Factoring in both the positional dependence of the effciency and the beta-decay
spectrum of the electrons, we obtain a detection effciency of (48 [+ or -] 6) % when photomultiplier tube (PMT) threshold levels are set to three or more photoelectrons (see Ref.
Neutron radiative beta-decay
has never been definitively observed.
In addition, the neutron polarization can also be determined by directly fitting a beta-decay
asymmetry that is proportional to the neutron polarization.
Radiocarbon dating by counting the electrons emitted during these so-called beta-decays
therefore requires a large sample and a long counting time to obtain enough detector counts for a precise age estimate.