Fusor Forums

http://www.keelynet.com/interact/archive/00002072.htm

Neutron detector? No, I don't think so... What the author describes is a simple 1-turn pickup loop, 10k termination, coupled to an amp and/or counter. Unless this is picking up charge from alpha or beta decay, I don't see how it can detect radiation at all. I don't even see how it can pick up charge with a 10k termination. If one had the components lying about, it would be easy to try for a laugh. The worst it could do is fail.

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Keelynet....umm..err...well..you know
Thought there are some interesting things there.

Adam

The cheapest way to build a neutron detector is with Silver and a cheap gieger counter. Neutrons will activate the Silver and you can use the geiger to detect the activation. For Silver, you can use an old coin (Silver dollars, half-dollars, or a bunch of dimes dated pre-1960's). Or you can order silver coins or bullion from the web. To block X-ray, or natural radioactive emissions, you could probably use an old or cheap stainless steel pot with a small hole in the side or top for the cable. The stainless should block out most of the x-rays and natural radation. To improve sensitivity fill the pot with wax or some other hydrogen rich material as a moderator.

Cheap Geigers can be found on ebay all the time.

i've been toying with a similar idea.
take a gm tube and wrap a layer of indium foil over it. then place in a suitable container and fill with parafin or other moderating substance.
to block x and gamma i was going to use several layers of lead foil around the outside of the assymbly.
not the best of detectors, but if it works, it is a simple solution.

Q

Geiger counters!? Activation?! What a great idea! (tongue in cheek)

As long as you have millions of Neuts per second, this is just marvelous.

This has been done by only two folks I know of here who have show it to work. Both have killer fusors. Indium is the best activation material. Silver needs a lot more thermal neutrons.

Silver resonances will capture some few epithermals as it has quite a confusion of massed of resonances.

In some cases with careful countingstatistics, moderated fast neutron blasts as low as 200,000/sec will activate.

You certainly can't use activation at low neutron flux levels for baseline detection of minimalist fusion.

Richard Hull

The bottom line with any technology, is if is really simple and cheap its isn't going to be precise or sensitive. If you need sensitivity the BF3 or HE3 tube is the best low cost option. My advice is keep watching EBay for a tube to come available. I bought a 1 foot BF3 tube for $50 on Ebay about 6 months ago,. Brand new and still sealed in box! althought, I haven't found time to find a good detector or time to build my own detector for it.