A low AC loss, fast ramp HTS solenoid prototype for compact Spherical Tokamak

July 25, 2023

The primary goal for this project is to build and test a Bi-2212 HTS insert prototype coil designed by Princeton Plasma Physics Laboratory (PPPL) for the next step compact spherical tokamak (ST) ohmic heating central solenoid in a fusion pilot plant (FPP). The central core of a ST pilot plant is its innovative in-board coil system. For a ST pilot plant, its largest superconducting magnet challenge is the center column where the combined in-board toroidal field (TF) and Ohmic Heating (OH) coils are assembled inside a center stack casing where plasma facing components are attached. A high field, high temperature superconductor (HTS) solenoid coil inside the bore of TF inner leg bundle will decouple the inner TF bundle from the central solenoid to avoid trapping the OH coil outside the inner TF bundle lead flags. Recent evaluations of Bi-2212 wires have shown that Bi-2212 conductors have two orders of magnitude lower AC losses compared to any REBCO conductors, very comparable to ITER Nb3Sn wires. This makes Bi-2212 wires suitable and potentially the only viable high field option for a fast ramp of high field solenoid for compact ST operations. This is significant because most recent studies in support of private fusion companies have shown promising results of net fusion gain by operating a pulsed tokamak machine.

Bruker OST

DUNS / SAM UEI: 078601429000

Yibing Huang, [email protected]

Princeton Plasma Physics Laboratory (PPPL)

Dr. Yuhu Zhai, Dr. Yuhu Zhai