Spark Column Plasma Dynamics Model (A First Principles Model for Laser Triggered Spark Gaps)
Abstract
In a laser triggered spark gap (or spark column) breakdown is initiated by a laser which creates a narrow preionized column between the electrodes. This small plasma column, expands to an arc with a diameter of 0.5-1.0 mm on a time scale of 100 ns, and is capable of carrying a current in excess of 10 kA. During the expansion phase, the resistance of the plasma column decreases from many kilo-ohms to as little as a few tenths of an ohm. For many applications, the duration of the current pulse through the spark gap is only 100-200 ns and therefore is commensurate with the time required for the plasma column to expand. Therefore during the time of interest, the spark column changes from being a dominant resistive loss to being a lossless circuit element in comparison to the load. In order to optimize the performance and minimize the losses, of laser triggered spark gaps operating under these conditions, it is desirable to have a detailed understanding of the physics of the expansion phase of the spark. This report summarizes the first phase of development of a model to achieve that goal. We discuss a model which, from first principles, describes the growth of the arc in a laser triggered spark gap in a gas mixture of a noble gas and a diatomic molecules.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1984
- Accession Number
- ADA147954
Entities
People
- M. J. Kushner
- R. D. Milroy