Development of remote sensing technique using radiation resistant optical fibers under high-radiation environment

Ito, Chikara; Naito, Hiroyuki; Ishikawa, Takashi; Ito, Keisuke; Wakaida, Ikuo

JPS Conference Proceedings (Internet), 24, p.011038_1 - 011038_6, 2019/01

https://doi.org/10.7566/JPSCP.24.011038

A high-radiation resistant optical fiber has been developed in order to investigate the interiors of the reactor pressure vessels and the primary containment vessels at the Fukushima Daiichi Nuclear Power Station. The tentative dose rate in the reactor pressure vessels is assumed to be up to 1 kGy/h. We developed a radiation resistant optical fiber consisting of a 1000 ppm hydroxyl doped pure silica core and 4 % fluorine doped pure silica cladding. We attempted to apply the optical fiber to remote imaging technique by means of fiberscope. The number of core image fibers was increased from 2000 to 22000 for practical use. The transmissive rate of infrared images was not affected after irradiation of 1 MGy. No change in the spatial resolution of the view scope by means of image fiber was noted between pre- and post-irradiation. We confirmed the applicability of the probing system, which consists of a view scope using radiation-resistant optical fibers.

Control of divertor heat load by Ar injection with keeping high performance in ELMy H-mode plasmas on JT-60U

Higashijima, Satoru; Asakura, Nobuyuki; Kubo, Hirotaka; Miura, Yukitoshi; Nakano, Tomohide; Konoshima, Shigeru; Itami, Kiyoshi; Sakurai, Shinji; Takenaga, Hidenobu; Tamai, Hiroshi; et al.

Journal of Nuclear Materials, 313-316, p.1123 - 1130, 2003/03

https://doi.org/10.1016/S0022-3115(02)01502-7

Reduction of steady-state heat load in the divertor and transient one by ELMs is a crucial issue for tokamak fusion devices. High radiation loss power is necessary for the heat load reduction, and the conventional gas puffing can increase the density and the radiation loss power, but it degrades the confinement. Core plasma with high confinement should be maintained simultaneously. Impurity seeding is a secure way to enhance the radiation loss power. In JT-60U, heat load is successfully reduced by Ar injection with keeping a high confinement in ELMy H-mode plasmas. In this paper, heat load reduction, radiation enhancement, and change of ELM activity are discussed.

Experimental study on heat transfer characteristics of a high-temperature gas-gas heat exchanger with helically coiled tube bundles

Inagaki, Yoshiyuki; ; Ioka, Ikuo;

Proc. of ASMEJSME 4th Int. Conf. on Nuclear Engineering 1996 (ICONE-4), 1(PART B), p.633 - 637, 1996/00

no abstracts in English

Study of impurity and radiative losses in divertor plasmas with absolutely calibrated VUV spectrometers in JT-60U

Kubo, Hirotaka; Sugie, Tatsuo; Shimada, Michiya; Hosogane, Nobuyuki; Sakasai, Akira; Tsuji, Shunji; Itami, Kiyoshi; Asakura, Nobuyuki; Shimizu, Katsuhiro

Nuclear Fusion, 33(10), p.1427 - 1433, 1993/00

https://doi.org/10.1088/0029-5515/33/10/I02

no abstracts in English

Magnetization of ceramic Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O after neutron irradiation

Takamura, Saburo; Sekino, Hajime; ; ; Hoshiya, Taiji; ;

Japanese Journal of Applied Physics, 30(1A), p.L18 - L20, 1991/01

https://doi.org/10.1143/JJAP.30.L18

no abstracts in English

Radiation Loss and Global Energy Balance of Ohmically Heated Divertor Discharge in JT-60 Tokamak

; ; Yoshida, H.; Nakamura, H.; ;

JAERI-M 86-056, 13 Pages, 1986/03

JAERI-M-86-056.pdf:0.5MB

no abstracts in English

High Temperature Mechanical Properties of Neutron Irradiated Zircaloy-4

;

JAERI-M 83-068, 18 Pages, 1983/04

JAERI-M-83-068.pdf:1.0MB

no abstracts in English

Improvement of plasma parameters by titanium gettering in the JFT-2M tokamak

; ; ; ; ; ; ; ; ; ; et al.

Journal of Nuclear Materials, 76-77, p.581 - 586, 1978/00

https://doi.org/10.1016/0022-3115(78)90211-8

no abstracts in English

Preparation of Polyethylene with Low Dielectric Loss by Radiation-Induced Polymerization of Ethylene in 2.2.4-Trimethyl Pentane

; ; Takehisa, Masaaki; Machi, Sueo

JAERI-M 5500, 5 Pages, 1973/12

JAERI-M-5500.pdf:0.21MB

no abstracts in English