[en] A project is under way to establish an experimental capability for low-energy multicharged ion research in Reno. At the heart of this facility will be a CAPRICE ECR ion source with a strengthened hexapole magnetic field. The ion source will be operated at a microwave frequency of 14 GHz and an accel-decel primary beam transport system is being considered. One novel experimental development planned for this facility is a crossed-beams apparatus designed for coincidence measurements of electron-impact ionization of multicharged ions. The objective is direct identification of inner-shell contributions to the ionization cross section via Auger electron spectroscopy. An overview of the project and research plans will be presented

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[en] 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 the inverse processes of 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

[en] The results of an investigation on the production of Group IIA atomic and molecular negative ion beams formed in a cesium-sputter negative ion source are presented. The sputtering material was formed by pressing pellets of stoichiometric mixtures of the Group IIA element carbonates and 10% copper powder. Negative ions of several alkaline-earth elements and their oxides have been observed. Beam intensities as high as 180 pA have been observed for Sr^-and 20 nA for SrO^-. (orig.)

[en] High-resolution absolute experimental measurements and theory are compared for photoionization of metastable oxygen ions

[en] Full text: The principle of detailed balance relates the cross sections σ_PR for photorecombination (PR) and σ_PI for photoionization (PI) of ions on a state-to-state level. Measuring one or the other of the two cross sections provides direct information about the time-reversed process. Measurements carried out at the Advanced Light Source, Berkeley, for PI on a number of ion species A^q+ are compared with experimental results for PR of A ^(q+1)+ ions obtained at the heavy-ion storage rings in Heidelberg and Stockholm. From such comparisons, state selective cross sections can be inferred both for PR and PI. Both experimental approaches provide outstanding possibilities for high-resolution spectroscopy of multiply excited states. Particular attention was devoted to K-shell-excited states of few-electron ions such as B²⁺ and C³⁺ to establish the validity of the present approach which makes use of the conservation of time-reversal symmetry in atomic collisions. Starting from unexplained discrepancies between theory and experiment in the search for interference between dielectronic recombination (DR) and radiative recombination (RR) of argonlike ions, the investigation of 'giant' resonances in the potassium isoelectronic sequence has become a major project. The resonance features investigated in this context are associated with photoexcitation and subsequent Super-Koster-Cronig transitions of doubly excited states in Ca⁺, Sc²⁺, and Ti³⁺ ions which can also be populated by electron-ion recombination experiments with the related isonuclear argonlike species. The investigations provide convincing evidence of the presence of interference between DR and RR even if their relative contributions to the observed cross section are very asymmetric

[en] We have measured the total cross section for photodetachment of the Na^- ion over the photon energy range 30-51 eV. Electron detachment leads predominantly to the production of Na⁺ ions in this energy range. The structures in the measured cross section are associated with correlated processes involving the detachment or excitation of a 2p core electron, processes which are often accompanied by the excitation of one or more valence electrons. The most prominent feature in the cross section is a strong resonance associated with the excitation of a 2p electron from the core and a 3s valence electron. As in previous experiments on double excitation of valence electrons, electron correlation is seen to play an important role in the dynamics of negative ions. (author). Letter-to-the-editor

[en] The electron affinity of lanthanum has been measured using laser photoelectron energy spectroscopy. This is the first electron affinity measurement for lanthanum and one of the first measurements of an electron affinity of a rare-earth series element. The electron affinity of lanthanum was measured to be 0.47±0.02 eV. At least one bound excited state of La^- was also observed in the photoelectron spectra, and the binding energy relative to the ground state of lanthanum was measured as 0.17±0.02 eV. The present experimental measurements are compared to a recent calculation. (author). Letter-to-the-editor