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Sako, Hiroyuki; Harada, Hiroyuki; Sakaguchi, Takao*; Chujo, Tatsuya*; Esumi, Shinichi*; Gunji, Taku*; Hasegawa, Shoichi; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; et al.
Nuclear Physics A, 956, p.850 - 853, 2016/12
Times Cited Count：12 Percentile：65.66(Physics, Nuclear)Nishiuchi, Mamiko; Sakaki, Hironao; Esirkepov, T. Z.; Nishio, Katsuhisa; Pikuz, T.*; Faenov, A.*; Skobelev, I. Yu.*; Orlandi, R.; Sako, Hiroyuki; Pirozhkov, A. S.; et al.
Physics of Plasmas, 22(3), p.033107_1 - 033107_8, 2015/03
Times Cited Count：71 Percentile：96.85(Physics, Fluids & Plasmas)Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.
Sako, Hiroyuki; Chujo, Tatsuya*; Gunji, Taku*; Harada, Hiroyuki; Imai, Kenichi; Kaneta, Masashi*; Kinsho, Michikazu; Liu, Y.*; Nagamiya, Shoji; Nishio, Katsuhisa; et al.
Nuclear Physics A, 931, p.1158 - 1162, 2014/11
Times Cited Count：23 Percentile：80.23(Physics, Nuclear)Recently, a heavy-ion program as a future J-PARC project has been discussed. The main goals of the program are to explore the QCD phase diagram at highbaryon density with heavy ions up to uranium at the beam energies of around 10A GeV. We are planning to focus on the electron and muon measurements and rare probe search such asmulti-strangeness and charmed hadrons with high beam rates at J-PARC. A heavy-ionacceleration scheme has been considered with a new heavy-ion linac and a new booster ring, with the existing 3-GeV Rapid-Cycling Synchrotron, and the 30-GeV Main Ring synchrotron. An overview of the heavy-ion program and accelerator design, as well as physics goals and conceptual design of the experiments are presented.
Sakaki, Hironao; Nishiuchi, Mamiko; Maeda, Shota; Sagisaka, Akito; Pirozhkov, A. S.; Pikuz, T.; Faenov, A.*; Ogura, Koichi; Fukami, Tomoyo; Matsukawa, Kenya*; et al.
Review of Scientific Instruments, 85(2), p.02A705_1 - 02A705_4, 2014/02
Times Cited Count：2 Percentile：11.24(Instruments & Instrumentation)High intensity laser-plasma interaction has attracted considerable interest for a number of years. The laser-plasma interaction is accompanied by generation of various charged particle beams. Results of simultaneous novel measurements of electron-induced photonuclear neutrons (photoneutron), which are a diagnostic of the laser-plasma interaction, are proposed to use for optimization of the laser-plasma ion generation. The proposed method is demonstrated by the laser irradiation with the intensity os 1
10
W/cm
on the metal foil target. The photoneutrons are measured by using NE213 liquid scintillation detectors. Heavy-ion signal is registered with the CR39 track detector simultaneously. The measured signals of the electron-induced photoneutrons are well reproduced by using the Particle and Heavy Ion Transport code System (PHITS). The results obtained provide useful approach for analyzing the various laser based ion beams.
Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Yamauchi, Kunihito; Shimada, Katsuhiro; Terakado, Tsunehisa; Matsukawa, Makoto; Hasegawa, Mitsuru*; Minato, Tsuneaki*; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.9501405_1 - 9501405_5, 2012/06
Times Cited Count：4 Percentile：29.2(Engineering, Electrical & Electronic)The withstand voltage of turn insulation is essential issues for the superconducting magnet. The actual turn voltage is larger than the turn voltage under the ideal condition because of the voltage fluctuations of the power supply and the resonance phenomenon in the magnet. In this paper, the voltage measurement of the JT-60U power supply and the resonance characteristics of the EF4 are described. The actual maximum turn voltage is almost same as the voltage under the ideal condition.
Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Hasegawa, Mitsuru*; Minato, Tsuneaki*; Sako, Katsuhisa*
no journal, ,
no abstracts in English
Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Sako, Hiroyuki; Pikuz, T.; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; Maeda, Shota; et al.
no journal, ,
The up-grade plan for the heavy ion accelerator facilities in the world is now going on. The important issues to be solved is how to make high-current, high Q/M and high energy heavy ion beam. To make smaller size heavy ion accelerator is important in order to minimize the construction and running costs. The key issue is, "whether or not we can obtain high Q/M ion beam at the very beginning of the accelerator stages". However, the existing conventional ion-source technology can supply the beam of Q/M 
0.2. On the other hand, our research at is to accelerate the ions by the laser-based method by using high contrast high intensity short pulse laser system, J-KAREN. Thanks to the extra-ordinary high quasi-static electric field of 
100 TV/m set in our method, the ions are efficiently stripped and accelerated toward high energy. By optimizing the condition, it is very probable that not only the laser-based ion source but also the laser-based ion injector would be realized. We show the experimental results of high-energy heavy ion acceleration by the interaction between high intensity short-pulse laser pulse interaction with the thin-foil target.
Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Sako, Hiroyuki; Orlandi, R.; Pikuz, T.; Faenov, A.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.
no journal, ,
To investigate the quark-gruon plasma or the systhesis of the super-heavy elements, the upgrade of the existing large accelerator facilities are going on. At J-PARC, the high flux high energy heavy ion beam is also desired. To have the beam, it is key issue how to obtain the high Q/M heavy ions a the ion source. However, the conventional ion source technique have difficulties to obtain such ions. On the other hand, we succeeded to obtain the high Q/M heavy ion beam with 
10 MeV/u from the interaction between the J-KAREN laser and thin foil target interaction. This results shows that the laser-driven ion acceleration scheme have possibility that it can substitute the conventional ion source as well as the injector.
Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Orlandi, R.; Sako, Hiroyuki; Pikuz, T.; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.
no journal, ,
For the applications of compact injector, we conduct the ion acceleration experiments using relatively compact and high-contrast short pulse laser system, J-KAREN at KPSI JAEA. The on-target laser intensity of 10 Wcm
with 200TW, less than 10J of energy, is achieved by controlling the temporal and spatial pulse profiles. Without applying plasma mirror system, the maximum proton energy of 43 MeV is obtained with aluminum (Al) 0.8 um thick target. In some shots we observe that the protons and Al ions are accelerated up to 30 MeV and 12 MeV/u, respectively. With the soft X-ray spectroscopy the Al ions are found to be almost fully stripped, which is caused by the synergy of three major effects: optical field ionization due to the laser and plasma collective fields; the electron impact ionization; and the X-ray single photon ionization. The observation of almost fully stripped Al ions proves that laser-driven ions acceleration is a promising ion source for the conventional accelerator. In addition, the observed energy of 12 MeV/u of the Al ions shows that the laser-based ion acceleration method can be the basis of a compact heavy ion injector for nuclear physics.
Wcm intensity high contrast laser pulses interacting with the thin foil targetNishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Orlandi, R.; Sako, Hiroyuki; Pikuz, T.; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.
no journal, ,
Laser-driven ion beam is paid attention because of its peculiar characteristics. One of the applications is the compact injector for the conventional accelerator system for the nuclear research. For that objective, we have carried out the J-KAREN experiment with 10 Wcm of intensity, less than 10 J of energy and 35fs of laser duration with 10
contrast level. The J-KAREN laser pulses are irradiated on the Al foil target. Almost fully stripped aluminum ion acceleration up to 12 MeV/u from the interaction between the ultra-intense short pulse high contrast laser and the micrometer thick foil target is presented.
Sakaki, Hironao; Nishiuchi, Mamiko; Esirkepov, T. Z.; Nishio, Katsuhisa; Pikuz, T. A.*; Faenov, A.*; Orlandi, R.; Pirozhkov, A. S.; Sako, Hiroyuki; Sagisaka, Akito; et al.
no journal, ,
The novel tool for the frontier of the exotic nucleus was proposed by fusing the high-intensity laser technology and the accelerator technology. We carried out its proof-of-concept experiments at the J-KAREN laser system. And, the iron which is simulated the produced exotic nucleus were extracted by the laser from aluminum membrane.
Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Orlandi, R.; Sako, Hiroyuki; Pikuz, T. A.*; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.
no journal, ,
The contemporary radiofrequency accelerator technology provides radio-isotope beams for the research. However, the existing technology now faces difficulties in exploring the further frontiers. One of the solutions might be brought by the combination of the state of the art high intensity short pulse laser system and the nuclear measurement technique. Recent progress of the laser technology brought table-top lasers with focused intensity up to 10 Wcm with only less than 10 J of energy on target. By the interaction with the solid density target, the laser can extract heavy ions in multi-charged state and low emittance, independently on the chemical properties of the target material. We propose Laser-driven Exotic Nuclei extraction-acceleration methods (LENex), in which the exotic nuclei which are the products in the target by the bombardment of the external ion beam, are extracted away by a femtosecond petawatt laser pulse in the form of highly-charged and high energy beam. As a proof-of-experiment of the LENex scheme, we demonstrate the extraction of the almost fully stripped iron ions with the energies of 0.9 GeV by J-KAREN laser system.
Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Orlandi, R.; Sako, Hiroyuki; Pikuz, T. A.*; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.
no journal, ,
The contemporary radiofrequency accelerator technology provides radio-isotope beams for the research. However, the existing technology now faces difficulties in exploring the further frontiers. One of the solutions might be brought by the combination of the state of the art high intensity short pulse laser system and the nuclear measurement technique. Recent progress of the laser technology brought table-top lasers with focused intensity up to 10 Wcm with only less than 10 J of energy on target. By the interaction with the solid density target, the laser can extract heavy ions in multi-charged state and low emittance, independently on the chemical properties of the target material. We propose Laser-driven Exotic Nuclei extraction-acceleration methods (LENex), in which the exotic nuclei which are the products in the target by the bombardment of the external ion beam, are extracted away by a femtosecond petawatt laser pulse in the form of highly-charged and high energy beam. As a proof-of-experiment of the LENex scheme, we demonstrate the extraction of the almost fully stripped iron ions with the energies of 0.9 GeV. by J-KAREN laser system.
Sako, Hiroyuki; Harada, Hiroyuki; Imai, Kenichi; Nagamiya, Shoji; Ozawa, Kyoichiro; Saha, P. K.; Nishio, Katsuhisa; Hwang, S.
no journal, ,
In heavy-ion collisions at 10 AGeV/c, the baryon density is expected to reach 10 times as high as the normal nucleus density. We are designing a spectrometer for a future heavy-ion experiment. We aim at observing directly the information on high baryon density in dilepton measurements. The spectrometer consists of a solenoid spectrometer which covers the backward acceptance at the polary angle larger than 30 degrees, and a dipole spectrometer which covers the polar angle less than 30 degrees. Hadrons will be identified by Time-of-flight counters, electrons will be identified by a Ring Imaging Cherencov Counters, photons will be identified by electromagnetic calorimeters, and muons will be measured by iron absorbers and trackers.
