Initial engineering design and development of HTS magnet systems for all planar coils stellarator at Thea Energy

Thea Energy is revolutionizing stellarators by utilizing innovative arrays of small surface-shaping coils in conjunction with dozens of major toroidal coils, all planar and constructed from high-temperature superconductors (HTS) REBCO conductors. In line with the optimization of stellarator equilibrium, magnetic design and benchmarking of all small shaping coils have been performed and accuracy of <0.1% error has been achieved in Ansys simulations with automation process. The HTS coil design considers the critical current of REBCO as a function of magnetic field and temperature, as well as conductor stabilizer/substrate availability, given the constrained space inside the stellarator system. We are currently engaged in prototype design of single coil and the 3x3 coils panel. Two cryostats are being specially designed for these prototype coil tests at 20 K, including a small direct-conduction-cooled cylindrical cryostat with a pulse tube cryocooler, and a large rectangle cryostat with both cold helium gas and GM cryocoolers. This prototyping campaign aims to validate the design and understand the mutual interactions among the coils, especially during fast-discharge or quenching scenarios.