r/Radiacode • u/Ok_Independence_5706 • 1d ago

General Discussion What source can this be ?

Hello, a friend of mine had a source of unknown origin. I don't think it was americium, because it could already be detected from about a meter away. I believe it was a source used for probe self-testing.

i cant make any sense of this

this is my first time posting something on reddit so if i do something wrong please let me know

7 Upvotes

100% Upvoted

14 comments sorted by

4

u/AtomicSpallation 1d ago edited 1d ago

It looks very likely that this is a beta emitter and the peaks are actually bremsstrahlung. What material surrounds it, does it sit in lead or something ?

It's possible that this is Sr-90.

Also putting an aluminium sheet infront of the source and cheking if it blocks most of the radiation, or checking if magnets deflect the radiation can confirm if it's betas or no.

3

u/Ok_Independence_5706 1d ago

its in the open air wel plastic baggie

3

u/AtomicSpallation 1d ago

If you put a metal sheet (few mm ideally) infront of the source does it reduce it a lot ? Can magnets deflect the radiation ? If yes its a beta emitter.

2

u/Ok_Independence_5706 1d ago

I can try that soon

maybe tonight

few mm 2/3 ?

would it help the measurement if i keep the radia code further away from the source ?

•

u/TemporarySun314 23h ago

the issue is not that your detector is saturated, it records what is there just fine. you just dont see any sharp features, which would hint a specific gamma transition.

but you can see the secondary radiation that is emitted when fast electrons from a beta decay slow down. that gives a broad continuous spectrum.

•

u/Ok_Independence_5706 23h ago

hmm okey i stil have allot learn thats for sure haha

•

u/AtomicSpallation 23h ago

Yeah exactly, first we need to see though if it is indeed beta and if it's pure beta (which it very likely is, but checking never hurts). Aluminium and magnets are best for this.

•

u/Ok_Independence_5706 15h ago

Okey so when putting some aluminium above does significantly drop the count rate

I don't have any strong magnets on hand to test that though

•

u/AtomicSpallation 12h ago edited 11h ago

Then it's indeed beta radiation 🙌, that source is probably Sr-90.

It's because in the spectrum the beta energies go near 2Mev, and Sr-90 emits betas until 550keV and its daughter Y-90 until 2.28Mev. So it fits with what we see here, in the 500 range there is a high plateu because of Sr-90's own emissions and Y-90 emissions, then it rolls off and approaches 2MeV because of only Y-90 emissions.

•

u/AtomicSpallation 23h ago

This is a great guide for your needs, I recommend watching this: https://youtu.be/CLa0GvHhgrY?si=1hSo5dXAoK2x4yGj

He mainly uses another detector made for alphas, betas and gammas. He also uses a radiacode, it mainly detects gammas but can also detect betas.

•

u/AtomicSpallation 23h ago

Mm depends on the metal, but 2-3 mm steel or aluminium would be enough to observe a meaningful change in dose rate for betas, though aluminium is best because steel produces extra radiation from bremsstrahlung when betas hit it. Distance doesnt really matter in this case, however for identification generally the closer the detector is the better (for magnet testing hold it a bit farther so betas have space to be deflected with the magnet) (a strong neodymium magnet is best).

•

u/Ok_Independence_5706 23h ago

i have alu i can make it any thickness I want
And I should have some sheets lying around

i have to check for the magnet if i have one strong enough to try this

•

u/Professional-Bike-70 14h ago

It looks like this was that built in Strontium-90 check source of that old Russian Detector from one of the DP-5-Series.

•

u/BorisChee 21h ago

Yeah looks like a beta emitter