that were independent of the frequency of the incident photon suggested a mechanism for electron ionization that was caused from an internal conversion of energy from a radiationless transition. Further investigation, and theoretical work using elementary quantum mechanics and transition rate/transition probability calculations, showed that the effect was a radiationless effect more than an internal conversion effect. See also Auger therapy Charge carrier generation and recombination Characteristic X-ray Coster–Kronig transition Electron capture Radiative Auger effect References Atomic physics Foundational quantum physics Electron spectroscopy