Measurement of thermal contact conductance between round-shaped superconducting wires and rectangular slot in copper block for application to cryogenic transfer tube.pdfVIP

International Journal of Heat and Mass Transfer 103 (2016) 165–172 Contents lists available at ScienceDirect International Journal of Heat and Mass Transfer journal homepage: /locate/ijhmt Measurement of thermal contact conductance between round-shaped superconducting wires and rectangular slot in copper block for application to cryogenic transfer tube Taekyung Ki a,?, Makoto Yoshida b, Ye Yang a,c, Toru Ogitsu a, Nobuhiro Kimura a, Tatsushi Nakamoto a, Yasuhiro Makida b, Masami Iio a a Applied Research Laboratory, KEK (High Energy Accelerator Research Organization), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan b Institute of Particle and Nuclear Studies, KEK (High Energy Accelerator Research Organization), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan c Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka 819-0395, Japan article info Article history: Received 1 April 2016 Received in revised form 31 May 2016 Accepted 7 July 2016 Available online 28 July 2016 Keywords: Round-shaped superconducting wire, Thermal contact conductance Transfer tube Cryogenics Thermal joint abstract At J-PARC (Japan Proton Accelerator Research Complex), the COMET (Coherent Muon to Electron Transition) experiment is being prepared. Pion-capture and muon-transport superconducting solenoid magnets will be used to capture pions and transport muons which are produced by pion decays. Since the radiation level is high near the magnets, a cold box and a current lead box, which supply a twophase forced helium ?ow and currents to the magnets, will be located apart from the magnets. To connect the cold box and current lead box to the magnets, unique cryogenic transfer tubes that have thermal joints for installing NbTi superconducting lead wires at the insides of the transfer tubes are necessary. The transfer tubes should be able to make the wires thermally stable. In this paper, thermal contact conductance between three round-shaped NbTi/Cu monol