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: Demo fusor
Date: Feb 10, 09:01 am
Poster: Richard Hull
On Feb 10, 09:01 am, Richard Hull wrote:
> Ok on the neutron count, think I will go with
>your second methoed of UHMW since I have access
>to it at work.
> Also have numerous PMT's and coatings.
> Deuterium gas seems to be not a real problem, but
>may have to work a little overtime to pay for it,
> On the inner grid, think I will go with .045
>wire TIG welded and the outer grid 1/16 wire
> You keep scaring me on the deuterium gas. If
>it hits oxygen even at 10^-4mm it ain't going
>to explode is it?? Had a bad experience with
>silane gas that was so recative it would combust
>upon expousture to air!!!
> Hate to keep bugging you Richard, but you seem
>to know what you are doing!
> Hope to have this thing up and running within
>the next month or so.
> Thanks again Bob.
You can use as coarse a wire for the outer shell as you wish. The outer shell can actually be a spherical metal ball! Of course, you will miss out on the display unless you have a viewport.
It is the central grid that is the critical item. On my first fusor I use .026 MIG stainless wire and on my curent one I use .025 tantalum. I have never used 6 great circles for the grids in my system, as Tom Ligon suggests, but have had superb results with only 5. I have tried 3, but the poissor was distorted.
Hydrogen and oxygen have a specific explosive range of mixtures. No, the remaining air in a 10^-3mm exhausted chamber will not react in an explosive manner with the 10^-3mm hydrogen/deuterium inflow. What little water vapor is produced will be hauled out by the pumps.
I would pump the chamber down to 1 micron, shut off the pumps and admit deuterium with the power supplies off to a pressure of 20-100 microns. I would start the pumps again and let the pressure fall to 1 micron and once again shut the pumps off and back fill with deuterium to 10 microns. Now I would apply power very slowly, noting the pressure carefully. If it rises, let it continue until you hit 30 microns It may not get that high though. If it does then start the pumps back up and when down to 5 microns, start leaking in deuterium with power on until a 10 micron pressure is maintained against the running pumps. This is very general and different systems will require different techniques.
It is important to remember that the final run pressure on the fusor is in the 10^-2 - 10^-3mm range (10-1 microns). Ultimately, and hopefully, this will be pure deuterium.
Good luck and let us know how it goes. Make sure you do a lot of runs with air exhaustion only to see the different glow mode regimes.