Numerical Simulation of a No-Insulation BSCCO Toroidal Magnet Applied in Magnetic Confinement Fusion

Abstract

At present, the Tokamak has become a mainstream form of the magnetic confinement fusion device. The toroidal field (TF) magnet in the Tokamak system is required to generate a high-steady field to confine and shape the high temperature plasma. To secure high current density and high thermal stability, the no-insulation (NI) winding technique is used in the fabrication of the TF magnet. During plasma operation, heat is generated in the TF magnet caused by the interaction with central solenoid (CS) coils, poloidal field (PF) coils, and the plasma current. The heat generated in NI coils is complex owing to the existence of current flow between adjacent turns. Thus, it is necessary to calculate the thermal problems. Taking into consideration the effect of turn-to-turn contact resistance, this paper presents the thermal behavior of a NI toroidal magnet under different operating conditions. The NI toroidal magnet is composed of 10 double-pancake (DP) coils wound with BSCCO tapes. The analysis procedure combines the finite element method (FEM) with an equivalent circuit model. This analysis has applicability and practical directive to the design of cryogenic cooling system for NI toroidal magnet.

The Relationship between Symbolic Agricultural Products and Agricultural Economic Development Based on Numerical Analysis

“…e methods of this research include literature research, information research, and empirical analysis, as shown in Figure 2 [15].…”

Study of contact resistivity of a no-insulation superconducting coil

“…In previous studies [18][19][20], the NI coil's detailed distributed circuit model consists of N t turns, and each turn is divided into Div elements, as shown in figure 1. The total number of elements in the coil is N, which equals N t × Div.…”

“…In order to calculate the magnetic field produced by the coil, the ECG model is coupled to a commercial finite element method (FEM) software, COMSOL Multiphysics, and uses external Matlab subroutines for the current distribution. In [19] the authors built a FEM-circuit model in Ansys to remove the needs of external Matlab codes, and each element per turn of the coil in the FEM model is coupled to the inductors in the circuit model built in the same software. Then, the inductances in the circuit were calculated through the FEM model.…”

Design, construction, and testing of no-insulation small subscale solenoids for compact tokamaks

“…The no-insulation (NI) coil concept has been actively investigated since it was introduced over a decade ago. NI HTS coils have been successfully tested in the high field magnet community for various non-fusion applications [18][19][20][21]. The slow current charging time [18][19][20], however, is a potential issue when the NI coil design concept is applied for operating large scale fusion magnets, particularly for the central solenoid where a fast current ramping is needed for plasma startups [22,23].…”

“…NI HTS coils have been successfully tested in the high field magnet community for various non-fusion applications [18][19][20][21]. The slow current charging time [18][19][20], however, is a potential issue when the NI coil design concept is applied for operating large scale fusion magnets, particularly for the central solenoid where a fast current ramping is needed for plasma startups [22,23]. Stellarators and other fusion devices such as a field-reverse configuration (FRC) device, however, do not need a fast ramping field to startup plasma and the NI coils can be promising.…”