Axisymmetric Magnetic Mirror Applications – Divertor Test Stand to Fusion Power Plant

Abstract

Axisymmetric mirrors can be MHD-stabilized by end losses. Neutral-beam-sustained operation to β~0.6, and T_e~0.2 keV, with 5 ms 5 MW neutral beams on the Gas Dynamic Trap (GDT) has been demonstrated at the Budker Institute in Novosibirsk, Russia. Applications of this concept can reduce risks in the fusion program. A GDT-scale facility could test plasma-material interactions (PMI) at up to 400 MW/m² and 5 s pulse duration for divertor development. Extrapolation of the GDT to a Dynamic Trap Neutron Source, DTNS, provides a DT-fusion neutron flux of 2 MW/m² over 1 m², at a power-plant efficiency of Q ~ 0.07. (A DTNS enables development and testing of materials and sub-component structures, for fusion power plants, MFE or IFE. A DTNS functions regardless of whether the tested components work. These developments would reduce risks for a tokamak Fusion Nuclear Science Facility (FNSF)). Further extrapolation to 0.2 ≤ Q ≤ 10 single-cell or tandem mirror yields several fusion-fission hybrid applications. Further extension to a pure-fusion axisymmetric-tandem-mirror power plant, requires Q>10. Tandem mirrors demand the use of different stabilization techniques that are not dependent on out-flowing plasma, a number of which have been proposed, and could be experimentally tested on the GDT.