Quizlet for you

[Milos]

Hi guys,

Today I have a Quizlet for you, see the spectrum below, please. What we are looking at is pretty obvious, I think; however, the question is: what material is it?

A) Calibration source
B) Old vacuum tube
C) Vintage surge protector
D) Mushroom
E) Lichen
F) Burnout nuclear fuel speck from Chernobyl (size 0.2 mm)

So, what do you think? :-) ...

[Svilen]

Since it is a clean 137Cs spectrum with a prominent barium x-ray peak and no clearly visible additional fission-product lines, I would guess that it is a calibration source. However, the sample cannot be clearly determined from the spectrum alone :)

[Milos]

Good suggestion Svilen :-), then F) can be ruled out. Anyone else?

[Rob Tayloe]

The spectrum shown above looks pretty clean. My guess would be a calibration source also. In the link below are some spectra from some actual fuel "specks" collected outside the Chernobyl facility and some discussion about detection of Eu-154 and Am-241.

https://fusor.net/board/viewtopic.php?t=6272

Below is a link to a YouTube video of a gamma spectra from NaI of a "speck" of Chernobyl fuel found outside the facility.

https://www.youtube.com/watch?v=LRMDc6zeVWQ

[Milos]

OK, I will tell you the correct answer to the Quizlet, and you won't believe it. It is a single boletus mushroom with a dry weight of 37 g from Gävle, Sweden.

During our trip to the far north, we were driving back to our country near Gävle. I found out that this area was one of the most contaminated in Sweden by the Chernobyl disaster, so I decided to make a stop there and collect some soil and mushroom samples. The spectrum below compares this sample with mushrooms collected in the forest where I live in the Czech Republic. The dry weight of the mushrooms from our forest used for the measurement was actually twice as high (72 g), but still, the signal is order of magnitude weaker.

The conclusion is that consuming mushrooms from such heavily affected areas could pose a significant health risk, I think.

[Daniel]

Would there also be a radium peak at 186Kev?

[Svilen]

Impressive mushroom contamination, Milos. Nice find!
Daniel, if I don't get you wrong and you mean the peak visible on the yellow graph - this is from backscatter.

[Daniel]

Impressive mushroom contamination, Milos. Nice find!
Daniel, if I don't get you wrong and you mean the peak visible on the yellow graph - this is from backscatter.

Having a moment along with quite a bit of gin at the time, Yes the 180kev crompton peak / back scatter - would this be bigger due to the aluminium of detector and xrf effect as I understand it. here's my backscatter on Cs137 as detected.

teach me to drink Gin and reply

[Svilen]

The aluminium housing can contribute, since Compton scattering may occur in any surrounding material, but the lead shielding is generally the more important contributor to this effect.

[Daniel]

The aluminium housing can contribute, since Compton scattering may occur in any surrounding material, but the lead shielding is generally the more important contributor to this effect.

Svilen, yes and I think that was an issue with the Theremino identifier, unknowing or careless use ment that it didn't warn user.
I have refinned mine.

I'm not looking for any competition and am the first to admit I distrust my own findings, but this is a fantastic discussion.

thank you

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