Crystallization processes of quartz in a granitic magma; Implications for the magma chamber processes of Okueyama granite, Kyushu, Japan

Yuguchi, Takashi*; Kato, Takenori*; Ogita, Yasuhiro; Watanabe, Minori*; Yamazaki, Hayato*; Kato, Asuka*; Ito, Daichi*; Yokoyama, Tatsunori; Sakata, Shuhei*; Ono, Takeshi*

Journal of Asian Earth Sciences, 265, p.106091_1 - 106091_13, 2024/04

https://doi.org/10.1016/j.jseaes.2024.106091

Towards a novel laser-driven method of exotic nuclei extraction-acceleration for fundamental physics and technology

Nishiuchi, Mamiko*; Sakaki, Hironao*; Esirkepov, T. Zh.*; Nishio, Katsuhisa; Pikuz, T. A.*; Faenov, A. Ya.*; Skobelev, I. Yu.*; Orlandi, R.; Pirozhkov, A. S.*; Sagisaka, Akito*; et al.

Plasma Physics Reports, 42(4), p.327 - 337, 2016/04

https://doi.org/10.1134/S1063780X1604005X

A combination of a petawatt laser and nuclear physics techniques can crucially facilitate the measurement of exotic nuclei properties. With numerical simulations and laser-driven experiments we show prospects for the Laser-driven Exotic Nuclei extraction-acceleration method proposed in [M. Nishiuchi et al., Phys. Plasmas 22, 033107 (2015)]: a femtosecond petawatt laser, irradiating a target bombarded by an external ion beam, extracts from the target and accelerates to few GeV highly charged short-lived heavy exotic nuclei created in the target via nuclear reactions.

Laser-driven multi-charged heavy ion beam acceleration

Nishiuchi, Mamiko; Sakaki, Hironao; Esirkepov, T. Z.; Nishio, Katsuhisa; Pikuz, T. A.*; Faenov, A. Ya.*; Pirozhkov, A. S.; Sagisaka, Akito; Ogura, Koichi; Kanasaki, Masato; et al.

Research Using Extreme Light; Entering New Frontiers with Petawatt-Class Lasers II (Proceedings of SPIE, Vol.9515), p.95151D_1 - 95151D_4, 2015/06

https://doi.org/10.1117/12.2179204

Experimental demonstration of multi-charged heavy ion acceleration from the interaction between the ultra-intense short pulse laser system and the metal target is presented. The laser pulse of 10 J laser energy, 36 fs pulse width, and the contrast level of 10 from 200 TW class Ti:sapphire J-KAREN laser system at JAEA is used in the experiment. Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated. This is achieved by the high intensity laser field of 10Wcm interacting with the solid density target. The demonstrated iron ions with high charge to mass ratio (Q/M) is difficult to be achieved by the conventional heavy ion source technique in the accelerators.

Acceleration of highly charged GeV Fe ions from a low-Z substrate by intense femtosecond laser

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

https://doi.org/10.1063/1.4913434

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.

Chemical states of fallout radioactive Cs in the soils deposited at Fukushima Daiichi Nuclear Power Plant accident

Kozai, Naofumi; Onuki, Toshihiko; Arisaka, Makoto; Watanabe, Masayuki; Sakamoto, Fuminori; Yamasaki, Shinya; Jiang, M.

Journal of Nuclear Science and Technology, 49(5), p.473 - 478, 2012/05

https://doi.org/10.1080/00223131.2012.677131

Chemical states of radioactive Cs in the contaminated soils by Fukushima Daiichi Nuclear Power Plant accident has been characterized by the desorption experiments using appropriate reagents solutions and size fractionation of the contaminated soils. Approximately 70% of radioactive Cs in the residual fraction were associated with the size fractions larger than the elutriated one, even though mica-like minerals were contained in the elutriated one. These results strongly suggest that radioactive Cs was irreversibly associated with soil components other than mica like minerals in the contaminated soil.

Technical design of NBI system for JT-60SA

Ikeda, Yoshitaka; Akino, Noboru; Ebisawa, Noboru; Hanada, Masaya; Inoue, Takashi; Honda, Atsushi; Kamada, Masaki; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; et al.

Fusion Engineering and Design, 82(5-14), p.791 - 797, 2007/10

https://doi.org/10.1016/j.fusengdes.2007.05.077

Modification of JT-60U to a superconducting device (so called JT-60SA) has been planned to contribute to ITER and DEMO. The NBI system is required to inject 34 MW for 100 s. The upgraded NBI system consists of twelve positive ion based NBI (P-NBI) units and one negative ion based NBI (N-NBI) unit. The injection power of the P-NBI units are 2 MW each at 85 keV, and the N-NBI unit will be 10 MW at 500 keV, respectively. On JT-60U, the long pulse operation of 30 s at 2 MW (85 keV) and 20 s at 3.2 MW (320 keV) have been achieved on P-NBI and N-NBI units, respectively. Since the temperature increase of the cooling water in both ion sources is saturated within 20 s, further pulse extension up to 100 s is expected to mainly modify the power supply systems in addition to modification of the N-NBI ion source for high acceleration voltage. The detailed technical design of the NBI system for JT-60SA is presented.

Proof of principle experiment of Laser-driven Exotic Nuclei extraction-acceleration method

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.

Measurement of electron spectrum generated by irradiating thin-Foil target with Ultra-intense Ultra-short pulse laser

Maeda, Shota; Nishiuchi, Mamiko; Sakaki, Hironao; Sagisaka, Akito; Pirozhkov, A. S.; Pikuz, T.; Faenov, A. Ya.*; Ogura, Koichi; Fukuda, Yuji; Matsukawa, Kenya*; et al.

no journal, , 

In JAEA, the high energy ions generated by the interaction between Ultra-intense Ultra-Short pulse laser and thin-foil target is being studied. Irradiating condition must be optimized to generate higher energy ions while suppress the becoming gigantic of laser. It is necessary to know the physical phenomenon in plasma to determine the parameter to optimize from the information on the electron and neutron, X-rays, which are generated simultaneously with ion. In this study, in order to measure electron temperature accurately, an electron spectrometer was developed which have broad range (1-200 MeV). The detector is comprised of permanent magnets and a fluorescent plate, CCD camera. In the presentation, the result of the calibration experiment carried out using 4, 9, 12, 15 MeV quasi-monoenergetic electron beam in HIBMC will be reported. Moreover, response analysis method was inspected using PHITS which is particle transporting Monte Carlo simulation code, and will also report the result.

Ion acceleration by the 10 Wcm intensity high contrast laser pulses interacting with the thin foil target

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, , 

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.

Laser-driven ion acceleration by high intensity short-pulse high-contrast laser system at JAEA

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.