After a bit of tuning, results were improving. It was still running at 50v input because even at that low voltage, it was drawing 4A and my control box was only built for 5! Rebuilding the control box will have to be done next so that I can increase the power further.
Brush discharges. Without an arc to draw the current, the high voltage charge escapes as a fine blue brush with a hissing noise. It likes sharp points, the lower discharge is coming from the edge of the metal tape holding the pin on. The upper discharge is from an earthed wire and is being drawn towards the pin.
Arcs – A lovely 40mm arc, being drawn between an earthed wire and the discharge ball. It makes a deep crackling noise and generates a vast amount of heat. After 10 seconds, the plastic insulation on the earthed wire starts to melt.
Plasma. A poor 40w light bulb getting it’s gas ionised into plasma. This effect was created at only 20v input, any higher and the glass bulb gets too hot ! This is a very satisfying effect and the plasma can be attracted to the hand (carefully!) although even at this power, the glass still gets hot.