Study of laser target triggering for spark gap switches

• Published in: IEEE transactions on dielectrics and electrical insulation Vol. 16; no. 4; pp. 956 - 960
• Main Authors: Sullivan, D.L., Gahl, J.M., Kovaleski, S.D., Hutsel, B.T.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-08-2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Cathodes; Durability; Electric power generation; Gas lasers; gas switches; High voltages; Jitter; laser ablation; Laser targets; Laser triggering; Lasers; linear transformer driver; LTD; Melting points; Optical materials; Optical pulses; Optical reflection; Plasma materials processing; Plasma waves; Sparks; Switches
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2009.5211839

The use of laser targets as a method to decrease the required laser energy to trigger a laser triggered gas switch has been investigated at the University of Missouri. Target materials were identified based on durability, melting point, reactivity and reflection coefficient. Laser targets were placed into a cathode of a laser triggered gas switch. The switch was pulse charged by the Tiger pulsed power machine to between 185 kV and 330 kV. The switch was triggered by directing a 1064 nm or 266 nm wavelength laser pulse from an Nd:YAG laser onto a laser target to ablate material and create plasma, closing the switch. The goal of the project was to trigger a high voltage gas switch with less than 1 mJ of laser energy while maintaining a switch jitter comparable to present electrically triggered switches for LTD based systems. The study successfully demonstrated that triggering the switch using a 1 mJ infrared pulse and a graphite target resulted in a jitter less than 5 ns. Findings will be used in the design of switches for LTD based systems.