Improving current coupling to the load in magnetized liner inertial fusion*

Magnetized Liner Inertial Fusion (MagLIF) is a magneto-inertial fusion scheme under investigation on the Z facility. In MagLIF, an axial magnetic field is applied to a metal cylinder containing gaseous fusion fuel, a multi-kJ, few-ns-duration laser is used to heat the magnetized fuel, and then the Z-Machine current flows through the metal cylinder, causing it to implode. Simulations of the MagLIF concept predict that 100 kJ DT yields are possible with 25-30 T, 4-6 kJ laser energy deposited, and 22-24 MA. In initial experiments the input parameters were only 10 T, 0.3-0.7 kJ, and 16-18 MA peak load current, resulting in 0.2-0.4 kJ DT-equivalent yield. Focused efforts to improve all three parameters are underway. A significant improvement in peak load current was demonstrated with a new final transmission line and return can design, which reduced the inductance while simultaneously increasing the anode-cathode gap. A peak load current of approximately 20 MA has been measured, and 22+ MA appears feasible with further improvements to the design.