RESUMEN
A novel approach for isomer depletion in ion-atom collisions is proposed and considered theoretically. Analyses are performed for the depletion of the ^{93m}Mo isomer for which an unexpectedly large probability was measured in the beam-based experiment of Chiara et al. [Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483]. The subsequent attempt at a theoretical description based on state-of-the-art atomic theory did not reproduce the experimental result [Wu et al., Phys. Rev. Lett. 122, 212501 (2019)PRLTAO0031-900710.1103/PhysRevLett.122.212501] and showed a dramatic disagreement with the experiment (by many orders of magnitude). This conflict calls for further research on the nature of isomer depletion mechanisms occurring in atomic processes. Here, we propose to consider the ^{93m}Mo isomer depletion as the nuclear excitation by electron capture in resonant transfer process taking into account the momentum distribution of the target electrons. Although our results only slightly shift the upper theoretical limit for the total ^{93m}Mo isomer depletion probability toward the experimental value, they show the importance of considering the Compton profile in the theoretical description, in particular for the L shell, for which the depletion probability increases by many orders of magnitude.
RESUMEN
Close to an x-ray filter's K-edge the transmission depends strongly on the photon energy. For a few atom pairs, the K-edge of one is only a few tens of eV higher than a K-line energy of another, so that a small change in the line's energy becomes a measurable change in intensity behind such a matching filter. Lutetium's K-edge is ≃27 eV above iridium's Kα(2) line, ≃63.287 keV for cold Ir. A Lu filter reduces this line's intensity by ≃10 % when it is emitted by a plasma, indicating an ionization shift Δε≃10±1 eV.
RESUMEN
We propose a novel approach for the theoretical analysis of the photoinduced high-resolution K(h)α(1,2) x-ray hypersatellite spectra, which allows us to obtain reliable values of lifetimes of the doubly K-shell ionized states and fundamental information about the relative role of K-shell double photoionization (DPI) mechanisms. It is demonstrated for the first time that the K(h)α(1,2) hypersatellite natural line broadening observed for selected metal atoms with 20 ≤ Z ≤ 30 can be well reproduced quantitatively by taking into account the influences of the open-shell valence configuration (adopted from predictions of the band-structure method) and the outer-shell ionization and excitation following the DPI process.
