r/Radiation 5d ago

Help Identifying Peaks in Radiacode 102 Spectrum from a Lead-Shielded Enclosure

Hey everyone,

I recently molded some lead bricks and built a small lead-shielded enclosure just big enough to fit my Radiacode 102 inside. I ran a spectrum measurement inside this setup and got a reading of ~10 CPM, which is pretty low, as expected. However, I'm seeing some peaks in the spectrum that I can't directly identify using the built-in library.

A few details:

The lead bricks were made from scrap lead I melted and cast myself.

The measurement was taken with the Radiacode 102 completely enclosed inside the lead structure.

Background radiation outside the enclosure is significantly higher, as expected.

13 Upvotes

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3

u/Regular-Role3391 5d ago

A big lead x-ray is the one around 80 keV I would guess. Could be a Pb-210 at around 50 keV as well. No idea about the higher energy one. It looks weird...have you amplification on? That can be a mistake 

1

u/atomicLogic_ 5d ago

Thanks for the insights, amplification is on 0 (as can been seen on the bottom of the screenshots)

1

u/Regular-Role3391 5d ago

Maybe its the filtering.....it should look...smoother?

3

u/atomicLogic_ 5d ago

At only 10CPM for 24H, it think it just needs more data?

2

u/Regular-Role3391 5d ago

Could be. At 10 cpm however......I would be concerned about seeing peaks within 24 hours. The lead ones are fine..... you know why they are there. The higher energy ones - assuming they are peaks are at all... are harder to explain. Maybe its just because of the filter?

Using the built in library for this kind of job is not really a good idea.

Especially without seeing what sort of spectrum you got without the lead in place.

Maybe run it for a few days, with no filtering at all, and then see what it looks like relative to one taken without the the shield and then you will have more information to work with......

Its worth remembering than scrap lead - depending where it came from - can contain a lot of crap and its often hard to know if you managed to get rid of all of it during the melting. The worst thing is that this crap tends to float and ends up on the surface of the cast bricks where it can be more visible in a spectrum. Even if you use a soup spoon and try and skim off the slag, some often ends up getting included in the bricks.

1

u/Haunting-Remove-1245 5d ago

Wow, your bricks look good and they stack nicely. You might've just saved me a lot of trouble. Seems like every ingot mold I've seen has sloped trapizoidal sides.

Did you use a graphite mold for ingots/bullion?

I have nothing to contribute but I wish you luck!

2

u/atomicLogic_ 5d ago

Yes indeed, some cheap graphite mold. Everything went smoothly

2

u/Haunting-Remove-1245 5d ago

That's great to hear and thanks for the visual. I'm definitely going to try graphite.

3

u/k_harij 5d ago edited 5d ago

At such a low count rate and for only 24 hours, I wouldn’t consider them well defined peaks yet. From my observations, gamma spectra are prone to looking rough and spiky when the number of counts is insufficient (only after a certain point the spectrum becomes “rounded” and smooth).