Strontium beta spectrum

[lodovico]

Hello to everybody,
here below there is the spectrum of a beta source of Strontium 90 0,1uCi acquired with a NaI(Tl) 25mmx25mm scintillation crystal.
There are 3 peaks, maybe the first two are due to the two energies of beta decay of Strontium : 0,5MeV and 2,28MeV but what is the third at higher energy ? Maybe it can due to bremsstrahlung radiation caused by the electrons that are slowed down inside the NaI crystal ? Could this be an explanation in your opinion ?
Thank you
Lodovico

SPECTRUM_stronzio_3.png (36.99 KiB) Viewed 6746 times

[Sesselmann]

Lodovico,

I can't be of much help, but I googled Sr90 spectrum and found a NaI spectrum showing similar peaks on the left side, but without the peak at 800 keV

http://www.ld-didactic.de/software/5242 ... x/Sr90.htm

If you can read some German, this is actually not a bad resource.

http://www.ld-didactic.de/software/5242 ... ources.htm

Steven

[lodovico]

Thank you,
I found that the peaks on the left side are X-rays from Iodine and thallium, XRF excited by beta electrons.
There is the continuum due to the beta electrons but I do not know how to explain the peak on the right side, maybe it is a sort of artifact.
Lodovico

[Sesselmann]

Might just be the limit of your sound card. If you repeat this using PRA, you may see the peak at 100 arb.u.

One tends to get a pile up at the sound card limit, because pulses of higher energy fall into the last bin.

Steven