Laser gate experiment for magnetized liner inertial fusion (maglif) utilizing a mini-pulser*

In Magnetized Liner Inertial Fusion (MagLIF), a laser preheats pressurized fuel inside of a cylindrical metal tube (or “liner”). A preheating laser pulse must ablate a thin laser entrance window (LEW) to deposit energy into the fuel. Energy losses are thought to occur at the LEW from laser plasma interactions (LPI). To reduce energy losses, the LEW could be removed before the laser pulse reaches the LEW. This removal concept is referred to as “Laser Gate.”¹ One proposed implementation of Laser Gate, is to break the LEW by driving an electrical current through a thin wire wrapped around the perimeter of the LEW.¹ The current heats the wire and the LEW perimeter melts. As the LEW breaks, the fuel pressure pushes the LEW away from the contained fuel and out of the laser path. This should reduce fuel-window mixing and LPI in MagLIF. For our initial experiments, we imaged the LEW opening up and away from the laser path. We will report on LEW opening times and our experimental tests of Laser Gate.

[1] S.A. Slutz, et al., Phys. Plasmas 24, 012704 (2017).