High dielectric constant materials for pulsed energy storage capacitors

A high dielectric constant coupled with a high dielectric strength is essential in producing high energy density, low inductance capacitors used in pulsed energy systems. The NLC (Next Linear Collider) which is envisioned as the next step in high energy physics research tools will employ several thousand pulsed klystron RF sources. The modulators for these klystrons require efficient, reliable energy storage capacitors. Collaboration with Russian scientists has made available to us information and capacitor samples based on the Tungsten-Bronze family which exhibit dielectric constants of over 1,000, and working voltage gradients in excess of 60 kV/cm. We are currently testing 10 nanofarad, 40 kV capacitor samples in pulsed modulator service manufactured at the GIRIKOND Institute in St. Petersburg, Russia. Dr. Galina Blokhina is the designer of these capacitors. The material is a solid solution of complex compounds of niobate dielectric. The Tungsten-Bronze-Type Crystals are bound in amorphous glass. The paper summarizes the theoretical studies of this material with a Russian and English bibliography, describes Dr. Blokhina's manufacturing processes, and presents the results of pulsed energy storage testing carried out at SLAG for the NLC R&D effort. It is the intent of this paper to spark interest in transferring this technology to the world community so that R&D in this area will expand and provide this technology to many users including the NLC project.