Radiation Detection

Hello!

I got a sample of fukushima soil from Luuk and took a few spectra with different detectors.
it has very visible ¹³⁴Cs lines, but of course the ¹³⁷Cs is dominant, with above 30 cps!
Sadly ¹⁵²Eu and others are below my detection threshold.

Here's a spectrum with my LaBr3:Ce detector, showing more of the low energy peaks, including the very strong Ba x-rays Here's the same spectrum with my HPGe. It shows more of the higher energy peaks, but is blind to the x-rays: ¹³⁴Cs has two pairs of peaks very closely spaced together, only separated by ~5 keV.
Those lines are well divisible on the HPGe and give a nice look into the resolution. Thanks to its short half life of about 2 years the ¹³⁴Cs is decaying at a visible rate, Luuk made a report about this soil a few years back and the peaks are way stronger!
https://www.gammaspectacular.com/phpBB3 ... p?f=5&t=27

All in all it is a very nice sample, both in the visible and ionizing ranges of the electromagnetic spectrum, with some real historic value behind it! Best regards,
Lukas

Welcome to the club Lukas,
i couldn't identify the first Cs134 peak in my sample with my 2''x2'' NaI(Tl), I had to do it indirectly.

An HPGe solves a lot of problems, the result is really nice.

Massimo

Hello Massimo,

Thank you, now I'm finally one of the cool kids! ;-)
What do you mean by indirectly identifying the peak?

Lukas

Hi Lukas,
Great results with your new LaBr3 detector, it works just perfect!
But my hart opens when I see the HpGe spectra, brings me back to old days a long time ago
when I build and tested them for Harshaw.
Luuk

Hi Luuk,

I am really happy how the LaBr turned out!
It really is a good alternative to the HPGe and I'll safe a lot of money on LN2 in the future.
Don't worry, I'll still supply lots of HPGe spectra as I find more interesting samples ;-)

Lukas

GigaBecquerel wrote: ↑

30 Aug 2020, 17:11

Hello Massimo,

Thank you, now I'm finally one of the cool kids! ;-)
What do you mean by indirectly identifying the peak?

Lukas

I meant this https://www.gammaspectacular.com/phpBB3 ... ?f=5&t=517

Oh, I see!
That's a very interesting technique I have not thought about before.

I am aware that those are two very different things, but your "cutting out peaks" reminded me of this fun experiment:
http://www.nuclearphysicslab.com/npl/np ... incidence/