Diffuse discharge switches

Dissociative attachment processes are important for the efficient operation of diffuse discharge switches in inductive energy storage circuits. Attaching gases with low attachment rate at low values of reduced field intensity E/N and high attachment rate at high values of E/N allow the discharge to operate with low losses in the conductive phase and to achieve fast opening after the e-beam is turned off. Such attachers generate a voltage-current characteristic of the discharge with a negative differential conductivity (NDC) range. Experimental results with mixtures of C/sub 2/F/sub 6/ and Ar where the voltage-current characteristic exhibits a very pronounced NDC are presented. The design of e-beam controlled switches will be discussed, including the electron gun system, choice of gas mixture and pressure, and the design of the switch chamber. Diffuse discharge switches studied at various laboratories are compared with respect to important switch parameters, such as switch current density, current gain, voltage stand off, conduction and opening time. Concepts for e-beam sustained, optically controlled switches are presented and the limitations of diffuse discharge switches are discussed