Reinvestigation of the α-activity of Conway granite

ADAMS et al.1,2 reported evidence for an unidentified 4.4 MeV α-activity in certain core sections taken from Conway granite in New Hampshire. A similar α-activity has also been reported by Cherdyntsev et al.3 and by Brukl et al.4 in different materials, but in neither case was it ever confirmed. We report here our reinvestigation of this phenomenon, and that we were unable to confirm the evidence of a 4.4 MeV α-activity in the Conway granite.