Faster Fusion Power from Spherical Tokamaks with High-Temperature Superconductors

Abstract

The use of spherical tokamaks and high-temperature superconductors (HTSs) offers the possibility of achieving faster fusion power by allowing plants of high-field, high plasma pressure, and good energy confinement thereby reducing the need for large plasma volumes. This spatially efficient energy-dense approach accesses quicker development and the possibility of modular construction. An overview of high-performance computational (HPC) capabilities at Tokamak Energy is given. We describe, at a highlevel and in practical terms, the use of theory, models, algorithms, and applications to develop spherical tokamak designs in an integrated fashion. A challenge of spherical tokamaks is that there is less room for the neutron and gamma shield necessary to prevent heating and radiation damage to the HTS core. Tungsten boride shield materials may be able to provide an optimal combination of inelastic (n, gamma) reactions and gamma attenuation. The neutron energy is reduced largely by inelastic reactions to energies where boron absorption occurs, while tungsten attenuates the resulting gammas rapidly. Although inelastic scattering is shown to be the key to tungsten boride shield performance, it is shown that the remaining neutrons generated in the plasma and transmitted without reaction through the shield dominate the heat deposition in the HTS core.