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: Getters, and conflat flanges
Date: Oct 14, 10:39 pm
Poster: Richard Hull
On Oct 14, 10:39 pm, Richard Hull wrote:
I gave extensive discussions on this in a similar vein about two month ago. Check those posts.
Basically the sphere is nice, but welding it is a bear. (no access to the inner surfaces.) Massive modification is impossible. Multiple grids or over sized grids are impossible.
Hemispheres allow more of everything the experimenter wants in spite of the extreme expense.
It is ultimately up to the experimenter.
No A/C compressor will even approach a decent vacuum! A/C maintenance vacuum pumps on the other hand, are mostly good two stage systems and can often hit 20 microns. They cost hundreds of dollars much like scientific pump.
A/c compressors used as pumps barely reach 20,000 microns. A crude demo fusor needs less than 200 microns. At minimum, a good clean two stage vacuum pump of the scientific type is needed.
A getter is of little value even at 0.1 micron!! Most are used to take .00001 microns down to .000001 micron. They usually follow a diff or molecular pump or better still, a cryopumping.