High gain fusion in a Staged Z-pinch

摘要

The implosion of a Staged Z-pinch is simulated for parameters that are characteristic of the ZR accelerator, at Sandia National Laboratories. The Staged Z-pinch configuration is comprised of a cylindrical, Silver (Ag) plasma shell, 3-mm outer radius, 0.01-cm thick, imploding onto a uniform-mixture fill (target) of Deuterium-Tritium (DT); the Z-R parameters are: 130 ns, 27 MA, 22 MJ; and the simulation code is MACH2, a 2–1/2 D, radiation-MHD code. During implosion magnetosonic shock waves are generated which propagate radially inward at different speeds in the liner and target plasmas, producing a shock front at the interface between the liner and target plasmas, and a conduction channel ahead of the liner that facilitates target preheating. The Ag/DT interface remains stable throughout the compression, even as the outer surface of the liner becomes RT unstable. At peak compression a string of hot spots forms in the target plasma, that triggers ignition and a fusion-energy yield in excess of 200 MJ; net-energy gain approaching a factor of 10, based on the total stored energy.