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: Few fusor questions...
Date: Apr 01, 0:49 am
Poster: Dave Cooper
On Apr 01, 0:49 am, Dave Cooper wrote:
>>I'm using plumbing for the system (which will be running on normal air) which is not made of stainless steel, so I'm worried about it outgassing. What I'm currently using is cast iron plumbing, but I might have to live with brass.
>Cast Iron and brass aren't particularly wonderful..
>I believe the Handbook of Chemistry and Physics has a table with outgassing rates for a number of materials.
As a first approximation, the outgassing rate of a metal under vacuum, is inversely proportional to the time of pumpdown. (ie: a decade increase in pump time results in a decade reduction in outgassing rate.) Almost any amount of bakeout will be beneficial. If you are patient, bakeout at 90C to 120C for about a full day (at least over night) will usually get your system reasonably clean and free of water.