Superconducting particle detectors are promising for Time-Of-Flight Mass Spectrometry of large molecules. The operating temperature of detectors is 0.3 K. To realize fast read-out and no-crosstalk, coaxial cables made of low-thermal conductivity alloys are needed between 0.3 K and room temperature. As the thermal conductivity of alloys used at low temperature is reported to differ by mechanical treatments, processed cables have to be measured. Wemeasured thermal conductivity of thin processed cables between 0.3 and 4.5 K, and observed a difference of 40% from literature in measurements of 70—30 CuNi. From present results,we realized implementation of cryogenic wiring between a large-scale array detector, which is placed on a cold stage at 0.3 K, and electronics at room temperature. I—V characteristics and signals from superconducting detectors were successfully observed.

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We have some problems concerning the measurement of thermal conductivity of thermal insulation. One of them is that there are few reference materials for measuring thermal conductivity in the temperature range above 100°C. Therefore, the thermal conductivity of thermal insulation has much deviation that depends on measurement apparatuses and observers in spite of measuring the same specimen. Then, I have researched how far the influence of the difference in measurement methods and apparatuses extends. Furthermore, I have investigated how to measure thermal conductivity in the temperature range above 100°C. In this study, I investigated the measurement apparatuses for thermal conductivity of the identical and same kind of thermal insulations using Guarded Hot Plate (GHP), cyclic heat, and transient hot wire methods in the temperature range from 100 to 1300°C. The thermal conductivities of three kinds of thermal insulations were measured, and compared with each other. As far as measuring the identical and same kind of specimen, it was clear that the results obtained by these three methods agreed with each other within ±10% deviations. Therefore, it is considered that the comparison of the thermal conductivities obtained by the different measurement methods will be practical for improvement of the accuracy measurement at the temperature range in the absence of reference materials.

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