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Nakamoto, Tatsushi*; Ohata, Hirokatsu*; Ogitsu, Toru*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 31, 2007/02
Radiation resistance of organic materials used in superconducting magnets for a 50 GeV - 750 kW proton beam line for the J-PARC neutrino experiment was studied with respect to mechanical properties. Specimens cooled at a liquid nitrogen temperature of 77 K were irradiated by 
rays. The flexural strength of glass-fiber reinforced plastics (GFRPs), the tear strength of polyimide films and the tensile strength of adhesive films were evaluated. It was verified that the organic materials used in the superconducting magnets have the sufficient radiation resistance, and the degradation of thier mechanical properties after the 10 years operation was estimated to be negligible.
Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi; Nakamoto, Tatsushi*; Ogitsu, Toru*; Ohata, Hirokatsu*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 32, 2007/02
Radiation resistance of polymeric materials used in the superconducting magnets installed for the J-PARC neutrino beam line was studied with respect to gas evolution. The polymeric materials were irradiated by rays at 77K. It was found that hydrogen gas evolved mainly from the polymeric materials, and the amount of hydrogen from whole superconducting magnet system per 1 year was estimated to be 0.37mol. This amount of hydrogen is low enough to be removed by a hydrogen absorbing apparatus. Therefore, the influence of hydrogen evolved from the magnet system on the operation of the helium purifying system can be negligible.
Makida, Yasuhiro*; Ohata, Hirokatsu*; Okamura, Takahiro*; Ogitsu, Toru*; Nakamoto, Tatsushi*; Kimura, Nobuhiro*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 34, 2007/02
A string of superconducting magnets is to be set at an arc section of the J-PARC neutrino beam line. To keep the magnets at superconducting condition, a helium cryogenic facility is to be constructed. Parts of cryogenic devices are located beside the magnets, so thier resistance to radiation with predicted dose of 1 MGy in maximum must be assured. A cryogenic control valve is one of the active devices used in the radio-active area, and its radio-proof characteristics is improved by (1) exchaging intolerant materials by proof ones, (2) moving the feed back control circuit unit including electronics from the valve body to a low radio-active area. Two prototype valves, a tuning valve and a Gauzky relief valve, have been prepared and have been tested by using the Cobalt 60 irradiation facility in JAEA. Actual operations of the both prototypes have been checked at the irradiation test bench, and they were successfully operated after irradiation of 1 MGy.
-ray irradiation effects on polymeric materials in superconducting magnets for the J-PARC neutrino experiment, 2; Gas evolutionIdesaki, Akira; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi; Nakamoto, Tatsushi*; Ogitsu, Toru*; Ohata, Hirokatsu*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*
no journal, ,
Irradiation effect on polymeric materials used in the superconducting magnets for the J-PARC neutrino beam line was studied with respect to gas evolution. The polymeric materials were irradiated by -ray at 77K. It was found that hydrogen gas evolves mainly from the polymeric materials, and that the amount of hydrogen from whole superconducting magnet system per 1 year is 0.37mol. Furthermore, it was found that the amount of gas evolution increases with increasing in the storage time at room temperature after the irradiation at 77K.
-ray irradiation effects on polymeric materials in superconducting magnets for the J-PARC neutrino experiment, 1; Mechanical propertiesIdesaki, Akira; Nakamoto, Tatsushi*; Ogitsu, Toru*; Ohata, Hirokatsu*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi
no journal, ,
Radiation resistance of polymeric materials used in superconducting magnets for a 50 GeV-750 kW proton beam line for the J-PARC neutrino experiment was studied with respect to mechanical properties. Specimens were irradiated by rays with the maximum dose beyond 10 MGy. It was verified that the polymeric materials have the sufficient radiation resistance, and the degradation of their mechanical properties after the 10 years operation was estimated to be negligible.
-ray irradiation effects on polymeric materials in superconducting magnets; Gas evolutionIdesaki, Akira; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi; Nakamoto, Tatsushi*; Ogitsu, Toru*; Ohata, Hirokatsu*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*
no journal, ,
Irradiation effect on polymeric materials used in the superconducting magnets for the J-PARC neutrino beam line was studied with respect to gas evolution. The polymeric materials were irradiated by -ray at 77K. It was found that hydrogen gas evolves mainly from the polymeric materials, and that the amount of hydrogen from whole superconducting magnet system per 1 year is 0.37 mol.
-ray irradiation effects on polymeric materials in superconducting magnets; Mechanical propertiesNakamoto, Tatsushi*; Ohata, Hirokatsu*; Ogitsu, Toru*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi
no journal, ,
A Superconducting magnet system will be adopted for the J-PARC neutrino beam line. GFRPs whose matrices are phenol resin and epoxy resin, and polyimides are used as structural materials and electrical insulation. Radiation resistance of these polymeric materials is very important, because they are exposed to high radiation field. In this work, specimens were irradiated by rays with the maximum dose beyond 10 MGy at liquid nitrogen temperature (77K), and the mechanical properties were investigated. It was verified experimentally that the polymeric materials have sufficient radiation resistance for the using in the J-PARC neutrino beam line.
Makida, Yasuhiro*; Ohata, Hirokatsu*; Okamura, Takahiro*; Ogitsu, Toru*; Nakamoto, Tatsushi*; Kimura, Nobuhiro*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio
no journal, ,
A Superconducting magnet system will be adopted for the J-PARC neutrino beam line. Since the magnet system will be exposed to high radiation field, the radiation resistance of a cryostat is very important. We have developed radio-proof control valve and relief valve by selection of some parts and separation of the positioner. In this work, the developed valves were worked under the ray irradiation, and it was found that the valves show the radiation resistance above 1 MGy.
Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Takeda, Osamu; Ito, Hisayoshi; Kusano, Joichi
no journal, ,
It is required for various apparatus used in the tunnel of J-PARC accelerator to possess radiation resistance. A halogen-free and flame retardant cable will be adopted for the power cable. However, there are little reports about the radiation resistance of halogen-free and flame retardant cables. In this work, the irradiation effect on thermal degradation behavior of the materials in flame retardant cables. It was found that starting temperature of thermal degradation of sheath material sifts to lower temperature and temperature range of water evolution from flame retardant agent sifts to higher temperature by irradiation.
Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Oshima, Takeshi; Koizumi, Norikiyo; Sugimoto, Makoto; Okuno, Kiyoshi
no journal, ,
A laminated material composed of glass cloth/polyimide film/epoxy resin will be used as an insulating material for superconducting coil of ITER. In order to keep safe and stable operation of the superconducting coil system, it is indispensable to evaluate radiation resistance of the material, because the material is exposed to high radiation field of 10MGy at low temperature of 4K. In this work, the gas evolution from the laminated material by ray irradiation at liquid nitrogen temperature (77K) was investigated, and the difference of gas evolution behavior due to difference of components in the epoxy resin was discussed. As a result, it was found that the main gases from the epoxy resin by the irradiation were hydrogen, carbon monoxide and carbon dioxide, and that the amount of the gases from epoxy resin containing cyanate ester was 30-40% less than that from the epoxy resin containing tetraglycidyl-diaminophenylmethane (TGDDM).
-ray irradiation test of instrumentation and operational amplifier for remote maintenance system of ITERTakeda, Nobukazu; Kakudate, Satoshi; Oyake, Noriyuki; Nakahira, Masataka; Shibanuma, Kiyoshi; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Baba, Shinji*; Okamoto, Hiroki*; et al.
no journal, ,
no abstracts in English
