Speaker
Description
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 trend, plastic insulators exhibit superior high voltage hold off characteristics [1] whereas ceramic and glass insulators have superior vacuum outgassing properties. As a result, systems with high field stress requirements tend to use materials such as Rexolite or PMMA [2]. Systems with stringent vacuum requirements are often designed with ceramic insulators [3] and are designed with low electric field stress. A plastic with high electrical strength and low outgassing may provide advantages for applications where low vacuum outgassing is required. In this study we compare the electrical and vacuum performance of Rexolite, a pulsed power industry standard vacuum insulator, to Kel-F (PCTFE), a plastic with significantly lower vacuum outgassing [4]. Tests were conducted with 7-mm thick insulators with a $45^{\circ}$ frustum. The applied voltage pulses have a FWHM of $\sim$100 ns and peak voltage up to 350 kV.
[1]. O. Milton, IEEE Trans. Elec. Insul., EI-7, pp.9-15, (1972).
[2]. W. A. Stygar, et. al., Phys. Rev. ST-AB, 8, 050401, (2005).
[3]. W. L. Waldron, et. al., Proc. IPMHVC, pp.179-182, (2000).
[4]. S. Simpson, “Vacuum Outgassing Study of Candidate Materials for Next Generation Pulsed Power and Accelerators: Improving the Boundary Conditions for Molecular Flow Simulations”, Companion Talk, this Conference (PPPS 2019).
- Sandia National Laboratories is a multimission laboratory managed and operated by National Technology \& Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
