Energetic ions are attracted towards the central electrode, and when they hit that graphite stick...

Energetic ions are attracted towards the central electrode, and when they hit that graphite stick that I put in the centre, you see a wonderful mini-explosion from the collision. This all took place in a vacuum chamber at high voltages (ZVS circuit is the driver). The best view of it is at roughly 50 seconds into the video. https://blossom.primal.net/17d7a9840f08f819c54671d37884c4dd644374ec447b757ca9f2197a967d94e2.mp4