LPI Risk Estimates for the 4-MJ Vulcan Laser Facility

A proposed 4-MJ two-sided KrF laser facility is being planned by Xcimer Energy Corporation to obtain engineering break-even with fusion gain exceeding 50 [1]. The point design uses a "hybrid" drive for the implosion to mitigate laser imprint, whereby an initial laser pulse creates x-rays from a hohlraum to create a plasma atmosphere around the fusion capsule and set the implosion adiabat, and subsequent laser pulses directly drive the implosion. Initial assessment of laser-plasma instability (LPI) risks for this design, using steady-state linear theory, indicates low to moderate risk for backscatter, and potentially higher risks for side scatter. We will present estimated laser-plasma conditions from 1D and 2D radiation hydrodynamics simulations, and discuss the calculated LPI gains and thresholds.