Direct energy conversion using Ni/SiC Schottky junction in Np and Am gamma ray regions

Fukuda, Tatsuo; Kobata, Masaaki; Shobu, Takahisa; Yoshii, Kenji; Kamiya, Junichiro; Iwamoto, Yosuke; Makino, Takahiro*; Yamazaki, Yuichi*; Oshima, Takeshi*; Shirai, Yasuhiro*; et al.

Journal of Applied Physics, 132(24), p.245102_1 - 245102_8, 2022/12

https://doi.org/10.1063/5.0099136

Direct energy conversion has been investigated using Ni/SiC Schottky junctions with the irradiation of monochromatized synchrotron X-rays simulating the gamma rays of Np (30 keV) and Am (60 keV). From current-voltage measurements, electrical energies were obtained for both kinds of gamma rays. The energy conversion efficiencies were found to reach up to 1.6%, which is comparable to those of a few other semiconducting systems reported thus far. This result shows a possibility of energy recovery from nuclear wastes using the present system, judging from the radiation tolerant nature of SiC. Also, we found different conversion efficiencies between the two samples. This could be understandable from hard X-ray photoelectron spectroscopy and secondary ion mass spectroscopy measurements, suggesting the formation of Ni-Si compounds at the interface in the sample with a poor performance. Hence, such combined measurements are useful to provide information that cannot be obtained by electrical measurements alone.

Oxidative decomposition of ammonium ion with ozone in the presence of cobalt and chloride ions for the treatment of radioactive liquid waste

Aihara, Haruka; Watanabe, So; Shibata, Atsuhiro; Mahardiani, L.*; Otomo, Ryoichi*; Kamiya, Yuichi*

Progress in Nuclear Energy, 139, p.103872_1 - 103872_9, 2021/09

https://doi.org/10.1016/j.pnucene.2021.103872

baking method for degassing of a kicker magnet in accelerator beam line

Kamiya, Junichiro; Ogiwara, Norio; Yanagibashi, Toru*; Kinsho, Michikazu; Yasuda, Yuichi*

Journal of Vacuum Science and Technology A, 34(2), p.021604_1 - 021604_10, 2016/03

https://doi.org/10.1116/1.4941369

In this study, we propose a new degassing method by which only kicker magnets in the accelerator beam line are baked out without raising the temperature of the vacuum chamber to prevent unwanted heat expansion of the chamber. The bake-out system comprises the heater and thermal radiation shield plates, which are installed between the kicker magnet and the chamber wall. The result of the verification test showed that each part of the kicker magnet was heated to above the target temperature with a small rise in the vacuum chamber temperature. A graphite heater was selected in this application to bake-out the kicker magnet in the beam line to ensure reliability and easy maintainability of the heater. The vacuum characteristics of graphite were suitable for heater operation in the beam line. A preliminary heat-up test conducted in the accelerator beam line also showed that each part of the kicker magnet was successfully heated and that heat expansion of the chamber was negligibly small.

Development of microbeam formation and single-ion hit technologies at the TIARA cyclotron

Yokota, Wataru; Sato, Takahiro; Kamiya, Tomihiro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Funayama, Tomoo; Sakashita, Tetsuya; et al.

JAEA-Technology 2014-018, 103 Pages, 2014/09

JAEA-Technology-2014-018.pdf:123.66MB

The world's first microbeam focusing technology for heavy ions of hundreds MeV accelerated by a cyclotron has been developed at the TIARA facility in the Takasaki Advanced Radiation Research Institute of the Japan Atomic Energy Agency. The technology enables us to form a microbeam of less than 1 m in diameter and to shoot a specified point on a target by one ion (single-ion hit) with spatial accuracy of microbeam size. In the course of the development, a cyclotron technology to accelerate a small energy-spread beam of hundres MeV, which is necessary for focusing to 1 m, has been developed as well as a beam focusing apparatus, beam size measurement and so forth based on the several-MeV microbeam/single-ion hit system of the TIARA electrostatic accelerators. Applicability of the technologies was examined by actual use in irradiation experiment and the result were fed back to them. This paper reports the process and the results of the development over ten years.

Study on ferromagnetic ordering of FeRh thin films induced by energetic heavy ion irradiation by means of X-ray magnetic circular dichroism

Aiko, Kazuma*; Toki, Atsushi*; Okuda, Shuichi*; Saito, Yuichi; Kamiya, Tomihiro; Nakamura, Tetsuya*; Kinoshita, Toyohiko*; Iwase, Akihiro*; Matsui, Toshiyuki*

Nuclear Instruments and Methods in Physics Research B, 314, p.99 - 102, 2013/11

https://doi.org/10.1016/j.nimb.2013.05.031

Reduction of charging effects on negative secondary ion TOF mass spectra of PMMA using cluster ion impacts

Hirata, Koichi*; Saito, Yuichi; Chiba, Atsuya; Yamada, Keisuke; Narumi, Kazumasa; Kamiya, Tomihiro

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 165, 2013/01

https://doi.org/10.11484/jaea-review-2012-046

MFM and PEEM observation of micrometre-sized magnetic dot arrays fabricated by ion-microbeam irradiation in FeRh thin films

Aiko, Kazuma*; Toki, Atsushi*; Matsui, Toshiyuki*; Iwase, Akihiro*; Sato, Takahiro; Takano, Katsuyoshi*; Koka, Masashi; Saito, Yuichi; Kamiya, Tomihiro; Okochi, Takuo*; et al.

Journal of Synchrotron Radiation, 19(2), p.223 - 226, 2012/03

https://doi.org/10.1107/S0909049511054057

Micrometer-sized magnetic patterning of FeRh films using an energetic ion microbeam

Fujita, Naoki*; Matsui, Toshiyuki*; Kosugi, Shinya*; Sato, Takahiro; Saito, Yuichi; Takano, Katsuyoshi; Koka, Masashi; Kamiya, Tomihiro; Seki, Shu*; Iwase, Akihiro*

Japanese Journal of Applied Physics, 49(6), p.060211_1 - 060211_3, 2010/06

https://doi.org/10.1143/JJAP.49.060211

Status of accelerators and technical development at TIARA

Yokota, Wataru; Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; et al.

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.22 - 24, 2008/08

no abstracts in English

High-resolution beam energy-spread measurements using combination of nuclear resonant reactions and a 0 beam line separation

Ishii, Yasuyuki; Chiba, Atsuya; Uno, Sadanori; Saito, Yuichi; Mizuhashi, Kiyoshi; Tajima, Satoshi*; Kamiya, Tomihiro

Nuclear Instruments and Methods in Physics Research B, 260(1), p.15 - 19, 2007/07

https://doi.org/10.1016/j.nimb.2007.01.273

Measurement of beam energy spreads caused by an accelerator are needed to evaluation the choromatic aberration when ion beams with micorometer or nanometer sizes are formed at a focusing point. A measurement method of the beam energy spreads without using a analyzing magnet with a high resolution was developed to evaluate the chromatic aberration in a light-ion micorbeam system connected to the 3MV JAEA single-ended accelerator. The accurate beam energy spread measurement method within a resolution of 10 was developed using resonance nuclear reactions with narrow energy spreads of A(p,)Si and Mg(p,)A in a MeV energy range. Furthermore, ion species separating method, in a 0-degree beam line connected to the accelerator, was developed using parmanent magnets attached on the accelerator tube in the accelerator. The two kinds of developmet resulted in measuring baem energy spreads generated from the accelerator directly.