Control of the size of etchable ion tracks in PVDF; Irradiation in an oxygen atmosphere and with fullerene C

Kitamura, Akane; Yamaki, Tetsuya*; Yuri, Yosuke*; Koshikawa, Hiroshi*; Sawada, Shinichi*; Yuyama, Takahiro*; Usui, Aya; Chiba, Atsuya*

Nuclear Instruments and Methods in Physics Research B, 460, p.254 - 258, 2019/12

https://doi.org/10.1016/j.nimb.2019.06.030

Poly(vinylidene-fluoride) (PVDF) film is suitable for investigation of the size of etchable ion tracks because we can clearly judge the finish of the track etching and the surrounding bulk area remains due to the high chemical stability. Thereby we can measure the radius of ion tracks of each ion. In this study, we focused on two irradiation conditions for controlling the size of etchable ion tracks of PVDF films. One was irradiation in an oxygen atmosphere and the other was a fullerene (C) cluster beam irradiation. SEM observation showed that the size of pores became larger by irradiation in an oxygen atmosphere. It was found that the oxidation of ion tracks widened the size of etchable ion tracks. The C irradiation caused larger etchable tracks on the PVDF surface. The result could represent the effect of local and simultaneous collisions by the swift aggregated ions.

Simultaneous measurement of neutron-induced fission and capture cross sections for Am at neutron energies below fission threshold

Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Nishinaka, Ichiro*; Ota, Shuya*; Nagayama, Tatsuro*; Tamura, Nobuyuki*; Goto, Shinichi*; Andreyev, A. N.; Vermeulen, M. J.; et al.

Nuclear Instruments and Methods in Physics Research A, 856, p.133 - 138, 2017/06

https://doi.org/10.1016/j.nima.2016.12.021

Dismantlement of large fusion experimental device JT-60U

Ikeda, Yoshitaka; Okano, Fuminori; Sakasai, Akira; Hanada, Masaya; Akino, Noboru; Ichige, Hisashi; Kaminaga, Atsushi; Kiyono, Kimihiro; Kubo, Hirotaka; Kobayashi, Kazuhiro; et al.

Nihon Genshiryoku Gakkai Wabun Rombunshi, 13(4), p.167 - 178, 2014/12

https://doi.org/10.3327/taesj.J14.007

The JT-60U torus was disassembled so as to newly install the superconducting tokamak JT-60SA torus. The JT-60U used the deuterium for 18 years, so the disassembly project of the JT-60U was the first disassembly experience of a fusion device with radioactivation in Japan. All disassembly components were stored with recording the data such as dose rate, weight and kind of material, so as to apply the clearance level regulation in future. The lessons learned from the disassembly project indicated that the cutting technologies and storage management of disassembly components were the key factors to conduct the disassembly project in an efficient way. After completing the disassembly project, efforts have been made to analyze the data for characterizing disassembly activities, so as to contribute the estimation of manpower needs and the radioactivation of the disassembly components on other fusion devices.

Identified charged hadron production in collisions at = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

https://doi.org/10.1103/PhysRevC.83.064903

Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

A Broad-band RF buncher cavity using finemet cut cores for ion beams

Watanabe, Masao; Chiba, Yoshiaki*; Koseki, Tadashi*; Katayama, Takeshi*; Oshiro, Yukimitsu*; Watanabe, Shinichi*

Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004) (CD-ROM), 3 Pages, 2005/00

A broad-band rf cavity as a buncher of ion beams has been developed. Operating frequencies of the cavity is between 18 and 45 MHz. The cavity was installed in the beam transport line of the Hi-ECR ion source system in CNS for the beam test. Beam structure of 30 MHz was successfully observed for 10 keV proton beam.

Laser detection of surface acoustic waves as a method of measuring an Ar ion beam modification of carbon thin film

Kitazawa, Shinichi; Putra, P.; Sakai, Seiji; Narumi, Kazumasa; Naramoto, Hiroshi; Yamamoto, Shunya; Chiba, Atsuya

Nuclear Instruments and Methods in Physics Research B, 206, p.952 - 955, 2003/05

https://doi.org/10.1016/S0168-583X(03)00868-1

Pulsed energy impacts are expected to generate the elastic waves reflecting the elastic properties of impacted substances. Among the generated waves, the surface acoustic waves (SAW) can be more specific to the surface structures and can be used effectively in the characterization of thin films in a non-destructive way. In the present study, pulsed laser impacts were employed to generate SAWs on a thin film and the SAWs are detected with a laser reflection technique. To test the effectiveness of this method, an amorphous carbon films were irradiated with 13 keV Ar ions at room temperature in a broad range and the SAW propagation velocity was evaluated as a function of Ar ion dose. The present preliminary experiment using pulsed laser suggests the successful detection of SAW from typical substances with different modulus of elasticity such as fcc metals, oxides and semi conducting materials.

Diagnostics system of JT-60U

Sugie, Tatsuo; Hatae, Takaki; Koide, Yoshihiko; Fujita, Takaaki; Kusama, Yoshinori; Nishitani, Takeo; Isayama, Akihiko; Sato, Masayasu; Shinohara, Koji; Asakura, Nobuyuki; et al.

Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.482 - 511, 2002/09

https://doi.org/10.13182/FST02-A242

The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so that the internal structure of plasmas has been explored. The understanding of plasma confinement has been enhanced by density and temperature fluctuation measurements using a mm-wave reflectometer and electron cyclotron emission measurements respectively. In addition, the real-time control experiments of electron density, neutron yield, radiated power and electron temperature gradient have been carried out successfully by corresponding diagnostic devices. These measurements and the real time control contribute to improving plasma performance. Diagnostic devices for next generation fusion devices such as a CO2 laser interferometer/polarimeter and a CO2 laser collective Thomson scattering system have been developed.

Infrated laser polarimetry for electron density pleasurement in tokamak plasmas

Kawano, Yasunori; Chiba, Shinichi; Inoue, Akira*

Review of Scientific Instruments, 72(1), p.1068 - 1072, 2001/01

https://doi.org/10.1063/1.1321743

no abstracts in English

Analysis of neutron spectra from thick targets bombarded with 710-MeV particles by quantum molecular dynamics plus statistical decay model

Meigo, Shinichiro; Chiba, Satoshi; Shin, Kazuo*

Journal of Nuclear Science and Technology, 36(3), p.250 - 255, 1999/03

https://doi.org/10.3327/jnst.36.250

no abstracts in English

Dual CO laser polarimeter for Faraday rotation measurement in tokamak plasmas

Kawano, Yasunori; Chiba, Shinichi; Shirai, Hiroshi; *; Nagashima, Akira

Review of Scientific Instruments, 70(1), p.714 - 717, 1999/01

https://doi.org/10.1063/1.1149470

no abstracts in English