Conveners
5.5 Insulation and Dielectric Breakdown II
- Guy Rosenzweig (Massachusetts Institute of Technology)
High voltage vacuum insulation is a key component of many high voltage and pulsed power systems. High voltage vacuum insulator performance has been investigated for a variety of materials, geometries, and pulsed voltage duration. Experiments have shown that a $45^{\circ}$ frustum with the base at the cathode is typically the ideal shape to optimize electrical performance. As a general...
Next generation pulsed power machines and accelerators require a better understanding of the materials used within the vacuum vessels to achieve lower base pressures (P << $10^{-5} ~Torr$) and reduce the overall contaminant inventory while incorporating various dielectric materials which tend to be unfavorable for UHV applications. By improving the baseline vacuum, it may be possible to delay...
Recent work by our group, presented at ICOPS Denver and subsequently published[1], demonstrated an effect of temperature on the breakdown voltage in argon between two spherical electrodes at elevated pressure. Experiments in this work were done in a closed vessel, and the result was an augmentation in the breakdown voltage with increasing temperature for a given gas density. This result is in...
Low-loss or loss-free constant-impedance magnetically insulated transmission lines (MITLs) are well understood and are successfully used on the very largest pulsed-power drivers such as Sandia National Laboratories Z Machine. Next-generation drivers must optimize MITL designs to lower their inductance and increase the current per MITL. Super-insulated MITLs are well understood from a...
RF breakdown at 3.3 MHz is studied experimentally in centimeter sized gaps at atmospheric conditions. As a point of comparison, unipolar breakdown voltages utilizing brass and stainless-steel Bruce profile electrodes are measured to compare with RF breakdown. Various electrode combinations using brass and stainless-steel electrodes were tested, where brass cathodes yielded higher shot-to-shot...
Pure N2 and SF$_{6}$ as well as their mixtures are evaluated for high electric field breakdown tested at pressures ranging from 756 torr up to 1655 torr at 2.85GHz. Previous research concerning the breakdown characteristics of pressurized SF$_{6}$ and SF$_{6}$ mixtures at S-Band frequencies is limited, likely due to the high electric fields required to breakdown pressurized SF$_{6}$. A stepped...
Surface flashover across solid dielectric/gas interfaces is a problem that can occur during operation of gas-insulated high voltage (HV) equipment. The present work is aimed at investigation of the surface flashover characteristics of different solid dielectrics and surface topologies, stressed with HV impulses in air at different pressures. An experimental system has been developed to control...
