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More experimentation today, this time getting the side well to work properly.
I'd been told by an ex harshaw employee via email that the well is thin enough to accept/pass through of 15KeV. Sure enough, he was right.
Note how sharp the spectrum looks now..
Something worth noting here, the 32KeV X-ray
decay channel is by β− (that is the conversion of a neutron into a proton with the release of an electron and a electron anti-neutrino) which makes the daughter Ba-137 in an excited state called Ba-137m - this returns to ground state by the
32KeV x-ray emission. The 662KeV is gamma.
A GM detector has a hard time picking up on this source as most of the 662KeV Gammas pass straight through the detector. At ~0.3uCi the tube registers on average 1500CPM (electrodes at the centre) and if placed with the electrode tips facing the centre of the tube, 6500-7000CPM is observed briefly.
However, a much different story occurs when we put the tube into the scintillation detector well. A count rate of 125,000 CPM is obtained. The attenuation in NaI/Tl is greater than a GM tube. Higher Atomic mass.
I'd been told by an ex harshaw employee via email that the well is thin enough to accept/pass through of 15KeV. Sure enough, he was right.
Note how sharp the spectrum looks now..
Something worth noting here, the 32KeV X-ray
decay channel is by β− (that is the conversion of a neutron into a proton with the release of an electron and a electron anti-neutrino) which makes the daughter Ba-137 in an excited state called Ba-137m - this returns to ground state by the
32KeV x-ray emission. The 662KeV is gamma.
A GM detector has a hard time picking up on this source as most of the 662KeV Gammas pass straight through the detector. At ~0.3uCi the tube registers on average 1500CPM (electrodes at the centre) and if placed with the electrode tips facing the centre of the tube, 6500-7000CPM is observed briefly.
However, a much different story occurs when we put the tube into the scintillation detector well. A count rate of 125,000 CPM is obtained. The attenuation in NaI/Tl is greater than a GM tube. Higher Atomic mass.
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