Ultraviolet LED Triggered Spark Gap

We present progress towards a novel spark gap switch triggered by light from an LED. Pulsed light at 275 nm is focused on the electrodes to seed breakdown via the photoelectric effect. In order to understand the operation and limitations of the device, we include the photoelectrons as a low energy beam in a streamer breakdown simulation. We plan to integrate a local electron source term into a conventional two-fluid model using the Afivo framework [1]. We expect negative streamers to form at lower voltages than are typically observed due to electric field enhancement from the locality of the source and the non-neutral nature of the beam. We describe our experimental setup and observations, as well as preliminary interpretations of the physics guided by simulation.

[1] Teunissen and Ebert 2018. Afivo: a framework for quadtree/octree AMR with shared-memory parallelization and geometric multigrid methods. Comput. Phys. Comm., 233 (2018), pp. 156-166.