High-Energy-Density Storage Capacitors

Pulsed Power delivery has been an ongoing development area for DOE for a number of years, since the klystron modulators represent a substantial segment of the budget for any new accelerator, synchrotron, or light source. DTI has been at the forefront of this development, and has fielded hundreds of high voltage systems using IGBT switches with dramatically higher reliability, and compact size. The capacitors used in these systems, however, have not seen a similar level of development, and now dominate the size of the modulators. Our intent is to increase energy density of capacitors without compromising lifetime and reliability. Development of a higher density, high voltage capacitor would allow both longer pulses, and more compact klystron modulators for these future systems. Although high density capacitors are available today, their life is completely inadequate for an accelerator application. These capacitors cannot sacrifice reliability for density. We propose to work together with CSI Technologies to develop high energy density, high voltage capacitors using new capacitor architecture. DTI and CSI will design, build, and test prototype 0.5 J/cc DC capacitors based on propylene hazy film with 5 times the energy density of existing CSI capacitors. We will investigate other design approaches and study and characterize capacitor failure modes to determine accurate lifetime models of the capacitors. Commercial Applications/Benefits: Developing capacitors and capacitor banks with a higher energy density, longer life, and a higher degree of operating safety with have significant benefits to future pulse power systems, for high energy physics, military, and commercial applications. These benefits primarily translate to compact modulator designs, which are desirable in all applications, and becoming critical for linear accelerators (such as ILC and ESS) and future military systems (electromagnetic launch, airborne laser, etc.).