Info on some PMTs?

Scintillation crystals, PMTs, voltage dividers etc...
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Re: Info on some PMTs?

Post by brehwens » 17 May 2015, 07:53

Hi Neil!

I could test the R374HA using a VD I had for a ET Enterprises 9124B tube, which was wired the same, and I was pleased to see that it worked. I did not have any good NaI crystal to test it with, all I had was a thin (XRF-style) crystal with a thin end window but with a crack. I figured it would at least tell me if the PMT was a dud. I was surprised to see that despite the crack, the crystal actually performed quite well. Add to this, I don't really know how good the PMT actually is so there might be room for improvement with a better PMT/optimization.

I already have an XRF probe, so this crystal is on its way to Steven now, it will be interesting to see what it can do.

I incuded Am241 and Eu152 spectra for comparison. Note that the X-axis is not calibrated, I could not bother. My XRF probe appears to have better resolution, but then again it is not cracked. The end window of my XRF crystal is aluminum, but I am not sure what the end window of the cracked crystal is, it doesn't look precisely like aluminum, maybe it is beryllium. I also suspect the cracked crystal is thinner than the 6mm of my XRF crystal; look at how quickly the response disappears at the higher energies in the Eu152 spectrum.

The two larger 2" PMTs were dead, I tested them with the same crystal.
20150515_004605.jpg (1.5 MiB) Viewed 837 times
20150515_004517.jpg (3.34 MiB) Viewed 837 times
Eu152 crap probe.png
Eu152 crap probe.png (228.29 KiB) Viewed 837 times
Eu 152 ScionixXRF.png
Eu 152 ScionixXRF.png (198.63 KiB) Viewed 837 times
Am241 Scionix XRF.png
Am241 Scionix XRF.png (199.24 KiB) Viewed 837 times
Am241 test probe.jpg
Am241 test probe.jpg (103.93 KiB) Viewed 837 times
Karl Brehwens
Eskilstuna, Sweden.

Setup: 5 cm lead castle, 2mm copper lining. Gamma Spectacular Pro 2002, Sound Blaster Live! 5.1,
Primary detector: Scionix refurbished 2x2" NaI(Tl) well detector, 7.5% @ 662 keV

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