Electrode Material Comparison for Potential UV-Triggered Spark Gap

We present progress towards a UV-LED-triggered spark gap as part of our search for a relatively inexpensive solution for fast high-voltage switching (rise times of GV/s). The challenge lies in the uncontrolled timing that is characteristic of spark gaps. Current methods involve pricey laser-triggered spark gaps, which use photoionization to solve the timing jitter. This project evaluates the feasibility of triggering the spark gap through photoemission from the cathode instead. We use a pulsed 270nm LED to eject electrons from the cathode in hopes of seeding a sub-threshold discharge. We present the current status of the project and questions that remain to be answered. In particular, we address the duration and energy of the UV pulses and compare the performance of varying electrode materials with different work functions.