Compact pulsed power using solid dielectric transmission lines

This paper documents recent work developing solid dielectric transmission lines for sub-microsecond, 100 kV class compact pulsed power systems. Recent developments in nano composite and ceramic dielectric materials processing have opened new possibilities for using transmission lines in compact pulsed power systems. These material systems span wide ranges of permittivity, dielectric strength, and practical operating voltage, all of which are combined to deliver the desired electrical pulse to the load. Recent work has focused on polymer-ceramic nanocomposites and TiO2 based ceramics which have relative
permittivities of approximately 50 and 140, respectively. The corresponding propagation velocities in the dielectric are 4.2 and 2.5 cm/ns. The descriptor “compact” is a function of the application, and while a flat transmission line may satisfy some applications, folding the lines offers some different possibilities,
including delivering pulse lengths up to several hundred ns with a largest dimension less than 1 m. Marxed capacitor banks are routinely used to scale the voltage from standard power supplies to 100’s of kV without the use of a pulse transformer. Marxed operation is applied to the transmission line development
described here.

Theory, simulation, and fabrication techniques were incorporated into the design of flat and folded transmission lines. The experimental evaluation of the lines progressed from low to high voltage and from single lines to a Marxed configuration of several lines. This paper presents the recent results of this
development effort.