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At the Wakasa Wan Energy Research Center (WERC), an accelerator system with a 5 MV tandem accelerator and a 200 MeV proton synchrotron is used for ion beam analyses and irradiation experiments. The study of cancer therapy with a proton beam is also performed. Therefore, the stable operation and efficient sharing of beam time of the system are required, based on the treatment standard. Recent developments and the operation status of the system put stress on the tandem accelerator operation, magnifying the problems.

We developed rectangular-shaped Bi-2212 conductors. At 4.2 K and 30 T, the 37- and 349-filament conductors exhibited J C values of 151 and 125 kA/cm 2 , respectively. Moreover, we measured the distribution of I C for a 25 m-class 349-filament conductor. The end-to-end I C value was 66 A at 63 K, self-field, and the variation in I C was about ±10%. We also fabricated a test coil with 50 m-class, 349-filament conductor. The test coil carried 510 A (using a criterion of 10 −13 Ω m) and generated B 0 =0.95 T at 4.2 K without backup field, resulting in a current density in the test coil of 150 A/mm 2 . The coil performance was almost 80% that of a short sample with a magnetic field applied perpendicular to the tape surface.

An 80 meter long Rutherford cable was fabricated with 20 strands of 0.8 mm diameter Bi-2212 wire. The conductor utilized in this cable was a double stack design (7 × 61) comprising 427 filaments. The critical current (Ic) of the cable was measured at liquid helium in applied magnetic field up to 4T. The Ic results of the cable show no degradation when normalized to the strand. The cable was sectioned into four 17-meter lengths and one 10-meter piece. These sections were heat treated and the ends cut and tested. The average Ic of all cable pieces tested was 2990 A ± 10% in self field. The bending strain of Rutherford cables with a ceramic coated Ni-alloy core showed little or no degradation up to 6%. In contrast, cables manufactured without a Ni-alloy core showed critical bending strains of about 2%.

We developed a new strong Rutherford cable using Bi 2 Sr 2 CaCu 2 O y (Bi-2212) high temperature superconducting (HTS) wire, which consisted of 427 superconducting filaments and AgMgSb alloy outer sheath. This wire exhibited excellent critical current (I c ) and critical current density (J c ) values at 4.2 K in self-field (285 A and 340000 A/cm 2 , respectively) and a room temperature tensile strength of 180 MPa. The Rutherford cable was prepared with a NiCr alloy strip as a cable core. The degradation of full cable I c induced by Ni diffusion was reduced by introducing a ceramic barrier layer between the Bi-2212 superconducting wires and the NiCr cable core. A full cable I c value of 3500 A at 4.2 K in self-field was obtained in short sample fabricated by using a cable core with a ZrO 2 film barrier layer. Finally, we fabricated an 80-m-long Rutherford cable by using a cable core with a MgO tape as a barrier layer and evaluated its full cable I c . I c values of 17-m-long sections cut from a continuous 80-m-long cable were greater than 2700 A at 4.2 K in self-field.

We report on the effects of field-induced Γ–X resonances on carrier transport and optical properties of GaAs/AlAs type-I short-period superlattices (SLs). We have observed an anomalously delayed photocurrent and Γ2-hh1 photoluminescence originating from X1–Γ2 mixing. These observations clearly suggest that electrical conductivity and optical properties even in type-I SLs are seriously affected by X states in the applied electric field.

An energy supply system for initial manned lunar bases was studied. A 300 kWe plant was considered combining a liquid metal fast reactor with a potassium Rankine cycle. The reactor vessel is buried under ground and a regolith layer works as shielding. The settling and starting procedures on the Moon are also discussed.

This paper concerns the development of a digital PCM current differential relay for transmission line. The developed relay has an automatic synchronization function and its interface to digital multiplex equipment is designed according to CCITT recommendation G.703 co-directional interface. And also to improve the communication reliability, this relay can be connected to duplicate communication channels with automatic changeover from main to stand-by channel in case of failure of main channel. Detection of communication channel failure is fulled up by built-in CRC (cyclic redundancy check), fixed bit check, frame synchronism check and, etc. Two 16 bits microprocessors, one is for current differential calculations and another is for data transmission functions, can construct the full relay function. The relay has been tested by digital simulated fault currents which were calculated by EMTP (Electro-magnetic transient program) for a large capacitive cable line.