Investigation of the Ar L23-MM Auger spectrum, emitted after 1s ionization, by means of e–ion and e–e coincidences

Abstract

Abstract The L 2 3 –MM Auger spectrum of argon observed after 1s ionization is a superposition of several complete L 2 3 –MM spectra which are emitted in the presence of additional vacancies being left by preceding transitions and acting as `spectators'. The spectrum is decomposed into these partial vacancy satellite spectra by measuring in coincidence the electron energy and the charge of the final ion. Moreover the sequential emission of certain partial spectra is demonstrated via electron–electron coincidence spectroscopy. The results of both the e–ion and the e–e coincidence experiment are in very good agreement with those of a published step-by-step calculation of the deexcitation cascade in single configuration average approximation. With the help of the known levels from the 2p 4 and 3p 2 configurations pairwise sequential individual 2p 4 →2p 5 3p 4 →2p 6 3p 2 transitions have been identified. The pertinent partial spectra are compared to relativistic calculations of transition energies and rates. Very good agreement is found, permitting the identification of the spectroscopically inferred intermediate 2p 5 3p 4 levels.