Gamma Spectrometry Forum

Pb210 decays to Bi210 by beta emission. I am thinking maybe this 15 keV line is a decay x-ray for this reaction. My x-ray tables for Bi shows characteristic X-rays in the L shell at 10.8, 10.7, 13.0, and 15.2 keV. I have only seen K shell decay x-rays, but maybe this is not energetic enough to produ...

Joseph, thanks again for another clear and detailed reply.

Joseph, I really appreciate your detailed reply. In my simple , and probably wrong, way of thinking the Compton plateau is bracketed by the Compton edge (energy of 180 degree recoil electron ) and the backscatter peak (energy of 180 degree scattered photon). I assume the values in between are from p...

If you want to observe the Compton minimum i would suggest an easy demonstration I found in an article by Dr. David Prutchi. I found it useful for understanding Compton interactions. It places a target outside the crystal to increase the number of scattered electrons that do not interact with the cr...

The distribution of the radioactive material in the mineral can make a difference. If it is on the surface, you can expect better resolution on the low energy end than you would with a dense, homogeneous material.

A bit off topic, the calculator below graphs recoil electron energy (Compton edge) and scattered photon energy (backscatter peak) based on incident photon angle and energy. You can play with it and see why Compton plateau features aren't seen below 250 keV, and why visible light (2-2.6 eV) and low e...

Marc,

In reference to your "D" peak, my RaDecay V3 program lists U235 photon emissions at both 105 and 109 keV. The probabilities are not very high, but maybe combined it might be responsible for that peak.

Sparky

I've been working with the preliminary data of my pancake CR detector to try and calculate a Cosmic Ray Flux that I could compare with what Dolleiser reported. I posted a description of the basic arrangement of my detector, and the data earlier. He reported a zenith angle flux and an equation (#6) t...

I have some preliminary data from my dual pancake secondary cosmic ray (muon) detector. The hardware worked very well. Using just the active area of the lower tube, I get a flux rate of .87 counts/(cm^2 min). I believe 1 counts/(cm^2 min) is a number I have seen as a usual average in literature. I a...

I count as one fascinated by Cosmic Rays. I enjoyed and learned from Dr. Dolleiser's paper. I have also tried to estimate the secondary CR flux with GM tubes, but my efforts look very childish in comparison. I built a "muon telescope" with a viewing window sized to overlap such that 0-180 ...