Radiation Environment and Damage of HTS Magnets in an ARC-Like Reactor

Compact fusion reactors require high temperature superconductors (HTS) for the production of high field magnets capable of confining the plasma and achieving enough fusion power to reach commercial interest. The generation of high energy neutrons in the plasma, together with the consequent proliferation of secondary particles, threatens the long term performance of the HTS materials due to the heat load and radiation damage. For this reason it is crucial to develop tools for the comprehensive simulation of radiation environment and effects throughout the reactor structure. Here we present Monte Carlo simulations of an ARC-like reactor yielding the neutron and secondary particles spectra, the power deposition, and the materials damage mapped over the whole system, focusing on the effects on the toroidal field and poloidal field HTS coils. We find that the peak of the heat deposition in the magnets is located near the divertor, and that a strongly non-homogeneous distribution of damage urges the geometrical optimization of neutron shields.