National Institute of Standards and Technology (NIST) research reveals the photon spectrum of free neutron decay for the first time
"The team measured two aspects of neutron decay: the energy spectrum of the photons, and also its branching ratio, which can provide information on how frequently the decays were accompanied by photons above a specific energy. The results of this effort gave them a branching ratio measurement more than twice as accurate as the previous value, *and the first measurement of the energy spectrum.* "
Published 14 June 2016 © 2016 American Physical Society
This is interesting as we observed thermal neutrons in *GlowStick* 5.3 and others have reported them too.
The key graph in the paper "Energy spectrum deposited by photons from radiative neutron decay." is worth taking a look at - imagine what this would look like on a Log Lin basis - would it look a little like "signal"?
Read about "Free neutron decay" in wiki
"About one in 1000 of free neutrons decay with an additional emitted gamma ray thought of as due to a sort of "internal bremsstrahlung" that arises as the emitted beta particle interacts with the charge of the proton in an electromagnetic way"
From a summary
"Based on 22 million electron-proton events, the researchers report an average branching ratio of 3.35×10−3 for product photons with energies between 14.1 and 782 keV"
"A second detector array of large area avalanche photodiodes directly detected photons from 0.4 to 14 keV"
Could this in part explain the "signal" in GS 5.2?