I first reported success with the neutron activation of Cobalt-59 (result was 10.5-minute Co-60m) in these forums back in 2012. viewtopic.php?f=13&t=6300&p=34744&hilit=cobalt#p34744
In that post I had also written about a failed attempt to activate 166 grams of cobalt metal powder in an effort to turn up 5.3-year Co-60.
So now, years later, the Co-60 nut has finally been cracked. On three separate occasions over the past 5-years I’ve managed to neutron activate 822-grams of cobalt metal powder, the result being 5.3-year cobalt-60. The first two successes (2015 and 2018) were done with my spherical fusor, the final (Nov - Dec of 2020) with the cube fusor.
822-grams of cobalt metal powder (obtained from an eBay seller) was divided and poured into two 6-mil poly baggies. (Interestingly, as received, the cobalt powder already had some Co-60 activity) For activation with my spherical fusor the two baggies were stuffed into a Marinelli beaker, the beaker placed in a bucket of water which in turn rested on top of a 1.25” thick UHMW moderator. For activation with my cube fusor each baggie was sandwiched between blocks of HDPE moderator positioned at each end on axis with the cube’s beam lines. For counting on the gamma spectrometer both baggies were stuffed in the aforementioned Marinelli.
Cobalt powder activation timeline:
First activation (Spherical fusor): July of 2015. Five separate activations for a total time of five-hours. Average TIER of 4.8E+06 n/s. Before/after activity increase of ~48 counts/hour.
Second activation (Spherical fusor): February of 2018. Three separate activations for a total time of 3.25-hours. Average TIER of 5.6E+06 n/s. Before/after activity increase of ~46 counts/hour.
Third activation (Cube fusor): Nov/Dec of 2020. Four separate activations for a total time of 2.8-hours. Average TIER of 4.5E+06 n/s. Before/after activity increase of ~64 counts/hour.
Note that even though the cube fusor had the lowest average TIER and shortest activation time it’s before/after activity increase of 63 counts/hour is quite a bit higher than that of the spherical fusor. This can, I think, be mainly be attributed to the cube’s better activation geometry. (Center of my spherical fusor to its neutron oven’s lower shelf is 10.7 cm. For the cube it’s around 6 cm)
Jon Rosenstiel
Neutron Activation of Cobalt-59 Yields 5.3-year Co-60
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Re: Neutron Activation of Cobalt-59 Yields 5.3-year Co-60
Very cool Jon. You and Joe Gayo are probably the only two people on this site that can currently generate enough neutrons to do this activation in a reasonable amount of time.
Your detector setup for generating spectra is without doubt vastly superior to what anyone else here has.
Joe.
Your detector setup for generating spectra is without doubt vastly superior to what anyone else here has.
Joe.
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Re: Neutron Activation of Cobalt-59 Yields 5.3-year Co-60
Incredible work Jon! Co60 is a big stretch. You are at the outer limits while I am here spending hundreds so that I do the easiest activation on earth. "the Fermi favorite".
I notice the castle. How long have you had it! Where did you get it! We had a bigger one just like it thrown out at our scrap yard `1.6 tons and over a meter in diameter with several layers of copper and cadmium. The mass and the lead alone kept me from any real interest. The yard charges by the current spot for lead. (just around $1.00/lb) Alas, I left it to its fate. It is now gone.
Richard Hull
I notice the castle. How long have you had it! Where did you get it! We had a bigger one just like it thrown out at our scrap yard `1.6 tons and over a meter in diameter with several layers of copper and cadmium. The mass and the lead alone kept me from any real interest. The yard charges by the current spot for lead. (just around $1.00/lb) Alas, I left it to its fate. It is now gone.
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
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
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Re: Neutron Activation of Cobalt-59 Yields 5.3-year Co-60
Joe,
Thanks. For some odd reason I'm driven to find out what makes things tick... and to that end I've collected or constructed the necessary tools to make that happen. From what I can tell I'm not the only one here that has this problem.
JonR
Thanks. For some odd reason I'm driven to find out what makes things tick... and to that end I've collected or constructed the necessary tools to make that happen. From what I can tell I'm not the only one here that has this problem.
JonR
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Re: Neutron Activation of Cobalt-59 Yields 5.3-year Co-60
Richard,
I've had the lead castle for several years. I'm guessing it may have come from Los Alamos as I got it from an outfit in Santa Fe, NM. (Don't remember the outfit's name though) Tag on the back says; Applied Physical Technology (APT) Atlanta, GA. Weighs 2450 pounds... about the same as the BMW 2002 had back in the 70's.
JonR
I've had the lead castle for several years. I'm guessing it may have come from Los Alamos as I got it from an outfit in Santa Fe, NM. (Don't remember the outfit's name though) Tag on the back says; Applied Physical Technology (APT) Atlanta, GA. Weighs 2450 pounds... about the same as the BMW 2002 had back in the 70's.
JonR