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The various effects of temperature on the Ginzburg-Landau parameter, thermodynamic and upper critical field of the [Nb.sub.3]Sn strands are being discussed. The results show that the surface barrier is responsible for the asymmetry shown in the magnetic relaxation rate for flux entry and exit.

The Heating surge and temperature oscillation is analyzed in the poloidal field (PF) and toroidal field (TF) coils of Korean Superconducting Tokamak Advanced Research (KSTAR). The experimental results show that the maximum temperatures in TF and PF are about 5.7 K and 5.9 K respectively.

The Korean Superconducting Tokamak Advanced Research (KSTAR) device is a tokamak with a fully superconducting magnet system, which enables an advanced quasisteady-state operation. The effect of three-dimensional heat conduction and the eddy current loss in the vacuum chamber of KSTAR is described.

The relationship between the current density and magnetic flux density is studied by using Turner's target field approach for spherical conductors. The results show that by using this method, uniform or gradient magnetic field that vary linearly along the x or y direction can be generated.

Properties of ferromagnetic materials are measured at liquid nitrogen temperature.

The effects of transformer geometry on magnetic field leakage are examined and reported.

Research involving simulations of dynamic stress in PF (Polodial Field) superconducting magnets for the KSTAR ( Korea Superconducting Tokamak Advanced Reactor) is described and discussed.

A relation between travel of the bending roller and spring back radius is described. The relation was obtained by means of virtual manufacturing with a 3-roll bending process.

MFEM1D, a numerical method based on the finite-element method, is described. It is used to investigate the helium expansion and quench propagation in cable-in-conduit conductors (CICC).

Effects of inlet pressure and mass flow rate on the temperature margin and heat-removal characteristics of the Samsung Superconducting Test Facility (SSTF) are examined and discussed.

Thermal analysis of the Korea Superconducting Tokamak Advanced Research (KSTAR) device's poloidal field (PF) was accomplished using the code SAITOKPF

The development of conductors with an aluminum super-stabilizer was proposed for some applications of accelerator detector magnets for high-energy physics and superconducting magnet storage energy devices. The conductors are designed with the cryogenics stabilization by using a large amount of low resistance aluminum stabilizer. However, it has induced to some new problems. One of these is the effect of the current redistribution between superconducting strands and stabilizer on the quench propagation and stability. In this study, we assume a superconducting magnet to be immersed in liquid helium. A quasi-three-dimensional model is proposed to study thermal diffusion in superconducting magnet and current diffusion is based on the solution of Maxwell's equation. The uniform temperature distribution in the cross-sectional area of conductor is taken into account due to the high thermal conduction of stabilizer and small size compared with the length. An adaptive mesh scheme COLSYS is employed to capture the solution of temperature and current in the front of normal position. The computational model includes nonlinear thermal and electrical characteristics in superconducting strands and aluminum stabilizer and heat transfer of helium. The influence of current re-distribution between stabilizer and superconducting strands on the quench is studied. Index Terms--Adaptive mesh, current diffusion, normal zone of finite length propagation, quasi-three-dimensional numerical model, quench, stability, superconducting magnet.

The background magnet system on the Samsung Superconductor Test Facility for Korea Superconducting Tokamak Advanced Research is discussed.

Research describing the quench characteristics of a superconducting magnet consisting of several pancake shaped coils is presented. The application of the moving mesh finite volume method to a simulated quasi-three-dimensional model for quench processes is investigated.

Research is presented describing the design of a 50 kA superconducting transformer that charges a cable-in-conduit conductor (CICC) short sample for one sescond. The transformer is part of the Samsung Superconductor Test Facility, that is being designed for Korea Superconducting Tokamak Advanced Research.

The stability margin of NB3Sn cable-in-conduit-conductor was assessed using a numerical model, based on the finite volume technique.

The transition temperature T(sub c), the thermodynamic critical field B(sub c), and the upper critical fields B(sub c2) of Nb(sub 3)Sn were numerically calculated by Eliashberg theory of strongly coupled superconductors using the Einstein spectrum. It was found that the impurity concentration was relatively low and the strain effects were due to the phonon mode softening both at high and low frequencies.

As a part of a conceptual design study for a steady-state demonstration reactor (K-DEMO) of which the major and minor radii are around 6.5 and 2.0 m, respectively, toroidal field magnets which can generate around 8 T at plasma center with a peak magnetic field of \sim16 T are being studied. For conductor tests under such a high magnetic field, a new conductor test facility is required and a conceptual design activity is going on, in parallel. The conductor test facility, named SUCCEX (SUperConducting Conductor EXperiment), will feed the sample with a current up to 100 kA and the sample temperature will be varied from 4.5 K to \sim20 K. Moreover, Sultan-like conductor tests, U-shaped joint-less sample tests will be conducted. The 16-T \Nb3 \Sn magnet, with a bore of \sim1-m diameter, is divided into three concentric split pairs, inner coil (IC, peak field of 16.4 T), middle coil (MC, 13.6 T), and outer coil (OC, 7.9 T), connected in a series, with a nominal operating current of \sim18 kA. Each split pair coil is made of its own distinctive rectangular shaped cable-in-conduit conductor (CICC). The overall design concept and preliminary results of electro-magnetic, structural, and thermo-hydraulic analysis are presented. [ABSTRACT FROM PUBLISHER]

Two identical conductor samples were fabricated from 110 m length cable prepared for qualification of the manufacturing process for Phase II procurement of ITER TF conductor. Superconducting strand characteristics, cabling specifications, and the stainless steel jacket sections are described. Sample assembly and instrumentation of various voltage taps and temperature sensors have been prepared according to specified procedures for conductor performance qualification. The performance test program which was agreed to by the SULTAN working group was applied to the conductor samples. To assess the current sharing temperature (Tcs), standard analysis procedures were adopted. The Tcs of both samples at 68 kA with a background field of 10.78 T after a 1000 cyclic load are well above the acceptance criteria. Behavior of individual “star” voltage taps which are located at different positions and which are possible origins of rather large discrepancies in the Tcs of identical samples is discussed. The effective strain and the transition index of the samples are obtained from the experimental data. [ABSTRACT FROM PUBLISHER]

While the manufacturing of superconducting CICC (cable in conduit conductor) and winding conductors into winding packs for ITER TF magnets, cold work is unavoidably applied on the jacketing tube. This article investigates the effect of plastic deformation on low temperature mechanical and magnetic properties of austenite 316LN stainless steel tube for ITER TF conductor. To simulate the manufacturing process of TF magnet, tubes were compacted, extended to 2.5% in longitudinal direction and heat treated. After each step, specimens were sectioned using wire cutting EDM, and tensile tests at 4 K, magnetic susceptibility measurements, and hardness tests have been carried out on those specimens. Remarkable reductions of elongation at failure have been observed as the amount of cold work is increased through compaction and extension. Further, correlations among results of tensile tests, magnetic susceptibility measurements and hardness tests are presented. [ABSTRACT FROM PUBLISHER]