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In the project for the International Thermonuclear Experimental Reactor (ITER), a Central Solenoid (CS) model coil was developed to demonstrate the feasibility of the coil design and fabrication procedure. The model coil was installed in the test facility at JAERI, Naka, and a performance test is being carried out. The cool-down was completed without cold He leakage at the beginning of April 2000. We could charge the model coil up to the nominal current of 46kA without quenching in the first DC charging test. The model coil could generate the maximum field of 13T, and the stored energy was 640MJ. A manual dump test was also performed with the time constant of 5.3s from the nominal current. A maximum voltage of 4.8kV appeared in the coil during the dump test, and no damage was found after the test. In the pulse operation test, the coil could be ramped up to the nominal current in 26s, with the maximum ramping rate of 0.5T/s. The target ramping rate of 0.4T/s was satisfied. The test results are described in this paper.

A model coil of a superconducting magnetic energy storage (SMES) device, which is a forced-cooled Nb-Ti coil, has been fabricated and a performance test at cryogenic temperatures has been carried out. The SMES model coil is composed of 4 dual pancakes and its total weight is 4.5t. The applied conductors are cable-in-conduit conductors cooled by supercritical helium (SHe) at 4.5K and 0.7MPa. SHe is supplied to the SMES model coil and the structure by a reciprocating bellows pump. The test facility is located at the International Thermonuclear Experimental Reactor (ITER) common test facility, was constructed for the testing of an ITER central solenoid model coil. In the experiments, cool-down was finished within 10 days under controlled temperature differences in the SMES model coil. During cool-down and 4.5K operation, pressure drop characteristics of the conductor were measured and the friction factor estimated. The pressure drop characteristics of the SMES model coil were in good agreement with those of the previous cable-in-conduit conductor. During static operation without current, the heat load and refrigerator operation conditions were measured. The heat load of the SMES model coil is 7.5W, which is within the expected value.

JAERI has developed 50kA current leads for the International Thermonuclear Experimental Reactor (ITER). The Center Solenoid (CS) Model Coil program is under way by means of international collaboration in ITER-EDA. The CS model coil is being developed for ITER CS coil and is for demonstration for ITER construction. The performance test of the CS model coil will be carried out at the JAERI ITER common test facility (CTF). The current lead consists of the vertical lead and the connection lead. The vertical lead is a vapor-cooled type and has a cable-in-conduit geometry. The vertical lead was designed with a heat leak of 1.2W/kA at a helium flow rate of 0.06g/(s·kA). The measured heat leak satisfied the designed value. The connection lead was made from copper pipe soldered with NbTi supreconducting wires. The pipe was stabilized by the supreconducting wires and a cooling channel. The current lead was operated up to 60kA. The design and the performance test results of 50kA current leads are reported. The results meet the specifications for the CS model coil test and for the ITER real machine.

The DPC-TJ coil experiment took place successfully at the Japan Atomic Energy Research Institute (JAERI) in 1991. This coil was developed by Toshiba and JAERI in collaboration to demonstrate the realizability of superconducting coils for fusion with high average current density of 40A/mm2. The DPC-TJ was charged up to its rated current of 24kA (40A/mm2) at 7.6T without quench in the DPC test facility. Thereafter the electromagnetic performances were tested by measuring Ic and Tcs, and the critical current at 12T was estimated 41kA. Many electromagnetic results were obtained, which are necessary for the design of the next fusion machines like International Thermonuclear Experimental Reactor (ITER).