Magnetic insulation in triplate vacuum transmission lines

Magnetically insulated vacuum feeds have been investigated for use in an electron beam fusion accelerator. The magnetically insulated transmission lines would transfer the power pulses from many accelerator modules to a single diode region or multiple diodes to generate currents of the order of 100 MA. This approach may allow the present limits on power flow through dielectric/vacuum interfaces to be overcome. Experiments are reported on vacuum triplate transmission lines with a 24 ohm wave impedance and peak applied fields up to 1 MV/cm. Both ohmic and field emission loads were used with the center conductor pulsed positive. Measurements were made with a transmission line with a pulse double transit time length longer than the pulse risetime. Diagnostics included total current and boundary current, input and output voltages, and diode calorimetry. Accurate measurements of current, voltage, power, and energy transfer, as a function of several loads are reported and a comparison is made with theoretical models.