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A two-turn D-shaped test coil with a height of 2.0 m and a width of 1.8 m is fabricated by a react-and-wind method by using a 20 kA Nb3Al cable-in-conduit (CIC) conductor. The total strain of the D-shaped test coil is about 0.57 percent, the same as the triplex-CIC sample fabricated by a W&R method, indicating that bending did not influence the I(sub c).

Tests of the International Thermonuclear Experimental Reactor (ITER) Toroidal Field (TF) Insert and Central Solenoid Model Coil (CSMC) are evaluated.

Performance of the NbAl Insert and the International Thermonuclear Experimental Reactor (ITER) Central Solenoid Model Coil (CSMC) are discussed.

Test results of the 460-kA Nb3Sn conductor joint for the ITER model coils are presented.

Japan Atomic Energy Research Institute is constructing the International Thermonuclear Experimental Reactor common test facility for the Central Solenoid Model Coil which is around 180 tons, a forced-flow cooled magnet with the maximum pulsed operation of 2 T/s and generates the rated magnetic field of 13 T at 48 kA with stored energy of 668 MJ. The test facility consists of a coil vacuum chamber, a cryogenic system with the 5-kW refrigerator and 500-g/s cryogenic pump, two pairs of 50-kA current leads, two DC power supplies (50kA and 60kA) and two JT-60 pulsed power supplies (50 kA, [+ or -]4.5 kV and [+ or -]40 kA, [+ or -]1.5 kV). The facility will be demonstrating the refrigeration and operation of a fusion pulsed magnet and the design and construction will accumulate experience towards the construction of ITER.

A 40-kA [Nb.sub.3]Al cable-in-conduit conductor has been developed for the toroidal field coils of fusion reactors, because [Nb.sub.3]Al has excellent mechanical performance. This conductor consists of 405 copper-stabilized multifilamentary strands inserted into a CuNi circular conduit. The [Nb.sub.3]Al strands are fabricated by the Jelly-roll process with a diameter of 1.22 mm. This conductor could be operated up to a current of 46 kA at an external field of 11.2 T. Accordingly, [Nb.sub.3]Al promises to soon become a useful superconductor for large-scale high-field applications, such as fusion machines.

The effect of cyclic pulsed operation on the coil performance was studied from the electrical and mechanical points of view in the second experiment of the [Nb.sub.3]Sn Demo Poloidal Coil (DPC-EX). Current sharing temperatures, ac losses, displacements, and strains were measured before and after cyclic pulsed operation, which consisted of about 350 cycles. No degradation of the electrical and mechanical performance of the DPC-EX was observed in the range of these cycles.

In March 1993, the highest magnetic field of 21.1 T was generated in a 50 mm diameter clear bore. It was accomplished by using a 20 T superconducting magnet with a large bore developed at the National Research Institute for Metals. In order to obtain higher fields over larger spaces, three Wind & React coils having identical winding parameters were fabricated as the innermost coils. By removing a stainless steel bobbin from the second coil, improvement of training behavior as well as enlargement of a clear bore diameter could be achieved. A bobbin was also removed from the third coil. It was wound with a newly developed conductor and recorded the field of 21.1 T.

Multilayere wire wound coils for pulsed magnets with long pulse duration were manufactured using a newly developed Cu-Ag microcomposite wire which has excellent properties of high conductivity, high mechanical strength and high homogeneity along the wire. Test results of magnets with various bore diameters both with and without internal reinforcements proved the usefulness of this new wire. One of the magnets wound with inter layer reinforcements generated a magnetic field of 68.0 T with 1.9 ms rising and 3 ms decay time in the space of 12.2 mm inner winding diameter.

Japan Atomic Energy Research Institute (JAERI) has been developing 13-T, 40-kA conductors for the ITER Central Solenoid Scalable Model Coil. The conductors are composed of high performance [(NbTi).sub.3]Sn strands and titanium conduit. In this development work, 15-km length strand fabrication from a 100-kg billet, chrome plating, cabling of 675 or 768 strands, jacketing of titanium conduit, and so on were conducted by two mass production lines. In this paper, several test results are reported such as critical current measurements of full-scale conductors and AC loss measurements of sub-scale conductors.

The Toroidal Model Pancake is a test coil that was constructed by the Japan Atomic Energy Research Institute for fusion reactor studies. Built of a 90-m hollow cooling monolithic conductors, it has an 1-m bore and a 1.5-m outer diameter. It was subjected to ac loss measurements which found the effective diameter of its (NbTi)3Sn and niobium titanium conductors to be 4 micrometer and 39 micrometer, respectively.

The characterization of the Toroidal Model Pancake (TMP) is presented. The TMP is a superconducting coil constructed by the Japan Atomic Energy Research Institute for fusion reactor studies. Built of hollow cooling monolithic superconductors, it begun testing in Aug 1992. Its performance is described along with cooldown, pressure drop, stability and mechanical issues.