Gamma spectrometer Theremino or PRA

[pawel1010]

I've built gamma spectrometer with CdWO4 scintillator crystal connected to diode with unknown parameters. The crystal dimensions are 30x7x5 mm. The output signal are positive pulses with heights in range 0-2 volts amplitude and 150 µs width at the bottom. Here is example output pulse from my spectrometer:

I have a problem with parameters configuration in Theremino or PRA. I tried with Theremino cause it looks simpler, I set: Bins:x2, Samp. 384000, Audio gain: 3.0, in BaseLine test: Position: 50 µs, Size: 100 µs, Max slope(%): 20, Max noise(%): 20.

For radium-226 source I get a single peak like for americium-241 which is not great.

How to configure Theremino parameters to get normal, correct spectrum?

[GigaBecquerel]

Hello Pawel,

Welcome to the forum!
CdWO4 generally isn't great for spectroscopy, especially of it's that small, but you should get more than one peak.
Your signal looks fairly noisy, what's the mVpp on the baseline vs mean signal height?
Also, I recommend using BecqMoni, which gave me the best results from all audio MCAs.

Regards,
Lukas

[Sesselmann]

Pawel,

Welcome to the forum.

I would be happy to provide assistance with PRA as it is my preferred program.

Just a few housekeeping matters first. Please give yourself a quick introduction in the introductions forum and if you attach images to your posts please resize the images to a reasonable size jpg.

I notice your 10MB image is hosted on a different server, but it is slow to load and if it is ever removed from your server, this post will hang without an image.

Thanks..

Steven

[pawel1010]

Dear GigaBecquerel,

I created the new topic, because I consider electronics problem with my detector.

Here is the link to the topic, where is video of pulses with the mVpp statistics on the baseline: viewtopic.php?f=14&t=992