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Since 2011, the Institute for Basic Science has been developing a linear accelerator, called RAON, for a rare isotope science project. The linear accelerator utilizes an electron cyclotron resonance (ECR) ion source for generating intense highly charged ion beams. A superconducting magnet system for a 28-GHz ECR ion source consists of six hexapole coils nested inside four solenoid coils made with low-Tc superconducting wires of NbTi. The superconducting magnets provide an axial magnetic field from four solenoid coils and a radial magnetic field from six hexapole coils to extract an ECR plasma stream that controls the flow current. The electromagnetic force acts on the superconducting magnets due to the magnetic field and flowing current. Therefore, electromagnetic characteristics of the superconducting magnets should be analyzed to minimize the electromagnetic force that causes coil motions and coil strains during excitation. In this paper, the design of superconducting magnets for a 28-GHz ECR ion source is deduced by analyzing the magnetic field to extract intense highly charged ion beams and an electromagnetic force to minimize coil motions and coil strains. The arrangement of the superconducting magnets is inferred by analyzing the magnetic field and the electromagnetic force. Also, the application of an iron pole is considered to improve the stability with a lower operating current. Analysis is conducted by using finite element method simulation.

Quench protection is one of the most important issues for magnet applications using 2 G HTS tapes because of their non-self-protecting properties. Although many researchers have examined the quench/recovery characteristics of HTS magnets to establish the required stability, new information on the quench/recovery characteristics of the recently commercialized HTS magnet with GdBCO CC is needed. In this study, the quench/recovery characteristics of Zr-doped (Gd,Y)BCO CC pancake coils that were insulated with various materials, such as copper and Kapton tapes, were examined in a liquid nitrogen (LN2) bath. The minimum quench energy (MQE) and normal zone propagation (NZP) velocity of the Zr-doped (Gd,Y)BCO CC pancake coils are discussed in terms of the quench/recovery test results.

The electric signals for the voltage as a function of distance between Hall devices and permanent magnets over the radial artery were investigated. The electric sgnals, that means signals of arterial pulse wave, were differentiated by the hardware of circuits and then were changed to differential signals as magnetic field. The 3-D images simulated by the software as function fo the intensity of differential signals were achieved. It shows that these system can apply to pulse diagnostic apparatus of porthble type medical instrument.

We studied the development of spatial pulse diagnostic apparatus with magnetic sensor array using giant magnetoresistance (GMR)/spin valves (SV). Magnetic field distributions for the permanent magnet of 10 arrays using the finite element method (FEM) in a sensing surface were simulated. The characteristics of GMR/SV sensor array consisted of the boundary limit of the sensing magnetic fields and the sensitivity of ΔMR/ΔH below 20 Oe and 1%/Oe, respectively.

This paper presents quench test results, of both experiment and simulation, of a racetrack pancake coil wound with a GdBCO-coated conductor tape in a solid nitrogen (SN2) cooling system at 58 K. The longitudinal normal zone propagation velocities in the curved section were 2 times faster than those in the straight section. Therefore, the straight section should be protected more than the curved section when using racetrack-type, GdBCO pancake coils in large-scale rotating machines. The simulated results showed good agreement with the experimentally observed normal zone initiation times.