This report evaluates the pulsed breakdown performance of $C_4{F}_{7}N$ under a 6.8 kV/ns voltage excitation. The pulsed dielectric strength of $C_4{F}_{7}N$ is compared to $S{F}_6$ in the same experimental setup, and it is found that $C_4{F}_{7}N$ concentrations of 50% or greater are required to achieve a dielectric strength greater than or equal to $S{F}_6$. Pure $C_4{F}_{7}N$ demonstrated higher electric field hold-off for longer time periods and less statistical variance under pulsed conditions when compared to $S{F}_6$. Mixtures of 50%$C_4{F}_{7}N$ with $N_2$ or $C{O}_2$ as buffer gases showed no appreciable difference in pulsed dielectric strength.

Pulsed electron field emission is measured from an assortment of plastic insulators with various surface preparations. The emission is markedly stochastic in nature. Generally, there is a spatially diffuse, baseline level of emission which is observed after a few repeated pulses on a sample. Additionally, localized, highly emissive sites contribute sporadically, with the estimated current for those excitations sometimes exceeding the baseline emission by orders of magnitude. Under 40 ns pulse excitation, Rexolite® produces measurable currents spanning from tens of nA up to hundreds of μA. These measurements mark a first step towards understanding initial plasma formation in anode-initiated vacuum flashover.

This study presents a comprehensive investigation of electrode erosion and discharge behavior in spark gap switches over long switching cycle lifetimes. Brass, copper–tungsten (CuW), and stainless steel electrodes are tested under controlled conditions to quantify material degradation, debris accumulation, and changes in breakdown voltage. High-resolution imaging and statistical analysis of spark channel locations and gap breakdown voltages reveal how surface evolution influences long-term performance and reliability. These results provide essential data for lifetime modeling and inform design strategies for pulsed power systems in emerging applications such as private sector fusion energy and large-scale facilities like Sandia’s Z Machine and proposed ZX upgrades, where high repetition reliability and predictable behavior are critical.