Identification of hydrogen species on Pt/AlO by inelastic neutron scattering and their reactivity with ethylene

Yamazoe, Seiji*; Yamamoto, Akira*; Hosokawa, Saburo*; Fukuda, Ryoichi*; Hara, Kenji*; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Tsukuda, Tatsuya*; Yoshida, Hisao*; Tanaka, Tsunehiro*

Catalysis Science & Technology, 11(1), p.116 - 123, 2021/01

https://doi.org/10.1039/D0CY01968B

Quasi-monochromatic pencil beam of laser-driven protons generated using a conical cavity target holder

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

https://doi.org/10.1063/1.3697843

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.

Development of chemical decontamination method for old Waste Treatment Facility

Fukuda, Seiji; Kondo, Hitoshi; Okubo, Toshiyuki

JNC TN9410 2004-010, 56 Pages, 2004/03

JNC-TN9410-2004-010.pdf:1.53MB

The Old Waste Treatment Facility of JOYO(0ld JWTF), operation of which stopped in 1995, is scheduled to be dismantled starting in 2010. In order to reduce worker's radiation exposure, it is necessary to reduce radiation dose rate of the main equipments by system chemical decontamination before dismantling. In thjs research, the decontamination solutions were selected in view of reduction of consequential waste amount and expense of treatment of decontamination waste. We evaluated decontamination factor (DF) in test with contaminated samples (Hot test). Moreover we performed a conceptual design of the decontamination system using the decontamination solution that obtained the highest DF in hot test. The solution selected in hot test did not achieve the target DF to all equipments. For some equipment more aggressive solutions, which dissolve contaminants and base metal, would be needed, however using these solutions would tend to increase consequential waste amount and expense of treatment of decontamination waste. Therefore, we evaluated the dissolution rate of these solutions for stainless steels in test with non-contaminated samples (Cold test). The main result of obtaining through the hot test and the cold test is shown below.(1)By alternating immersions in sodium hydroxide solution and nitric acid, the highest DF was obtained. (Maximum of DF=10.7, 80 deg-C). (2)The decontamination system is composed of two decontamination solution tanks, a washing water tank, a pump that supplies decontamination solutions and washing water, and filters for removing contaminants. (3)The test samples were immersed in various solutions (HN03 + HF, HCl, H2S04) for 24 hours at room temperature. As a result, it was confirmed that the dissolution rate of HN03 + HF is remarkably large compared with other solutions (7.43 micro-m/day).

Evaluation on radioactive waste for the decommissioning of deuterium critical assembly(DCA)

Konno, Shotaro; Fukuda, Seiji; ; Hazama, Taira; ; Hashimoto, Makoto

JNC TN9410 2002-015, 59 Pages, 2002/10

JNC-TN9410-2002-015.pdf:2.3MB

Deuterium critical assembly (DCA) is a critical facility with 1 kW maximum thermal output reached its initial criticality in 1969. DCA operations were stopped on 26 September 2001, then it has been planed to submit a legal application for decommissioning of DCA to MEXT and to shift to decommissioning phase. In this work, we have evaluated the calculation value of neutron flux by comparison with an actual measurement in biological shield and the amount of contaminated radioactive materials etc. to make a document on estimation of the inventories and the wastes quantity etc. in the legal application. Results are as follows. (1)Fast, epithermal and thermal neutron flux calculated have exceeded the measurement data at almost all location. Therefore concentration of activated materials calculated by neutron flux calculation value is estimated higher than actual that. (2)The amount of radioactive materials that contaminated by nuclides other than tritium is estimated about 3.0 10Bq. The concentration of tritium-contaminated radioactive materials is estimated about 4.110Bq/g at the maximum in concrete, about 7.6 10Bq/g in the surface of aluminum plumbing. (3)Consequential waste quantity (solid waste) to radioactive waste generated in total process of dismantling is estimated about 30ton. As for Radioactive liquid waste quantity, moderator for specimen is estimated about 1.4m , consequential liquid wastes is estimated about 300m. (4)The amount of Tritium generated in dismantling (radioactive gas waste) is estimated about 7.2510Bq in dismantling of heavy water system facility, measurement control system facility and neutron reactor.

Results of the H-mode experiments with outer and lower divertors

Nakamura, Hiroo; Tsuji, Shunji; ; Ozeki, Takahisa; Ishida, Shinichi; Azumi, Masafumi; Akiba, Masato; Ando, Toshiro; Fujii, Tsuneyuki; Fukuda, Takeshi; et al.

JAERI-M 89-106, 52 Pages, 1989/08

JAERI-M-89-106.pdf:1.27MB

no abstracts in English

Radiation monitoring of JRR-2 during its experiment and power-up test

Fukuda, Seiji; Kato, Jinzo; Onishi, Takeshi; Watanabe, Kozo; Okubo, Katsuichi; Ouchi, Masafusa; Isozaki, Hiroshi; Seki, Mamoru; Mito, Norio; Tsuruo, Akira; et al.

JAERI 1028, 55 Pages, 1962/10

JAERI-1028.pdf:4.9MB

no abstracts in English

Laser-driven proton generation from a thin-foil target with a high-intensity laser

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

no journal, , 

High-intensity laser and thin-foil interactions produce high-energy particles, hard X-ray, high-order harmonics, and terahertz radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical and other applications. We have performed several high intensity laser-matter interaction experiments using a thin-foil target irradiated by Ti:sapphire laser (J-KAREN) at JAEA. The pulse duration was typically 40 fs (FWHM). The electron density profiles of the preformed plasma were observed with the interferometer. The high temporal contrast laser system could reduce the preformed plasma. The maximum proton energy gradually increased as the laser performance improved and finally protons of 40 MeV energy were observed at the peak laser intensity of 1 10 W/cm.

Proton acceleration with the thin-foil target at KPSI

Nishiuchi, Mamiko; Ogura, Koichi; Tanimoto, Tsuyoshi*; Pirozhkov, A. S.; Sakaki, Hironao; Fukuda, Yuji; Kanasaki, Masato; Kando, Masaki; Esirkepov, T. Z.; Sagisaka, Akito*; et al.

no journal, , 

We present the extension of the maximum energy of protons from the interaction between the short-pulse compact laser system and solid thin-foil target. The laser pulses with parameters of 800 nm in wavelength, 40 fs of pulse width, 7 J of energy, 10 contrast are focused onto the target with the peak intensity of more than 10 Wcm, which is also well confirmed by the measured electron temperature of 16 MeV. We report about the acceleration mechanism as well as future prospect on the proton acceleration experiment at JAEA.

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.