Naslov
Two-photon decay in silver and hafnium atoms

Autori
Ilakovac, Ksenofont ; Horvat, Vladimir ; Krečak, Zvonimir ; Jerbić-Zorc, Gorjana ; Ilakovac, Neva ; Bokulić, Tomislav

Izvornik
Physical Review A (1050-2947) 46 (1992), 1; 132-141

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
two-photon decay; transition probabilities

Sažetak
The decay of silver and hafnium atoms with a vacancy in the K shell by the emission of photon pairs which continuously share the transition energy was studied. Radioactive decay of 109Cd and of 179Ta was used to generate K-shell vacancy states in silver and hafnium atoms, respectively. A pair of germanium detectors in a 180° geometry and a fast-slow coincidence system with a (128×512×512)-channel three-parameter pulse-height analyzer were used in the measurements. Two-dimensional spectra of numbers of events as functions of amplitudes of coincident pulses from the two detectors were analyzed. Surface fitting of two-dimensional spectra and curve fitting of sum spectra were applied to deduce the number of events. The differential transition probabilities of 2s→ 1s, 3s→ 1s, 3d→ 1s, and 4sd→ 1s two-photon decay per decay of a K-shell vacancy have been determined. For silver they are compared with the results of relativistic self-consistent-field calculations of Mu and Crasemann [Phys. Rev. A 38, 4585 (1988)] and of Tong, Li, Kissel, and Pratt [Phys. Rev. A 42, 1442 (1990)]. The results for silver and hafnium are compared with the results of nonrelativistic calculations for hydrogenic silver and hafnium ions. The 3d→ 1s two-photon decays show the resonance effect, in accordance with the theoretical predictions.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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