Radiative K Capture

Accompanying K capture, as in β-activity, there is a weak continuous high energy gamma-ray spectrum. The major contribution to the effect is from magnetic radiative capture of a K electron. For an allowed transition using Fermi or Gamow-Teller coupling, the number of gamma-quanta per K electron captured is (α12π)(Wmc²)², where W is the available energy. For other couplings and forbidden transitions, the effect is of the same order of magnitude.