Cs137 Questions

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
Post Reply
Tom Dressel
Posts: 287
Joined: Fri Jun 22, 2001 4:44 pm
Real name:

Cs137 Questions

Post by Tom Dressel »

I think I can get a few tenths of a microcurie of Cs137 from one of the nuclear med physicians at the hospital where I spend most of my time. The question is: is this enough activity to set the discriminator levels on the BC-720 based PMT neutron detector?

Tom Dressel
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Cs137 Questions

Post by Richard Hull »

I would think barely able to do that. The 661 kev gamma from Cs 137 is pretty hot and is penetrating enough, but only a close up test will tell.

You would have to run a long, long background run, record the result and then jam the source up against the scintillator and see if any differential is noted. If there is, you will probably be OK. Just dial the discriminator back to achieve the background just taken.

Ideally, you want a pretty hot Gamma source of 10 or more microcuries. But few have such a source.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Tom Dressel
Posts: 287
Joined: Fri Jun 22, 2001 4:44 pm
Real name:

Re: Cs137 Questions

Post by Tom Dressel »

Thats what I thought.

I may be able to borrow a hotter source, but the Nuke Med guys are kind of "anal" about letting anything out of the hospital.

Tom Dressel
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Cs137 Questions

Post by Richard Hull »

The best and hottest sources are old WWII aircraft instruments. You can even leave their faces on for gamma ray purposes. Many of these instruments have 10's of microcuries in them. They can be found at many hamfests and had for a few dollars, although recently they are conspicuous by their absence! I see a lot of them sold on E-bay just for the rad goody!

These make good, safe, hot and handy sources provided all is left as found.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Post Reply

Return to “Neutrons, Radiation, and Detection (& FAQs)”