Gamma Spectrometry Forum

Steven NIM standard is from 1964, people didn't have computers with sound cards back in the day. I'm not saying that this is not working, I'm saying that people have done this already and one can learn from their experiences. Maybe I misunderstood what you mean by E_compton. Normally, E_compton is t...

Steven The Compton continuum ranges from 0 to E_compton, where E_compton depends on the incident gamma energy ( the formula is here https://en.wikipedia.org/wiki/Compton_edge ) and can be larger than m_electron*c^2. I think your suggested method is too simple: By scaling the photopeak such that the ...

Steven I think that idea works in principle, and is sometimes applied in gamma-spectroscopy. But it is not easy as I'll describe below. First of all, the angular distribution of photons after a single Compton scattering event can be theoretically calculated with the Klein-Nishina formula https://en....

I agree that betas explain the observed behavior. Looking at the decay radiation of 137Cs (https://www.nndc.bnl.gov/nudat3/decaysearchdirect.jsp?nuc=137Cs&unc=NDS), there are betas with even higher energy than 510 keV emitted. There is a 5% chance for a decay from 137Csdirectly into the ground s...

There are online calculators for the stopping power of electrons in various materials. For example this one https://physics.nist.gov/PhysRefData/Star/Text/ESTAR.html It says that 500 keV electrons have a range of 0.1667 g/cm^2 in Polyethylene. The density of Polyethylene is 0.94 g/cm^3. The range in...

Thanks Peter and Stephen for the information I didn't know about glass scintillation. I did a ltspice simulation of my positive divider circuit an found out that the reason for the noise that I could see was probably the high input impedance of the oscilloscope I used to look at the pulses. I think ...

Hi all, Since recently I was only working with negative HV supply for the PMTs of scintillation detectors. Reason: lack of a positive HV source. I do have detectors with "housing at cathode potential, use positive HV only" written on them... and I did operate them with my negative supply a...

So the simple conclusion is: that it will not be possible without the use of a special high resolution crystal to really separate these two peaks, so just a small bump on the edge is all you can detect. Luuk Yeah, after a 18 hours measurement + roughly as much for background I know by now that that...

Hello everybody, week-end is ending and I wanted to show my progress in improving my dynamic time over threshold device that I've shown previously: https://www.gammaspectacular.com/phpBB3/viewtopic.php?f=15&t=366#p1735 Some points that I'm trying to improve: The old device needs a third party FP...

Hi Steven, the setup looks quite nice! I think such a setup could also be use to measure gamma-gamm angular correlations (the change in the coincidence count rate of two detectors, if the angle detector1-source-detector2 is changed). One can see two GS-USB-PRO in the picture, and I'm wondering how w...