RadiativeKCapture

Accompanying $K$ capture, as in $\beta$-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 $\left(\frac{\alpha }{12\pi }\right){\left(\frac{W}{m{c}^2}\right)}^2$, where $W$ is the available energy. For other couplings and forbidden transitions, the effect is of the same order of magnitude.