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: Copper spheres as vacuum vessels, anodes
Date: Jan 25, 4:37 pm
Poster: Richard HullOn Jan 25, 4:37 pm, Richard Hull wrote:
All,
Any vacuum worthy metal spherical system will work just fine. Stainless steel is just more vacuum friendly in terms of out gassing at really low levels, weldability for really high temps, etc.
The electron beams heat the walls in a severe manner,locally. Copper is nice in that it conducts heat way and evenly distributes it very well. Stainless is very poor in this regard. It can take much more heat though. Copper can only be soft or silver soldered, with silver soldering the preferred method. Still, most silver solders soften around 800 deg F. As with anything it is a trade off to be ultimately decided by the user.
My stainless fusor III will quickly coast up to 110 degrees F above ambient, (That's about 180 deg. F. at room temperature), when running at 15KV across chamber. ( I have a K type thermocouple meter attached.) This will severely burn the hand if not touched very gingerly.
The first three inner grid loops at 120 degrees can each be fashioned like a hand held mirror with the loop ending in two, touching, downward extended stalks and the three grid hoops assembled and silver soldered together at the 6 stalks. These can double as a mounting arrangement, especially if finished off by dropping the soldered stalk group into a short length of SS or brass tubing and silver soldering to form a nice cylindrical base.
Still, three rings, fully closed, might have to be used for the final outer rings of the small inner grid geodesic. Ultra fine wire can be used to lash the intersectional points of grid wires together and silver solder would wick in and hold the assembly very fast.
Richard Hull