Excellent report, Carl. Looks like you've definitely got something there, hope you can flush out the culprit (s) via gamma spec.
Pa-234m may be the bug in the ointment. I took a look at an HPGe gamma spec I ran on a chunk of DU; Pa-234m has quite a few gammas in the 1.8 ~ 1.9 MeV area. One of the stronger ones is at 1.832 MeV, very close to Rb-88’s 1.836 MeV gamma.
Jon Rosenstiel |