Original scientific paper
Resonance effect in inner-shell nd →1s two-photon decay
Ksenofont Ilakovac
; Department of Physics, Faculty of Science, University of Zagreb P.O.Box 162, 41001 Zagreb, Croatia; Ruđer Bošković Institute, 41001 Zagreb, Croatia
Abstract
Emission of photon pairs by the two-photon decay process from silver and hafnium atoms with a vacancy in the K shell was investigated. Radioactive decay of 109Cd and 179Ta was used to generate the K-shell vacancy states in silver and hafnium atoms, respectively. The measuring system consisted of a pair of planar high-purity germanium detectors, a fast-slow coincidence system, and a 128x512x512 channel pulse-height analyzer. Two-dimensional spectra of numbers of events as functions of amplitudes of coincident pulses from the two detectors were analyzed. The results on the 3d → 1s two-photon decay show the resonance behaviour, seen as a gradual increase of the differential transition probability as the partition of energy among the two photons of the pair deviates from equal-energy partition (E1=E2=E0/2). The effect was predicted by the second-order perturbation theory of two-photon decay in which summation over intermediate states is carried out over occupied and unoccupied bound states, and over unbound states.
Keywords
Hrčak ID:
305569
URI
Publication date:
1.2.1992.
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