.7 and 73.6 % of larvae irradiated with 120, 250, 400 and 600 Gy, respectively, but the other knob formations at the non-irradiated segments were not suppressed in either irradiation. Although some larva did not survive undesired non-targeted exposure, our present results indicate that this method would be useful to investigate the irradiation effect on a long developmental period of time. Moreover, our system could also be applied to other species by targeting tissues, or organs during development and metamorphosis in insect and animals.

Journal Articles

Laser prepulse dependency of proton-energy distributions in ultraintense laser-foil interactions with an online time-of-flight technique

Yogo, Akifumi; Daido, Hiroyuki; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Sagisaka, Akito; Pirozhkov, A. S.; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; et al.

Physics of Plasmas, 14(4), p.043104_1 - 043104_6, 2007/04

 Times Cited Count:57 Percentile:9.47(Physics, Fluids & Plasmas)

Fast protons are observed by a newly-developed $textit{online}$ time-of-flight spectrometer, which provides $textit{shot-to-shot}$ proton-energy distributions immediately after the irradiation of a laser pulse having an intensity of $$sim 10^{18}$$ W/cm$$^2$$ onto a 5-$$mu$$m-thick copper foil. The maximum proton energy is found to increase when the intensity of a fs-prepulse arriving 9 ns before the main pulse increases from 10$$^{14}$$ to 10$$^{15}$$ W/cm$$^2$$. Interferometric measurement indicates that the preformed-plasma expansion at the front surface is smaller than 15 $$mu$$m, which corresponds to the spatial resolution of the diagnostics. This sharp gradient of the plasma makes a beneficial effect on increasing the absorption efficiency of the main-pulse energy, resulting in the increase in the proton energy. This is supported by the result that the X-ray intensity from the laser plasma clearly increases with the prepulse intensity.

Journal Articles

High quality laser-produced proton beam generation by phase rotation

Noda, Akira*; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; Tongu, Hiromu*; Soda, Hikaru*; Daido, Hiroyuki; Mori, Michiaki; Kado, Masataka; Sagisaka, Akito; et al.

International Journal of Modern Physics B, 21(3&4), p.319 - 330, 2007/02

Laser ion production has been studied for downsizing of the accelerator dedicated for cancer therapy. For optimization of various parameters such as pre-pulse condition, target position, laser spot size on target, laser pulse width and so on, time of flight (TOF) measurement utilizing the detected signal by a plastic scintillation counter played an essential role for real time measurement. Protons up to 900 keV and 600 keV are produced from the thin foil targets of Ti 3 micron and 5 micron in thickness, respectively. Modification of the energy distribution of the laser-produced ions with Maxwell distribution by utilizing an RF electric field synchronized to the pulse laser, which is the rotation of the ion beam in the longitudinal phase space (phase rotation), has been demonstrated for the first time.

Journal Articles

Research into the radiosensitivity of normal brain tissue

Suzuki, Yoshiyuki*; Yoshida, Yukari*; Shirai, Katsuyuki*; Hamada, Nobuyuki*; Mizui, Toshiyuki*; Noda, Shinei*; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko; Shirao, Tomoaki*; et al.

JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 107, 2007/02

Journal Articles

Regeneration mechanism of hemopoietic organs in the silkworm, ${it Bombyx mori}$, after heavy-ion irradiation; Analysis by transplantation of the irradiated organs using a transgenic silkworm strain

Kiguchi, Kenji*; Shirai, Koji*; Sakata, Toshiyuki*; Fukamoto, Kana; Kakizaki, Takehiko; Wada, Seiichi*; Sakashita, Tetsuya; Funayama, Tomoo; Hamada, Nobuyuki*; Kobayashi, Yasuhiko

JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 117, 2007/02

no abstracts in English

Journal Articles

Development of laser driven proton sources and their applications

Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Mori, Michiaki; Ma, J.-L.; Pirozhkov, A. S.; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

Proceedings of 7th Pacific Rim Conference on Lasers and Electro-Optics (CLEO-PR 2007) (CD-ROM), p.77 - 79, 2007/00

We are developing a proton accelerator using an intense lasers with a focused intensity of $$>$$ 10$$^{17}$$ W/cm$$^{2}$$. To monitor proton energy spectra as well as plasma parameters at each laser shot, we are using real time detectors. The proton energy of MeV is stably obtained for applications.

Journal Articles

${it In-situ}$ measurement of UO$$_{2}$$$$^{2+}$$ concentration in molten NaCl-2CsCl by differential pulse voltammetry

Nagai, Takayuki; Uehara, Akihiro*; Fujii, Toshiyuki*; Shirai, Osamu*; Yamana, Hajimu*

Journal of Nuclear Science and Technology, 43(12), p.1511 - 1516, 2006/12

 Times Cited Count:6 Percentile:55.07(Nuclear Science & Technology)

In order to assess the applicability of Differential Pulse Voltammetry technique to the ${it In-situ}$ measurement of UO$$_{2}$$$$^{2+}$$ concentration in the oxide electro-winning process, DPV measurements for UO$$_{2}$$Cl$$_{2}$$ in molten NaCl-2CsCl were studied. DPV measurement of UO$$_{2}$$$$^{2+}$$ in NaCl-2CsCl at 923 K, with a set of optimized parameters (potential sweep rate -0.1 V/s, pulse cycle 0.1 s, pulse width 10 ms, and pulse potential height 50 mV), showed a clear current peak at -0.9 V vs. Cl$$_{2}$$/Cl$$^{-}$$, and it was attributed to the reduction of UO$$_{2}$$$$^{2+}$$ to UO$$_{2}$$$$^{+}$$. The relation between the current peak height and the analytical concentration of the UO$$_{2}$$$$^{2+}$$ showed good proportionality in the concentration region up to 0.06 mol/${it l}$, and the applicability of UO$$_{2}$$$$^{2+}$$ concentration measurement by DPV was confirmed up to 0.4 mol/${it l}$. In order to assess the interference by the coexisting fission product elements to the measurement of UO$$_{2}$$$$^{2+}$$ concentration, DPV measurements of UO$$_{2}$$$$^{2+}$$ concentration in molten NaCl-2CsCl containing PdCl$$_{2}$$, NdCl$$_{3}$$, SmCl$$_{3}$$, and CeCl$$_{3}$$ were performed also. Even before removing Pd, the current peak at -0.9 V vs. Cl$$_{2}$$/Cl$$^{-}$$ by the reduction of UO$$_{2}$$$$^{2+}$$ to UO$$_{2}$$$$^{+}$$ was found to be distinguishable from the reduction currents of Pd$$^{2+}$$ to Pd at -0.7 V vs. Cl$$_{2}$$/Cl$$^{-}$$. As a result, the applicability of DPV measurement technique to the ${it In-situ}$ monitoring of UO$$_{2}$$$$^{2+}$$ concentration in oxide electro-winning method is proposed.

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