In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.Subject: Re: Vacuum Bell Jars
Date: Apr 12, 2:34 pm
Poster: Jim LuxOn Apr 12, 2:34 pm, Jim Lux wrote:
>Looking for HIGH vac bell jar - Richard has said that he uses models from Fisher Scientific Nagalene - not glass... I didn't see anything in their catalogue that seemed to fit the bill for a high vacuum application... Rich seems to think glass too dangerous... Looking for 12" to 13" diameter range... Looked at "Laskey" (? or something like that web-page.. They have glass bell-jars, but don't specify their vacuum range... )
All glass bell jars go to high vacuum. The mechanical stresses aren't appreciably different once you get below a few torr. There are two problems with glass bell jars in a fusor: 1) No inherent soft xray shielding; 2) The possibility of electron beam heating of a spot, weakening it.