Identify the isotopes

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.
Jon Rosenstiel
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Identify the isotopes

Post by Jon Rosenstiel » Wed Nov 17, 2010 11:46 pm

Here’s something for all you gamma spectrometrists out there to hone your skills on… ID the peaks to see what makes this sand radioactive.

Photopeaks in the attached Excel file are within 0.5 keV (hpGe is awesome!) so searching out the correct radionuclide shouldn’t be too difficult, but beware, there are a few peaks that will probably make your head hurt!

My favorite on-line search site is: http://nucleardata.nuclear.lu.se/nucleardata/toi/
Click on “Radiation search” and in the next window that comes up enter the peak value in the energy box and 0.5 in the plus/minus box and click “Search” to bring up a table of likely suspects within the range specified on the previous page.

Hmmm, the Excel file wouldn’t attach here so I placed it in the files section, link here: http://www.fusor.net/board/viewtopic.ph ... 014#p57418

Have fun…
Jon Rosenstiel

PS: Does anyone know how I can attach the Excel file here? Size is 1.1 Mb.
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Steven Sesselmann
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Re: Identify the isotopes

Post by Steven Sesselmann » Thu Nov 18, 2010 6:40 am

Jon,

This is impressive...., the resolution is as good as in the Heath catalog.

You didn't mention why the sand was active...did you cook it in your neutron oven?

Steven

PS: I am interested in learning how you came up with the formula on your spread sheet to convert bins to KeV
http://www.gammaspectacular.com - Gamma Spectrometry Systems
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Jon Rosenstiel
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Re: Identify the isotopes

Post by Jon Rosenstiel » Thu Nov 18, 2010 4:13 pm

Hi Steven,

The sand is naturally radioactive; it is left to the reader to identify the radionuclides present. See: http://en.wikipedia.org/wiki/Decay_chain
Thorium series? Neptunium series? Uranium series? Actinium series? Or a combination?

As to the energy calibration... It starts with this program: (Written by one of your fellow countrymen).
viewtopic.php?f=19&t=7958#p57362
After using the program for some years I discovered it only calculates out to a couple of places so I wrote a small macro to do the energy calibration in Excel.
If you'd like more info please email me.

Jon Rosenstiel

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Richard Hull
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Re: Identify the isotopes

Post by Richard Hull » Thu Nov 18, 2010 9:08 pm

Living within 30 miles of the Ligon mine in Amelia VA, this is monazite sand. You must have obtained it at the 2010 HEAS event from my pal and HEAS regular member, T.R. Leary.

Tim Raney and I hazarded the walk across the horse pasture to the creek where much of the mine waste gets washed down to and panned out several pounds of this special thorium rich sand.

We call it "horse bite farm" because the horses think you are coming to feed them and gallop over. When ingored they tend to bite you. Tim got bit, but I did not.

As you decend down into the creek bed on a slow sloped hill, the GM counters went up when we were there due to stagnant air allowing the fast decaying Thoron gas to build up radpidly to equilibrium. Thoron is the original name given to thorium's radon emissions.

The black bits are ferritic iron and red garnets abound in this stuff. Both are attracted by NdFeB magnets and can be separated out using this technique. Only the orange-yellow and brownish granules are monazite and appear not to be attracted to super magnets.

To be expected, there are Uranium and Thorium series Daughters crawling all through that spectrum This is why Monazite sand will load up a gamma spec with lines. Unfortunately, using a NaI:Tl crystal many of those lines merge that are cleanly split using your plus ultra setup.
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.

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Steven Sesselmann
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Re: Identify the isotopes

Post by Steven Sesselmann » Sun Nov 21, 2010 9:25 am

Jon,

I tried to identify some of the isotopes in your spectrum, hopefully I got some of the right.

Looks like you bag of sand has a lot more stuff in it than meets the eye..

Steven
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Re: Identify the isotopes

Post by Jon Rosenstiel » Tue Nov 23, 2010 5:13 pm

Hi Steven,

Ok, I finally “graded your paper”, looks like you got about half of them right, pretty much on par with my first efforts into gamma spectrometry. (I’m attempting to keep up with the times and am trying to use spectrometry in place of spectroscopy). As previously mentioned, there are a few peaks that will make your head hurt. Two that I struggled with for longer than I care to admit are the Tl-208 (2615 keV) single and double escape peaks at 2104 and 1593 keV respectively.

And I should point out that in certain parts of the spectrum (mainly in the higher energy portion) my energy calibration is not as good as I initially thought. Bi-214 @ 2204.2 keV is one example that I ran across.

Richard, being from the area, hit the nail on the head; this is monazite sand containing both Uranium and Thorium series daughters. (Richard, the sand was a gift from a mutual friend of Bill Kolb and me).

Jon Rosenstiel
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Re: Identify the isotopes

Post by Starfire » Tue Nov 23, 2010 9:30 pm

nice one Jon - I am fascinated by the fact that particular isotopes always produce given energy of a particular strength - and wonder why?

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Steven Sesselmann
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Re: Identify the isotopes

Post by Steven Sesselmann » Tue Nov 23, 2010 10:24 pm

John,

My opinion FWIW.

It's the rungs on the ladder to the future..

The proton is on it's way down the potential energy ladder, to meet it's antiparticle, the electron.

Just like the anchor in a mechanical clock only allows the escape wheel to move one step at the time, so too, the atoms may only move by certain allowed steps.

What we are attempting to do with fusion, is to fiddle with the anchor, and make the escape wheel jump several steps in one go, and as we know it can be dangerous, if the wheel is allowed to spin freely. It's what we call a runaway reaction, literally the equivalent of pulling the anchor off a fully wound clock. The future will come real quick!

This is part of a new theory I am working on, where the electron and the proton are a particle pair, and we "the observers" are at the same potential as the proton, while the electron is at a potential of -938 Mev !

Imagine the H atom as an extremely deep fusor, with the grid sitting at -938 Mev, the grid is strongly attracted to the shell and the shell to the grid, but the two can not easily meet, as the potential energy difference is too large (same reason why the moon doesn't fall down), they end up circling each other instead.

However, certain dance steps are allowed....

The first rung is the conversion of H to D, which allows the p and n to loose a little bit of potential, then there is D to He3, and so on...

Were it not for these nuclear reactions, time would actually stand still. The end of all time is when the proton and the electron eventually meet at ground potential......, 939 Mev from now.

Can we measure time in electron volts ?

Steven

PS: It's fortunate that I don't rely on funding
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Re: Identify the isotopes

Post by Starfire » Wed Nov 24, 2010 1:09 am

Steven

Still does not explain why particular isotopes emit with characteristic energy - isotopes from the same element emit at different energy levels.

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Steven Sesselmann
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Re: Identify the isotopes

Post by Steven Sesselmann » Wed Nov 24, 2010 4:47 am

Jon,

Fascinating, the little K40 peak at 1460...., must be from you sitting next to the experiment

Steven
http://www.gammaspectacular.com - Gamma Spectrometry Systems
https://www.researchgate.net/profile/Steven_Sesselmann - Various papers and patents on RG

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