DECAY OF HIGHLY EXCITED ATOM STATES IN THEIR ACTUAL SURROUNDINGS

Highly excited atom states carrying single or multiple vacancies in in ner and/or outer shells still represent a subject of great relevance f or both basic and applied research. Particularly, for inferring ioniza tion cross sections or elemental abundances from measured x-ray line i ntensities, precise knowledge of the x-ray fluorescence yields appears indispensable. Bawd on previous exemplifying multi-centre calculation s, the present paper attempts to include environmental and multiple-va cancy aspects in a dense approximate single-centre model for third-row main-group emitter atoms, which can readily deliver realistic transfe r probabilities and fluorescence yields as parameters describing the c ascading de-excitation of multiply ionized atoms in their chemical sur roundings. In particular, the results of the present analysis justify in retrospect the tentative use of single-hole standard fluorescence y ields in recent experimental work.