RESUMEN
We report on new measurements of m-fold photodetachment (m=2-5) of carbon anions via K-shell excitation and ionization. The experiments were carried out employing the photon-ion merged-beams technique at a synchrotron light source. While previous measurements were restricted to double detachment (m=2) and to just the lowest-energy K-shell resonance at about 282 eV, our absolute experimental m-fold detachment cross sections at photon energies of up to 1000 eV exhibit a wealth of new thresholds and resonances. We tentatively identify these features with the aid of detailed atomic-structure calculations. In particular, we find unambiguous evidence for fivefold detachment via double K-hole production.
RESUMEN
Double and triple detachment of the F^{-}(1s^{2}2s^{2}2p^{6}) negative ion by a single photon have been investigated in the photon energy range 660 to 1000 eV. The experimental data provide unambiguous evidence for the dominant role of direct photodouble detachment with a subsequent single-Auger process in the reaction channel leading to F^{2+} product ions. Absolute cross sections were determined for the direct removal of a (1s+2p) pair of electrons from F^{-} by the absorption of a single photon.
RESUMEN
Single, double, and triple ionization of C(1+) ions by single photons is investigated in the energy range of 286-326 eV, i.e., in the range from the lowest-energy K-vacancy resonances to well beyond the K-shell ionization threshold. Clear signatures of C(1+)(1s2s(2)2p(2) (2)D,(2)P) resonances are found in the triple-ionization channel. The only possible mechanism producing C(4+)(1s(2)) via these resonances is direct triple-Auger decay, i.e., a four-electron process with simultaneous emission of three electrons.
RESUMEN
The principle of microscopic time reversal of physical processes, detailed balance, is widely used and depended upon in the theoretical community as a connection between photorecombination (PR) and photoionization (PI). This paper reports on a novel use of detailed balance and the comparison of experimental results obtained by two very distinct techniques to determine both the metastable fraction of an ion beam and partial Sc3+ PR cross sections and partial Sc2+ PI cross sections for the ground state and for two metastable states. The Sc2+ to Sc3+ system presents a unique opportunity to obtain comprehensive state-selective information by combining results from PR and PI experiments.
