Fusion plasmas contain a huge amount of thermal and magnetic energy which can be dumped in a flash during a sudden termination event, called a disruption. One scientifically interesting but unfortunate consequence is the formation of a high-current beam of relativistic “runaway” electrons, which can cause significant melting of plasma-facing components. Of course, we would like to avoid disruptions and runaways altogether, but we must also be prepared to mitigate their deleterious effects.
We can measure these energetic electrons in time, space, and energy to understand their generation and assess the best mitigation strategies. In SPARC, we will detect runaways via their hard x-ray bremsstrahlung as well as visible synchrotron light. We will test the first-ever implementation of a Runaway Electron Mitigation coil, and evaluate any damage to first-wall materials.
– We model how relativistic electrons are accelerated in fusion plasmas including novel generation mechanisms due to the nuclear environment
– We simulate how runaway electrons emit photons and characterize detector prototypes with gamma, neutron, and ion sources
– We are engineering a novel Runaway Electron Mitigation Coil to prevent runaway beam formation
– We evaluate how high-energy electrons impact – and likely melt – fusion-relevant materials
Commonwealth Fusion Systems; Columbia University; Fiat Lux; Chalmers University and KTH Stockholm, Sweden
This work supported in part by Commonwealth Fusion Systems.
