Disk source storage box

How to build the perfect shield for your measurements? Discuss it here!
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kotarak
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Location: Brookfield, CT, USA
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Disk source storage box

Post by kotarak » 23 Sep 2020, 02:56

Just a super-simple idea for storing Sealed Isotope Disk Sources, using small lead bricks.
I have a few of these Spectrum Techniques disks for calibration and really hated the acrylic boxes they are shipped with. These sources should be properly shielded.

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More DIY details at http://blog.kotarak.net/2020/09/lead-pi ... otope.html
Andrey E. Stoev
Brookfield, Connecticut, USA

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Sesselmann
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Re: Disk source storage box

Post by Sesselmann » 23 Sep 2020, 21:02

Andrey,

Nice box, maybe you also need another safety label "This box is heavy, bend your knees" :)

Steven

kotarak
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Re: Disk source storage box

Post by kotarak » 23 Sep 2020, 23:49

Hi Steven,
It is not too bad - it weights 5kg and puts 2cm of Lead all around the disks. The CPM rate drops from 2100 CPM when unshielded, measured with a Geiger Counter right on the box surface down to 550-600 CPM with the shield in place.
Your "carousel" type storage is much more elegant! I might get it printed to check it out.
It remined me a set of test sources I had about 35 years ago. It was made in USSR during the mid 60s for educational purposes.
The container was a stainless steel cylinder filled with solid lead and had 6 vertical holes, much like the cylinder of a revolver. In 5 of these holes there were 1cm diameter aluminum rods, anodized in different colors with the radioactive isotopes in a recess at the end of each rod. On the other side of each rod there was a threaded hole.
A rotating, transparent plastic disk with detents and with a single hole served as a cover. The 6th hole was containing a longer "dummy" aluminum rod with a thread on the end which was sticking out thru the hole of the plastic disk, locking the cover from rotating when inserted and threaded.
Basically, you had to unscrew the dummy rod out, then rotate the disk and align the hole with one of the sources - all color coded that you can see thru the transparent disk, then thread the dummy rod into the back of the source rod and pull it out of the container. Each source rod was long about 10 cm and when the "handle" rod was threaded on back it gave you over 20cm distance between your hand and the radioactive material on the other end.
It was extremely well made and had with very high quality materials considering that the set was made in USSR.
The isotopes were the usual suspects - Na-22, Cs-137, Co-60, Sr-90 but it also had Kr-85 in a small glass bubble.
Andrey E. Stoev
Brookfield, Connecticut, USA

James Luck
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Re: Disk source storage box

Post by James Luck » 11 Oct 2020, 13:58

Very cool box, might have to steal this idea.

Just a add on I would do is put a higher density foam between the lead and the lid to avoid shi**ing, if and when the box is moved.

^ edit for top side^
Avoid shifting.
Last edited by James Luck on 13 Oct 2020, 02:01, edited 1 time in total.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

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iRad
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Re: Disk source storage box

Post by iRad » 11 Oct 2020, 14:51

...
Last edited by iRad on 13 Oct 2020, 11:40, edited 2 times in total.

James Luck
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Re: Disk source storage box

Post by James Luck » 13 Oct 2020, 02:00

iRad wrote:
11 Oct 2020, 14:51
James... I think you mean "shifting"... :)
Yay I may have lacked some brain on the preview side of things, there.
I'm gonna go see about changing that.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

kotarak
Posts: 65
Joined: 07 May 2020, 05:46
Location: Brookfield, CT, USA
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Re: Disk source storage box

Post by kotarak » 13 Oct 2020, 11:14

James Luck wrote:
11 Oct 2020, 13:58
Very cool box, might have to steal this idea.

Just a add on I would do is put a higher density foam between the lead and the lid to avoid shi**ing, if and when the box is moved.

^ edit for top side^
Avoid shifting.
James, you can check my blog for build details - http://blog.kotarak.net/2020/09/lead-pi ... otope.html

The disks are 0.175" thick and you can adjust the gap using the 4 screw to the precise spacing needed. My disks leave ever so slight indentation on the foam - an indication that they are slightly pressed and there is no place to shift - i've been carrying the box and they dont shift at all.
The graphite mold to cast the bricks is from ebay - it was around $15
Andrey E. Stoev
Brookfield, Connecticut, USA

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