Development of a 200-kV Test Stand and Experimental Study of Optical Triggering Methods for LTD Switches

• Published in: 2008 IEEE International Power Modulators and High-Voltage Conference pp. 443 - 446
• Main Authors: Sullivan, D.L., Kovaleski, S.D., Hutsel, B.T., Gahl, J.M.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2008
• Subjects: Capacitors; Gas lasers; Laser ablation; Lenses; Optical materials; Optical pulses; Optical switches; Power lasers; Runtime; Testing
• ISBN: 9781424415342; 1424415349
• ISSN: 1930-885X; 2576-7283
• DOI: 10.1109/IPMC.2008.4743685

A 200-kV test stand is being developed at the University of Missouri to examine optical triggering techniques for LTD switches. Two capacitors, separated by an optically triggered switch, are DC charged to plusmn100-kV. The switch will be triggered by a pulse from an Nd:YAG laser at 266, 532, and 1064-nm wavelengths. The goal of the study is to find methods to reduce the optical energy required to trigger the switch while minimizing runtime and jitter. To reduce laser energy, several methods will be explored. One method is to identify candidate materials based on their respective work functions and apply them to the switch cathode. Laser light will be directed onto the target materials with intensity below the ablation threshold, liberating electrons. Another method is to create a laser spark created in the mid-gap of the switch while manipulating length, position and orientation through control of laser power, focusing lenses, lens positions, insulating gas composition and photon energy. Findings will be used in designing of future LTD switches and triggering systems.