The end-point energy of the superallowed Fermi decay of38mK

Abstract
The threshold for the 38Ar(p,n)38K reaction has been measured relative to the thresholds for 10B(p,n)10C and 14N(p,n)14O. The value deduced for the 38mK beta endpoint energy, 5020.71+or-0.85 keV, enhances the evidence for a trend of ft with Z.