Gamma Spectrometry Forum

Version 15 with the "res%" display is a real plus and this starts to give results very quickly. FYI, when auto selecting the ROI the keyboard shortcut "D" seems best (D = double or very wide ROI) as this selects the whole of the ROI and thus gives a result more consistent with th...

Steven Yes I was concerned about the radon build up and couldn't find a simple method to vent to outside. As an alternative I have put samples in old plastic pill containers with tight fitting lids that I retrieve and open outside when I want a sample. Do you think this is OK? Initially I tested som...

Steven Probably not as it came from the US. There are no markings on it and it did not have any original packaging it was simply sold as CsI(Na) when I felt the weight it sort of confirmed it was. I put it temporarily onto a PMT and within an hour of receiving it found it has such a good resolution....

Thanks for the feedback. Yes the housings make the difference, some of those odd sized ones I made are only PVC pipe with a disc cut out of an end cap and glued into the bottom, then an end cap is pushed on the other end and the whole lot spray painted with a can of blue paint that turned out to be ...

Tim The photocathode is on the face of the PMT so from there onwards there is an electron beam so I guess you need the Mu metal shield to cover the full length of the tube as opposed to only the dynode assembly within the 2" straight section? Maybe someone can comment on the effectiveness of on...

Hello all. For general interest, this post is about a 2"x2" unbranded scintillator I found for a good price a while back and it returned surprisingly good resolution. I built a detector using a Philips XP5212 PMT (8.8% 57Co) in much the same construction as my previous post on Scionix... i...

I recently came up with a simple idea for a low cost underground store for small quantities of low level samples. It uses plumbing pipe and fittings to give a 150mm diameter waterproof underground storage vault. This seems to do the job, have a look at the attached pictures to make sense of the foll...

Hello everyone, I'd like to share this build from last August. Intro: Prior builds. I built my first detector last April (2"x2" NaI(Tl)) which had 9% resolution. I experimented with several PMT's, various divider resistances (18 to 60+M) & tried split signal. The detector functioned we...

Vit Thanks for that observation, I wish I had used a copper pipe instead of steel in the lead shield construction. Anyway I bought a copper sheet (0.016" thick) a few weeks back that I want to see if I can fit around the detector and line the sample chamber to see if even a thin copper sheet ca...

Steven Yes it's very compact. In reply to your questions, from the user manual the energy range claimed is 50keV to 6MeV?? There is no reference to efficiency across the range. The accuracy is given as below 20% or 0.15uSv/h. The scintillator is CsI(Tl) with 2000CPM/uSv/h for 137Cs. You mentioned th...