Shield idea

How to build the perfect shield for your measurements? Discuss it here!
luuk
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Re: Shield idea

Post by luuk » 31 Jul 2017, 00:36

Hi Jonathan,
You have to keep in mind that NaI(Tl) is none linear below 100KeV so Am-241 is not good for callibration.
You could use the K-40 peak to callibrate you can find it in all around but you can also buy low sodium salt
that contains a lot of it.

Luuk,

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sgt_bear
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Re: Shield idea

Post by sgt_bear » 31 Jul 2017, 02:35

Hi Luuk,

Yes i know, but Am-241 and Lu-196 were the only items i have where i exactly know their energies. I will check for low sodium salt in store soon. I also think that it has to do with the theremino "energey equalizer"... so i guess for theremino you need a multiple engery source like Eu-152
- Jonathan from Switzerland

luuk
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Re: Shield idea

Post by luuk » 31 Jul 2017, 04:31

Hi Jonathan,
I still have some Fukushima (Cs-137+Cs-134soil maybe you would be interested in some, mail me oflist.
Luuk

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Peter-1
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Re: Shield idea

Post by Peter-1 » 31 Jul 2017, 20:13

Hello Luuk,
I am very interested in a small sample. Do you think it is possible. I am in germany.
Kind regards
Peter

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Steven Sesselmann
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Re: Shield idea

Post by Steven Sesselmann » 31 Jul 2017, 21:59

Jonathan,

That peak looks awfully sharp for K40, are you using some kind of convolution.

Normally the K40 peak is more of a hump.

Steven
Steven Sesselmann | Sydney | Australia | gammaspectacular.com | groundpotential.org | rephopper.com | beejewel.com.au |

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sgt_bear
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Re: Shield idea

Post by sgt_bear » 01 Aug 2017, 04:48

I tried with the PRA Software today, and get the same peak, so its not a problem of theremino.

The problem must be either on the detector it self or the electronics. I will look for K-40 in the store next week, so i can try to detect K-40
- Jonathan from Switzerland

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Steven Sesselmann
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Re: Shield idea

Post by Steven Sesselmann » 01 Aug 2017, 12:57

Jonathan,

Here are a few examples of K40

http://www.gammaspectacular.com/gamma_s ... a-spectrum

As you can see the NaI detector produces a fairly wide peak.

Steven
Steven Sesselmann | Sydney | Australia | gammaspectacular.com | groundpotential.org | rephopper.com | beejewel.com.au |

cicastol
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Re: Shield idea

Post by cicastol » 01 Aug 2017, 19:29

sgt_bear wrote:Hello!

CUT
So i decided to go with the lead balls (0.8mm, very fine), the company who sold it (Scherrer Metec) told me the weight of one litre would be 7kg, so its about factor 0.79 in dense, compared to solid lead.
CUT
Regards
Jonathan
Hi Jonathan,
your's math doesn't sound right to me, weight of 1 Liter of solid Lead is 11,34Kg, if 1 liter of your's Lead shots pellets weight 7Kg the "fill factor" should be a much lower 0,62. :-)

Good job so far!
Ciro

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sgt_bear
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Re: Shield idea

Post by sgt_bear » 02 Aug 2017, 23:34

cicastol wrote: Hi Jonathan,
your's math doesn't sound right to me, weight of 1 Liter of solid Lead is 11,34Kg, if 1 liter of your's Lead shots pellets weight 7Kg the "fill factor" should be a much lower 0,62. :-)

Yes you are correct, i was using a wrong formula in my calculator...

Its now ajusted, and 30mm's of balls would equal only 18.52mm of solid lead.
- Jonathan from Switzerland

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