Breakdown Processes in Laser-Triggered Switching
Abstract
Time-resolved optical diagnostics of coaxial laser-triggered (Nd:YAG, 1.06 micro) nitrogen filled spark gap operation have shown breakdown to result from a laser assisted streamer propagating from the laser fireball to the opposite electrode. Streak photography shows that the streamer precursor of the breakdown channel initially proceeds across the gap at about 10(expn 8) cm/sec, but slows to about 2 x 10(expn 7) cm/sec as it advances in the focal cone to regions of lower laser intensity. The laser interaction with the streamer produces a relatively uniform, resistive channel which is then rapidly heated ohmically until the gap voltage collapses, and intense continuum emission is produced. When the streamer transit time is greater than the laser pulse length two distinct regions can be detected in the arc channel: one laser assisted, showing the abrupt appearance of continuum luminosity, and the other not laser assisted, appearing much like a weakly overvolted breakdown event.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1983
- Accession Number
- ADA638399
Entities
People
- A. H. Guenther
- P. F. Williams
- Roger A. Dougal
Organizations
- Air Force Research Laboratory