Yuquan Chen

Design of the ITER TF Magnet Feeder Systems

The International Thermonuclear Experimental Reactor (ITER) superconducting magnet system requires current supplies from 10 kA to 68 kA. The components relating the electrical power and cryogens through the warm-cold barrier to the ITER magnets are the so-called feeders. In total there are 31 such feeders for the ITER magnet system, 9 of them necessary for the toroidal field magnet system are called TF feeders. Each feeder consists of three main units: the In-Cryostat Feeder (ICF), the Cryostat Feed-Through (CFT) and the S-Bend Box (SBB)/Coil Terminal Box (CTB) assembly. This paper presents the latest design of the TF feeder components.

Development of the Coil Terminal Boxes for the ITER Magnet Feeder Systems

The nuclear radiation levels, magnetic fields and general access restrictions in the ITER Tokamak are such that it is undesirable to place remote control helium supply valves close to the coils. The Coil Terminal Boxes (CTB), which are further away from the coils, are therefore designed for easy access and contain as much as possible the components needing maintenance, such as the cryo-valves. The CTBs also house the electrical cold-warm transitions with the HTS current leads and the NbTi feeder busbars. Also most of the feeder instrumentation is located in the CTB. Based on the functional specification by ITER, ASIPP has manufactured and tested a prototype CTB for the ITER magnet system. This test allowed for the verification of the mechanical design of the cryostat and the thermal shield design. Following a discussion of the ITER CTB design, with particular emphasis on the concepts of flow distribution for the large ITER magnet system, considering safety and maintenance, this paper will also present the results of the prototype CTB development.

Key Components of the ITER Magnet Feeders

Now that ITER is entering construction, many of its systems are in the final stages of design and analysis. Among them the 31 feeders, which will be supplied in-kind by the Chinese ITER partner. The feeders supply the electrical power and cryogens through the warm-cold barrier to the ITER superconducting magnet systems. They are complex systems with their independent cryostats and thermal shields, densely packed with many components, such as the current feeds, the cryogenic valves and High-Voltage (HV) instrumentation hardware. Some of the feeder components are particularly critical and have been designed with great care. Among them the High-Temperature Superconductor (HTS) current leads, designed for unprecedented currents, the 30 kV class, Paschen-hard HV insulation and the bus bar support system, designed to react the multi-ton Lorentz-forces from the bus bars at minimal heat load. This paper discusses the design challenges for these (and other) key components of the ITER magnet feeders.

The Fast-Pulsed Superconducting Dipole Prototype Magnet of HIAF at IMP

The High-Intensity Heavy-Ion Accelerator Facility is a new major engineering project in the Institute of Modern Physics. The dipole magnets of the booster ring are conceived as fast-cycled superconducting magnets with a high magnetic field and a large gap, the warm iron and superconducting coil structure (superferric) is adopted. The coil is wound with a Nuclotron-type superconducting cable to reduce the ac loss. The magnet with a large operation current and a low inductance assures the fast-pulsed operation. Based on the superconducting cable with large operation current, the design of a superconducting coil prototype is shown in this paper. The magnetic field analysis based on 3-D-OPERA is carried out to obtain the basic dimension of coils. Then, the design of the Nuclotron-type superconducting cable, the coil, and coil case are described in detail. In addition, fabrication of the superconducting cable, the coil winding, and other components are also introduced in this paper.

A Compact Superconducting Solenoid for China-ADS Injector II

A compact solenoid for the China Accelerator Driven Subcritical System (China-ADS) injector II has been developed. It includes a focusing solenoid and two steering dipoles. The magnet is compact with an entire length of 160 mm, including the helium vessel and the side flanges. Nonlinear optimization method was used to meet the requirement of focusing strength and stray field with minimized solenoid volume. The steering dipoles are placed inside the solenoid to reduce the magnet size. The structural analysis, quench protection design, and fabrication and test results are presented in this paper.