Determination of the β− branching ratio of 64Cu by mass spectrometric investigations of the decay products in neutron transmuted copper

Abstract The β − branching ratio of 64 Cu was determined by investigating the resulting decay products in copper doped by neutron transmutation. The numbers of 64 Zn and 64 Ni atoms were analyzed using isotope dilution analysis combined with thermal ionization mass spectrometry. A β − branching ratio of (38.06±0.30)% was obtained, which agrees with the study of Kawada (Appl. Radiat. Isot. 37 (1) (1986) 7) to a higher accuracy. However, our result differs from the value cited in the NUDAT database of (39.0±0.3)%.