Search found 2329 matches

by Carl Willis
Wed Sep 04, 2002 1:44 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: New mini neutron detector from U of Nebraska?
Replies: 5
Views: 1848

Re: New mini neutron detector from U of Nebraska?

<t>Because of the tiny dimensions of the available single-crystal, relatively defect-free SiC, I doubt it would be useful for neutron detection. <br/> <br/> However, I have tried some experiments with SiC rectifiers sold by MicroSemi to see if they will work as beta detectors. No luck. I reverse-bia...
by Carl Willis
Wed Jul 10, 2002 6:15 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Homebrew neutron test sources
Replies: 3
Views: 2070

Re: Homebrew neutron test sources

<t>Larry,<br/> You're right that this stuff has been covered (and better than I remembered it, so most of my questions have been answered)! Richard Hull's "Scintillator Test" post from April actually describes that the paint was not scraped off his instrument needles...and also there is an estimate ...
by Carl Willis
Tue Jul 09, 2002 9:19 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Homebrew neutron test sources
Replies: 3
Views: 2070

Homebrew neutron test sources

<t>A while back, Richard Hull mentioned his methodology for comparing neutron pulses from the Tom Dressel vs. Bicron scintillator units, including a brief statement and a caution, I believe, about the making of a simple RaBe source from radium paint and beryllium. (This source is not very hot in ter...
by Carl Willis
Thu Jun 13, 2002 7:59 pm
Forum: Vacuum Technology (& FAQs)
Topic: What happened to "The Bell Jar" Online?
Replies: 2
Views: 1951

What happened to "The Bell Jar" Online?

<t>Does anyone know what is going on with the website for "The Belljar" (You know, that great amateur vacuum journal)? For quite a while now it seems to be gone from its previous location. I'm not a subscriber to the printed journal but I do look at the good stuff online from time to time. Any clues...
by Carl Willis
Tue Feb 12, 2002 7:04 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Spot Welding Success!
Replies: 1
Views: 1827

Spot Welding Success!

<t>Yes, I'm aware this has been a trivial issue for just about everyone else. But the spot welding problem has been frustrating me for a long time, until this week when a surprisingly crude lashup of capacitors and a transformer did an awesome job of assembling my first fusor grid. The welder is com...
by Carl Willis
Tue Feb 12, 2002 6:39 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Source
Replies: 11
Views: 4630

Re: Neutron Source

<t>Perhaps the Po-210 antistatic brushes are worth mention as energetic alpha emitters for possible alpha / Be neutron sources available to anyone (they are under general license in the US). They are manufactured by NRD Corp. and sold by such online dealers as SPI Supplies and Warehouse Photo for ~$...
by Carl Willis
Wed Sep 26, 2001 8:54 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Re: gamma spectrogram
Replies: 2
Views: 2037

Re: gamma spectrogram

<t>Nice spectrogram Richard. I'm considering the options of either purchasing or building a PMT and NaI detector, and was wondering what you are using. I have read that the big ones have trouble with energy resolution unless very carefully assembled, and these are extremely expensive (they abrade th...
by Carl Willis
Thu Sep 20, 2001 4:17 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Spot-welding cathode grids
Replies: 10
Views: 4442

Re: Spot-welding cathode grids

<t>Richard, I'm still a bit frustrated by trying to spot-weld. Good suggestion about the welding electrodes- I got some at McMaster-Carr and they did improve my success ratio. But I may not have the right technique yet. This is what I do when I try to make a closed loop: I clamp the wire so the free...
by Carl Willis
Thu Sep 13, 2001 1:31 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Spot-welding cathode grids
Replies: 10
Views: 4442

Spot-welding cathode grids

<t>Hello everyone,<br/> <br/> My fusor is all built except for the cathodes (maybe I'll post pictures shortly) so I'm at the point where I need to learn how to spot weld cathode grids. I have tried to weld stainless wire with a 50-amp welder, and have made only one good weld out of about six attempt...