Fusor Forums

Since I have some down time waiting for Columbus-I pinch tube supplies, I decided to fire up the old demo Fusor. In this pic its operating at 60 mTorr around 7kv (ballasted 15kv NST). The classic star mode is just beginning to form (along with those annoying and dangerous electron beams). In the next few days I'll clean everything up, install a better outer grid, and get the diff pump up and running.

Mark Rowley

Mark, great to hear from you and see the old bell jar back in business. I found that in fusor II bell jar, at about 10-15 microns the beams are highly prominent and I started to get the borosilicate glass glowing first orange and then yellow hot at the pinpoint of beam impact. I never ran it so long as a rule.

I think I first did fusion in my bell jar at 25kv. (no measurement taken in late 1997), but freaked out when one of the yellow hot beams had a thin,1/2-inch diameter chunk of glass flake off the inside of my bell jar. I immediately ceased all fusor II work and started building fusor III in Stainless steel.

Keep us up on your bell jar effort once cleaned up and squared away. It is tough to beat a nice view of a clean star mode in a bell jar as long as you don't go at it too long. Just do it long enough to get come fabulous pix. With a neon sign xfrmer you might not have to worry about the heating that much.

Richard Hull