[en] Single electron capture by triply charged Ne projectiles in He and Ne has been studied at low collision energies (600 eV) showing the dominant mechanims to be due to transfer excitation and capture of inner target electrons. The results are compared with predictions of various classical models and improved multi-channel LZ calculations. Information is obtained on the coupling strength relevant for both types of processes

[en] Single electron capture by triply charged rare gas ions colliding with various rare gas atoms has been studied by means of translational energy spectroscopy (TES) at low collision energies. The final state population is discussed in terms of the so-called reaction window predicted by various models as well as by extended multi-channel Landau Zener calculations (MCLZ). The analysis shows the limitations of such model descriptions and yields information on the coupling strength in the case of inner shell capture or multi-electron processes. (orig.)

[en] We studied the fragmentation dynamics of small molecules, as e.g. N₂ or CH₄, in collisions with slow He²⁺ and Ar³⁺ ions. A combination of position- and time-sensitive detectors allows the coincident measurement of the generated electrons and fragment ions as well as of those projectiles involved in a charge exchange process. The kinetic energy released by the molecular fragments clearly depends on the number of electrons stabilized at the projectile. For example, the measured N⁺+N⁺ energy distributions in direct ionization processes are considerably broader than those corresponding to capture processes

[en] Single electron capture by triply charged rare gas ions colliding with various rare gas atoms has been studied by means of translational energy spectroscopy (TES) at low collision energies. The final state population is discussed in terms of the so-called reaction window predicted by various models as well as by extended multichannel Landau Zener calculations (MCLZ). The analysis shows the limitations of such model descriptions and yields information on the coupling strength in the case of inner shell capture or multi-electron processes. (orig.)

[en] We have studied the fragmentation of thymidine and deoxyadenosine induced by slow multiply charged ions. The measured mass spectra specify as an important reaction channel the separation of the molecules into their basic and osidic parts, combined with some structural modifications. In particular for higher projectile charges singly and doubly charged small-size fragments (m<100) are produced, but also the formation of large molecules (modified dimers or trimers) occurs in the sputtering process. The sputtering yield increases with the charge state, the grazing angle as well as the kinetic energy of the projectile

[en] Multiple ionisation of rare gas atoms by electron impact has been studied experimentally close to the ionisation thresholds. In this energy range the cross sections are described by threshold laws, yielding reasonable agreement with theory for He and Ne. In the heavier targets the exponent value is found to be smaller than predicted and the results can be interpreted in terms of a pure statistical theory

[en] We have studied the energy loss of slow (velocity v∼0.06 a.u.) highly charged Ar⁹⁺ ions scattered at large angles from a clean Au(1 1 1) single crystal surface. The influence of the scattering geometry on the energy loss has been investigated for different incidence angles (5 deg. ≤ψ≤37.5 deg.) and scattering angles (30 deg. ≤θ≤75 deg.). At large angles (ψ=37.5 deg., θ=75 deg.), the main peak in the measured energy spectrum agrees well with the position expected for binary elastic scattering. With decreasing incidence angle a shift of the 'binary peak' to lower energy is observed, and for decreasing scattering angles, a shift of the binary peak to higher energy than calculated by kinematics is found. The additional energy loss seen at small ψ (ψ=5 deg.) is interpreted by inelastic energy loss. A model calculation which combines s rate-equation description of Auger cascades, recapture to the surface with a Firsov type model and image charge acceleration during ion-surface interaction is used to describe the data

[en] The multiple ionization and fragmentation of methane was studied in collisions with slow highly charged Xe-ions utilizing a position- and time-sensitive multi-particle detector. The coincident measurement of the momenta of correlated fragment ions allows a detailed analysis of the fragmentation kinematics and the kinetic energy release can be derived for each break-up into charged fragments. Among the observed processes the spectra for H⁺ + CH₃⁺ and H₂⁺ + CH₂⁺ showed the highest sensitivity to projectile characteristics

[en] Ion irradiation of SiO₂ quartz at medium energy induces damage in the bulk as well as modification on the surface. To make a correlation between the bulk and the surface phenomena, AFM investigations on the SiO₂ quartz surfaces, irradiated with Ni, Kr and Pb ions were performed. To avoid the overlap of the defects, the fluences were 5x10⁹, 1x10¹⁰ and 6x10¹⁰ ions/cm². The specific energies were between 2 and 6 MeV/u. The ion-induced damage surface was studied using a Digital Nanoscope III working in Tapping Mode, at ambient conditions. We observed hillocks induced by the irradiation with the different ions. The radius of hillocks has been compared with the radius of the tracks induced in the bulk. At high energy loss for dE/dx larger than 7 keV/nm, there is one hillock per ion, contrary to the observations of Wilson et al

[en] The energy dependence of neutralization of slow highly charged Ar^q+ (q=7,9,13) ions scattered at large angle (Ψ=37.5 deg., θ=75 deg.) from a clean Au(1 1 1) single crystal surface was studied for incidence energies E₀=2, 4 and 8 keV. For Ar⁷⁺ the neutralization yield is almost constant for all incoming ion energies, while with L-shell vacancies (q=9,13), the neutralization yield increases with increasing energy. The experimental results are compared with model calculations that contain side-feeding process of the Ar inner shells, the electron recapture to the surface and the Auger transitions during the ion-surface interaction