Passive Mitigation of Load Debris in a Magnetically Insulated Transmission Line

The Z driver at Sandia National Laboratories delivers one to two megajoules of electromagnetic energy inside its ~10 cm radius final feed in 100 ns. The high current (~20 MA) at small diameter produces magnetic pressures well above yield strengths for metals. The metal conductors stay in place due to inertia long enough to deliver current to the load. Within milliseconds however, fragments of metal escape the load region at high velocity. Much of the hardware and diagnostics inside the vacuum chamber is protected from this debris by blast shields with small view ports, and fast-closing valves. The water-vacuum insulator requires different protection because the transmission line debris shield should not significantly raise the inductance or perturb the self- magnetically insulated electron flow. This report shows calculations and results from a design intended to protect the insulator assembly.