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Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Tanimoto, Tsuyoshi*; Sagisaka, Akito*; Esirkepov, T. Z.; Kando, Masaki; Shizuma, Toshiyuki; Hayakawa, Takehito; Kiriyama, Hiromitsu; et al.
Optics Letters, 37(14), p.2868 - 2870, 2012/07
Times Cited Count：83 Percentile：95.88(Optics)Using high contrast (10
:1) and high intensity (10
W/cm
) laser pulse with the duration of 40 fs from OPCPA/Ti:Sapphire laser, a 40 MeV proton bunch is obtained, which is a record for laser pulse with energy less than 10 J. The efficiency for generation of protons with kinetic energy above 15 MeV is 0.1%.
Nishiuchi, Mamiko; Pirozhkov, A. S.; Sakaki, Hironao; Ogura, Koichi; Esirkepov, T. Z.; Tanimoto, Tsuyoshi; Kanasaki, Masato; Yogo, Akifumi; Hori, Toshihiko; Sagisaka, Akito; et al.
Physics of Plasmas, 19(3), p.030706_1 - 030706_4, 2012/03
Times Cited Count：6 Percentile：25.74(Physics, Fluids & Plasmas)A 7 MeV proton beam collimated to 16 mrad containing more than 
particles is experimentally demonstrated by focusing a 2J, 60 fs pulse of a Ti:sapphire laser onto targets of different materials and thicknesses placed in a millimeter scale conical holder. The electric potential induced on the target holder by laser-driven electrons accelerates and dynamically controls a portion of a divergent quasi-thermal proton beam originated from the target, producing a quasi-monoenergetic "pencil" beam.
Nishiuchi, Mamiko; Ogura, Koichi; Pirozhkov, A. S.; Tanimoto, Tsuyoshi; Yogo, Akifumi; Sakaki, Hironao; Hori, Toshihiko; Fukuda, Yuji; Kanasaki, Masato; Sagisaka, Akito; et al.
Proceedings of SPIE Europe Optics + Optoelectronics 2011, Vol.8079, 7 Pages, 2011/04
Times Cited Count：0 Percentile：0.01(Optics)Because of the peculiar characteristics of the laser-driven proton beam, many potential applications are proposed including establishing compact medical accelerator for the cancer therapy. For our final destination to establish the compact laser-driven proton accelerator, the experiments are performed to investigate proton and ion acceleration from thin foil targets, using a high contrast, ultra-short laser pulse from the J-KAREN laser at the Japan Atomic Energy Agency. The P-polarized laser pulse with the parameters of 800 nm, 40 fs, 4J, and with extremely high ASE contrast of 10
is focused onto the thin-foil targets with variable materials and thicknesses ranging from 100 um to sub-um. The achieved peak intensity is 
10
Wcm
. The maximum proton energy is reached to 14 MeV. The number of 
10 MeV protons is enough to carry 2 Gy dose onto the skin of the mouse within 10min with 10 Hz operation. This enables us to carry out in-vivo test instead of in-vitro test.
Kuramitsu, Yasuhiro*; Nakanii, Nobuhiko*; Kondo, Kiminori; Sakawa, Yoichi*; Mori, Yoshitaka*; Miura, Eisuke*; Tsuji, Kazuki*; Kimura, Kazuya*; Fukumochi, Shuji*; Kashihara, Mamoru*; et al.
Physical Review E, 83(2), p.026401_1 - 026401_6, 2011/02
Times Cited Count：16 Percentile：65.74(Physics, Fluids & Plasmas)An energy distribution function of energetic particles in the universe or cosmic rays is well represented by a power-law spectrum, therefore, nonthermal acceleration is essential to understand the origin of cosmic rays. A possible candidate for the origin of cosmic rays is wakefield acceleration at relativistic astrophysical perpendicular shocks. Substituting an intensive laser pulse for the large amplitude light waves, we performed a model experiment of the shock environments in a laboratory plasma.
Kuramitsu, Yasuhiro*; Nakanii, Nobuhiko*; Kondo, Kiminori; Sakawa, Yoichi*; Mori, Yoshitaka*; Miura, Eisuke*; Tsuji, Kazuki*; Kimura, Kazuya*; Fukumochi, Shuji*; Kashihara, Mamoru*; et al.
Physics of Plasmas, 18(1), p.010701_1 - 010701_4, 2011/01
Times Cited Count：19 Percentile：62.41(Physics, Fluids & Plasmas)Substituting an intensive laser pulse for the large amplitude light waves, we performed a model experiment of the shock environments in a laboratory plasma. An intensive laser pulse was propagated in a plasma tube created by imploding a hollow polystyrene cylinder, as the large amplitude light waves propagated in the upstream plasma at an astrophysical shock. Nonthermal electrons were generated, and the energy distribution functions of the electrons have a power-law component with an index of 2.
Tampo, Motonobu; Awano, Shinya*; Bolton, P.; Kondo, Kiminori; Mima, Kunioki*; Mori, Yoshitaka*; Nakamura, Hirotaka*; Nakatsutsumi, Motoaki*; Stephens, R. B.*; Tanaka, Kazuo*; et al.
Physics of Plasmas, 17(7), p.073110_1 - 073110_5, 2010/07
Times Cited Count：12 Percentile：42.46(Physics, Fluids & Plasmas)Nakamura, Hirotaka*; Chrisman, B.*; Tanimoto, Tsuyoshi*; Borghesi, M.*; Kondo, Kiminori; Nakatsutsumi, Motoaki*; Norimatsu, Takayoshi*; Tampo, Motonobu; Tanaka, Kazuo*; Yabuuchi, Toshinori*; et al.
Physical Review Letters, 102(4), p.045009_1 - 045009_4, 2009/01
Times Cited Count：23 Percentile：73.4(Physics, Multidisciplinary)Interactions between a relativistic-intensity laser pulse and a cone-wire target are studied by changing the focusing point of the pulse. The pulse, when focused on the sidewall of the cone, produced superthermal electrons with an energy 10 MeV, whereas less energetic electrons 1 MeV were produced by the pulse when focused on the cone tip. Efficient heating of the wire was indicated by significant neutron signals observed when the pulse was focused on the tip. Particle-in-cell simulation results show reduced heating of the wire due to energetic electrons produced by specularly reflected light at the sidewall.
Nakanii, Nobuhiko*; Kondo, Kiminori; Kuramitsu, Yasuhiro*; Mori, Yoshitaka*; Miura, Eisuke*; Tsuji, Kazuki*; Kimura, Kazuya*; Fukumochi, Shuji*; Kashihara, Mamoru*; Tanimoto, Tsuyoshi*; et al.
Applied Physics Letters, 93(8), p.081501_1 - 081501_3, 2008/08
Times Cited Count：4 Percentile：18.78(Physics, Applied)Energetic electrons were generated by the interaction of a high-intensity laser pulse with a plasma preformed from a hollow plastic cylinder via laser-driven implosion. The spectra of a comparatively high-density plasma had a bump around 10 MeV. Simple numerical calculations explained the spectra obtained in this experiment. This indicates that the plasma tube has sufficient potential to convert a Maxwellian spectrum to a comparatively narrow spectrum.
Abe, Hiroshi; ; *; *; *; *; Kaneta, Takayoshi*; *; Suzuki, Hiromitsu; Tani, Norio; et al.
JAERI-Research 97-068, 51 Pages, 1997/10
JAERI-Research-97-068.pdf:1.78MB
no abstracts in English
Tanimoto, Tsuyoshi; Sakaki, Hironao; Nishiuchi, Mamiko; Fukuda, Yuji; Hori, Toshihiko; Nishio, Katsuhisa; Kondo, Kiminori
no journal, ,
no abstracts in English
Tanimoto, Tsuyoshi; Nishiuchi, Mamiko; Kanasaki, Masato; Pirozhkov, A. S.; Tampo, Motonobu; Yogo, Akifumi; Ogura, Koichi; Hori, Toshihiko; Sagisaka, Akito; Fukuda, Yuji; et al.
no journal, ,
no abstracts in English
Nishiuchi, Mamiko; Pirozhkov, A. S.; Ogura, Koichi; Tanimoto, Tsuyoshi; Sakaki, Hironao; Hori, Toshihiko; Sagisaka, Akito; Yogo, Akifumi; Fukuda, Yuji; Kanasaki, Masato; et al.
no journal, ,
We present the results of the experiment of laser-driven proton acceleration with the interaction between laser and thin foil target. The maximum energy of the laser-driven protons increases as the intensity of the laser increases. In order to accelerate the proton beam toward higher energy with the limited energy of laser, we need to increase the intensity of the laser. For that purpose, we upgraded the laser mirrors in the beam line. As a result the intensity of the laser increases about one oreder of magnitude. With the tape target, we obtain proton beam whose maximum energy is 23 MeV. We also conducted the plasma mirror to increase the contrast of the laser. We show the detail of the proton acceleration results with the plasma mirror.
Nishiuchi, Mamiko; Pirozhkov, A. S.; Ogura, Koichi; Tanimoto, Tsuyoshi; Sakaki, Hironao; Hori, Toshihiko; Sagisaka, Akito; Yogo, Akifumi; Fukuda, Yuji; Kanasaki, Masato; et al.
no journal, ,
We present the results of the experiment of laser-driven proton acceleration by the interaction between laser and thin foil target. The maximum energy of the laser-driven protons increases as the intensity of the laser increases. In order to accelerate the proton beam toward higher energy with the limited energy of laser, we need to increase the intensity of the laser. For that purpose, we upgraded the laser mirrors in the beam line. As a result the intensity of the laser increases about one oreder of magnitude. With the tape target, we obtain proton beam whose maximum energy is 23 MeV. We also conducted the plasma mirror to increase the contrast of the laser. We show the detail of the proton acceleration results with the plasma mirror and nano-meter target.
Tanimoto, Tsuyoshi; Nishiuchi, Mamiko; Kanasaki, Masato; Pirozhkov, A. S.; Tampo, Motonobu; Yogo, Akifumi; Ogura, Koichi; Hori, Toshihiko; Sagisaka, Akito; Fukuda, Yuji; et al.
no journal, ,
no abstracts in English
Kanasaki, Masato; Yamauchi, Tomoya*; Nishiuchi, Mamiko; Pirozhkov, A. S.; Sakaki, Hironao; Ogura, Koichi; Tanimoto, Tsuyoshi; Yogo, Akifumi; Hori, Toshihiko*; Sagisaka, Akito; et al.
no journal, ,
A precise energy measurement for the laser-driven proton beam has been performed by utilizing stacked CR-39 covered with 13-
m thick aluminum filter. The proton beam was generated by exposing a thin foil target to an intense femtosecond laser pulse from the J-KAREN laser system. By analyzing the etch pit growth curves with multi-step etching technique. It, it is found that the maximum energy of the proton beam was evaluated ten times more precise than that by using the conventional time-of-flight (TOF) method.
Tanimoto, Tsuyoshi; Nishiuchi, Mamiko; Mishima, Yosuke*; Kikuyama, Kenshiro*; Morioka, Tomoya*; Morita, Kiyoshi*; Kanasaki, Masato; Pirozhkov, A. S.; Yogo, Akifumi; Ogura, Koichi; et al.
no journal, ,
Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Tanimoto, Tsuyoshi; Sagisaka, Akito; Esirkepov, T. Z.; Kando, Masaki; Kiriyama, Hiromitsu; Kanazawa, Shuhei; Kondo, Shuji; et al.
no journal, ,
no abstracts in English
Nishiuchi, Mamiko; Pirozhkov, A. S.; Sakaki, Hironao; Ogura, Koichi; Esirkepov, T. Z.; Tanimoto, Tsuyoshi; Yogo, Akifumi; Hori, Toshihiko; Sagisaka, Akito; Fukuda, Yuji; et al.
no journal, ,
We have successfully accelerate quasi-mono-energetic collimated 7MeV proton beam bt the interaction between the 2J 60fs Ti Sappire laser pulses with the thin-foil target on the target holder with conical cavity. The focusing and energy selection is by the E-field induced along the surface of the conical cavity by the point charge brought away by the escape electrons.
Tanimoto, Tsuyoshi; Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Kondo, Kiminori
no journal, ,
no abstracts in English
Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Tanimoto, Tsuyoshi; Sagisaka, Akito; Esirkepov, T. Z.; Shizuma, Toshiyuki; Hayakawa, Takehito; Hajima, Ryoichi; Kando, Masaki; et al.
no journal, ,
We demonstrated the energetic proton generation using 40 fsec intense Ti:Sapphire laser pulses. By drastically increasing the interaction intensity approximately 1E21 W/cm with keeping a ultra high contrast of 1E10:1, even without using plasma mirror, over 40 MeV protons were detected with 800 nm thick Al foil.
