NAA Tungsten

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.
George Dowell
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NAA Tungsten

Post by George Dowell » Sun Jun 28, 2015 5:59 pm

Newcomers might be interested in this neutron activation experiment. When W-186 (one of the several naturally occurring 'stable' tungsten isotopes) is neutron irradiated some of the atoms pick up an extra neutron to become W-187 which is radioactive and can be measured easily with amateur equipment.

To make it even more interesting, the short half life of about 24 hours is dramatic.

Metal foil activation is directly applicable to Fusors as it is one of the standard primary tool to detect and measure neutron flux.

As this experiment develops, updates will be posted in this remote folder:

http://www.qsl.net/k0ff/01%20Nuclear%20 ... ctivation/

George Dowell

edit 5July2015- added Am-Be document
Attachments
Am-241 Neutron Sources.pdf
Am document
(3.86 MiB) Downloaded 134 times
Two-12Hr-Runs-24Hrs-ApartW-187-HighlightedPub.jpg
edit- better picture with two 12 hour scans, 24 Hr apart.
Last edited by George Dowell on Sun Jul 05, 2015 1:45 pm, edited 4 times in total.

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Richard Hull
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Re: NAA Tugnsten

Post by Richard Hull » Mon Jun 29, 2015 3:49 pm

Nice plot of the activity for the activated W. Most fusors can't run long enough to activate Tungsten noticeably wihtout a special high sensitity gamma spec or GeLi detector. We tend to stick with Silver, Indium, Manganese and a couple of others with high cross section and very short half lives under 10 minutes or so. Rhodium would be fabulous if you could get enough to play with.

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
Retired now...Doing only what I want and not what I should...every day is a saturday.

Peter Schmelcher
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Re: NAA Tungsten

Post by Peter Schmelcher » Tue Jun 30, 2015 3:44 am

George I ran across your site searching for GR-130 DOS software some time ago, a big thanks for making it available. With the software I was able to understand the file format for a custom nuclide identification library, honestly, it is something that should be done in a desktop but I had fun doing it just the same.

I have been wondering if gamma rays transfer energy to atoms in an all or nothing kind of way, or if they can be somewhat moderated. Do a few inches of lead widen the Full Width Half Max of a gamma peak and is there any chance of detecting a 6MeV gamma with a 3MeV instrument?

Thanks
Peter

George Dowell
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Re: NAA Tungsten

Post by George Dowell » Tue Jun 30, 2015 1:38 pm

Hi Peter, please send me a direct email so we don't clutter up the board with non fusor stuff.

George Dowell

GEOelectronics@netscape.com
Peter Schmelcher wrote:George I ran across your site searching for GR-130 DOS software some time ago, a big thanks for making it available. With the software I was able to understand the file format for a custom nuclide identification library, honestly, it is something that should be done in a desktop but I had fun doing it just the same.

I have been wondering if gamma rays transfer energy to atoms in an all or nothing kind of way, or if they can be somewhat moderated. Do a few inches of lead widen the Full Width Half Max of a gamma peak and is there any chance of detecting a 6MeV gamma with a 3MeV instrument?

Thanks
Peter

Roberto Ferrari
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Re: NAA Tungsten

Post by Roberto Ferrari » Tue Jun 30, 2015 2:13 pm

Hi George

Having so low counts, I see a risk of electronic drift.
Can you design the experiment in order to avoid any changes in response?

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Richard Hull
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Re: NAA Tungsten

Post by Richard Hull » Tue Jun 30, 2015 7:21 pm

Remember, this forum is all about radiation detection. Not just neutrons. Gamma Spec talk is always welcome as that is how we work with activated materials for identification.

GM counters, PMTs, Neutron detection counters or methodology are all viable in this forum. Fusion radiation detection efforts are very diverse and most radiation topics can readily be discussed here. As long as they can be used in part or fully for detection of fusion or radiation found in activation products.

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
Retired now...Doing only what I want and not what I should...every day is a saturday.

George Dowell
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Re: NAA Tungsten

Post by George Dowell » Tue Jun 30, 2015 7:31 pm

Thanks for the clarification Richard.

I'm interested in all aspects of nuclear and atomic ionizing radiation and electromagnetic non ionizing radiation detection and shielding.

George Dowell
Richard Hull wrote:Remember, this forum is all about radiation detection. Not just neutrons. Gamma Spec talk is always welcome as that is how we work with activated materials for identification.

GM counters, PMTs, Neutron detection counters or methodology are all viable in this forum. Fusion radiation detection efforts are very diverse and most radiation topics can readily be discussed here. As long as they can be used in part or fully for detection of fusion or radiation found in activation products.

Richard Hull

George Dowell
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Re: NAA Tungsten update: 4 half-lives later

Post by George Dowell » Thu Jul 02, 2015 4:12 pm

picture shows the first 12 hour scan and another 12 hour scan after 4 Days= 4 half lives of W-187.



George Dowell
Attachments
Run#3-VS-Run#18-12Hrs-4DAYS-AparAnnotated-Cropped-PUB.jpg

Roberto Ferrari
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Re: NAA Tungsten

Post by Roberto Ferrari » Fri Jul 03, 2015 12:46 pm

George
Those spectra are the best answer to my question.
Congratulations!
Roberto

Jon Rosenstiel
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Re: NAA Tungsten

Post by Jon Rosenstiel » Fri Jul 03, 2015 8:50 pm

Very nice work George... nice clean spectra. What are you using as a neutron source?

Jon Rosenstiel

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