when a nucleus of the copper isotope 64cu emits a positron it becomes
Copper-64 64Cu has a half-life of 12.701 ± 0.002 hours and decays by 17.86 (± 0.14)% by positron emission to 64Ni, 39.0 (± 0.3)% by beta decay to 64Zn, 43.075 (± 0.500)% by electron capture to 64Ni, and 0.475 (± 0.010)% gamma radiation/internal conversion. These emissions are 0.5787 (± 0.0009) and 0.6531 (± 0.0002) MeV for beta minus and positron respectively and 1.34577 (± 0.00016) MeV for gamma.[1]