Updates to the Laser Gate Experiment for Increasing Preheat Energy Coupling Efficiency in Magnetized Liner Inertial Fusion (MagLIF)
Stephanie Miller, University of Michigan
Magnetized Liner Inertial Fusion (MagLIF) is a critical concept for the study of fusion sciences and stockpile stewardship being tested on the Z Machine at Sandia National Laboratories (SNL). MagLIF target designs feature a laser entrance hole covered by a thin (few-micron-thick) window to hold the pressurized fusion fuel in place. There are energy losses as a preheating laser beam ablates through this plastic window. Laser-window interactions reduce heating efficiency and mix window and target materials into the fuel. To reduce these losses and improve fusion yield, we are implementing a system that removes this window before the laser beam passes through its opening. This window removal method is referred to as a Laser Gate.
We have demonstrated a Laser Gate proof of concept at the University of Michigan (UM) and preliminarily scaled targets to SNL MagLIF parameters. We are increasing the diagnostic capabilities of our UM setup to include interferometry to measure the density of the gas/fuel as it escapes from the target. Additionally, these experiments will be conducted in vacuum to better replicate the MagLIF target environment. This UM test stand will allow us to further study window-opening dynamics, assess system jitter, and determine specifications for a pulsed current device to be built for an upcoming shot series at SNL. We will report on the results of these intermediate experiments as well as our designs for transitioning this study to the already established preheat platform at Sandia National Laboratories.
Abstract Author(s): S.M. Miller, S.R. Klein, A.P. Shah, B.J. Sporer, C.C. Kuranz, N.M. Jordan, R.D. McBride