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.
Date: May 18, 10:17 am
Poster: Richard Hull
On May 18, 10:17 am, Richard Hull wrote:
I have been having a lot of trouble hitting the one micron mark with my vacuum system for neutron production. Pumping has been slow or poor. I finally ran a fusion run the other weekend, and only achievied 18,000 neuts/sec. I have done better. I discovered the reason for the problem. I had a micro leak develop around my view port viton gasket. I took the fusor apart and also the view port. The glass was damaged from February, (though not leaking or cracked). It was also very heavily deposited making a neutral density filter out of the pyrex window.
The big suprise came when the gasket was examined. It seems that I had really over tightened the port bolts and some of the gasket oozed into the chamber area. Electron bombardment had dryed and charred the gasket to a hard wood like substance. The gasket was split open and the micro leaks developed around it. I have decided to use elemental indium wire to seal the replacement window.
I am also going to have to re-orient the inner grid on its post. I originally aligned it for appealing photo images of the beams. This had me looking right into the center of an open wire square. The star beam ray stuck the window dead on. (The rays always exit center of the opening in the inner grid.) I must now unbraze the inner grid and realign and braze so that a wire is dead center or bisecting the center of the viewport. I'll still get deposition over time, but not a beam blasting a hail of charged particles at full machine energy.
I am also spending a huge amount of time machining and welding stainless vacuum materials needed to adapt a mambo turbo-pump I picked up in January. This is a real tale in itself.
I was at a hamfest selling my tapes, elements, vacuum pumps and showing off the fusor. An old man came by saying he had a friend who was looking sell a gang of vacuum stuff. Ultimately, his friend called me and I obtained an 1800 liter per second turbo pump and controller by Airco Temescal. It has an 8" throat!!! This is massive beyond belief. Most small turbo systems use a 2,3, or 4" maximum orifice and are in the 100-300 L/S range and cost 3,000 to 6,000 USED! (see the Duniway catalog).
I have spent about 2 months testing the controller, It works great. The pump is free turning and begins to wind up on the controller. (Never run a turbo against air!). I am now assuming the system is fully functional. Another hassle with these big guys is the demand for water cooling. (flowing water needed) I would have had to do this part anyway with a diff pump so this is no super hassle.
The hassle is the need for a 13" diameter stainless blank off plate with "choke down tube."
I found a 1" thick stainless 14" diameter blank off in a scrap yard for $30.00 (high pressure plate). I have spent two weekends and a gang of weeknights facing it, boring the 8 bolt holes to adapt to the pump and boring and welding a 1.5" central pipe with a 2.75 conflat. I am nearly ready to test this out. I may put the repaired fusor III on this thing which should suck a golf ball through a garden hose.
This will be nirvana from a vacuum point of view, but overkill to say the least. It is sort of like making an adapter for hooking a normal vacuum cleaner hose to the air intake of an F-15 to vacuum out a dusty shoe box!
The normal USED price of such a pump as this, with controller, is in the 10-12 kilobuck range. I paid $100.00!
Soooo! I'm not currently fusin' and doubt I'll be fusin again for a short while. The new power supply works great. Corona is totally suppressed in the oil tank.
When I come back on line, I hope to attack the 100,000 neut per second barrier. Somebody might beat me to it if I dawdle or putz around too long.