Advances in magnet and shielding designs for fusion and high energy physics applications

Abstract

This paper introduces the work scope of a collaboration among EUROfusion, CERN, and F4E to create models and design tools applicable both for fusion devices and muon accelerator magnets. The study described here is motivated by the commonality in challenges to design magnets and radiation shields applicable to compact fusion machines to serve as neutron source, and future high-energy physics experiments such as the muon collider or high intensity neutrino factories.

Both applications present design challenges revolving around the trade-off between the need for very high fields over a relatively large free bore, while keeping the coils sufficiently far away and properly shielded from radiation to limit heat load and damage to materials. The present focus is on creating design models and tools for superconducting solenoids built exclusively with high-temperature superconductors (HTS), or in a hybrid configuration with low-temperature superconductors (LTS).

We use the pinch solenoid magnets for a mirror fusion machine as a case study. The magnetic field requirements and configuration, material limits, structural constraints, and shielding properties are considered while using an optimization model to scan and systematically size the coil/shield combination. The investigation involves conductor selection, mechanical analyses, and cooling schemes. Moreover, we examine the optimization of magnet stability in operation, surveying radiation-shielding materials and innovative shielding concepts. The similarities in design challenges between fusion devices and accelerator magnets are highlighted.