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Correlated many-particle dynamics in Coulombic systems, which is one of the unsolved fundamental problems in AMO-physics, can now be experimentally approached with so far unprecedented completeness and precision. The recent development of the COLTRIMS technique (COLd Target Recoil Ion Momentum Spectroscopy) provides a coincident multi-fragment imaging technique for eV and sub-eV fragment detection. In its completeness it is as powerful as the bubble chamber in high energy physics. In recent benchmark experiments quasi snapshots (duration as short as an attosecond) of the correlated dynamics between electrons and nuclei have been made for atomic and molecular objects. This new imaging technique has opened a powerful observation window into the hidden world of many-particle dynamics.

Cold Target Recoil Ion Momentum Spectroscopy allows the detection of the three-dimensional momentum vector of the recoiling product ion from ion, electron or photon atom collisions with 4π solid angle and high resolution. It can be combined with large area position-sensitive detectors for electron detection or measurement of the projectile charge-state and scattering angle. Such ‘reaction microscopes’ cover the full correlated momentum space of all fragments of an atomic reaction yielding kinematically complete information for each reaction event. For the first time in atomic collision physics fully differential data became available in the sense that not only the momenta of all fragments, but also the complete momentum space is observed in one experiment. Recent results achieved with this new technique for slow p-He collisions and threshold photo ionization of He will be discussed.

Ion-beam mixing at the Sb/Ni interface was investigated with a wide range of ions (He, Ne, Ar, Xe, Pb) and beam energies (40–900 keV). The irradiations were carried out at 77 and 300 K on Sb/Ni bilayers and on Ni and Sb marker layers embedded in Sb and Ni, respectively. Atomic intermixing was determined by means of Rutherford backscattering spectrometry. The bilayer mixing rates were extracted from the concentration profiles at the interface observed after low-dose irradiations (≤20 dpa). A nearly linear dependence of the low temperature mixing rates on the damage energy FD deposited at the interface was found for the He, Ne, Ar and Xe irradiations. This points to a local rather than a global thermal spike mixing mechanism. After Pb-irradiation an enhanced mixing efficiency was observed, possibly indicating the transition from local to global spike formation. At 300 K, radiation-enhanced diffusion contributes to the mixing process.

A survey is given on the modifications of 30–300 nm thin TiN films on various substrates under high-fluence irradiation with 80–700 keV Ar, Kr and Xe ions. In particular, the effects of sputtering, interface mixing and blister formation were investigated. The results were obtained by combining several depth-profiling techniques, such as resonant nuclear reaction analysis (RNRA), Rutherford backscattering spectroscopy (RBS) and proton-induced X-ray emission (PIXE). Scanning electron microscopy and adhesion tests were also applied to the films. Optimal interface mixing parameters are proposed on the basis of the measured sputtering and mixing rates.

TiN films of 30–300 nm thickness, deposited onto stainless steel via magnetron sputtering, and 10 μm thick Ti foils were irradiated with 80–360 keV Xe+ ions at influences of φ = 1015–1017 ions/cm2. The Xe content was depth-profiled by means of 900 keV He++ Rutherford backscattering. Irradiations of films with a thickness exceeding the ion range (at 80 and 250 keV) led to saturation effects due to sputtering and outdiffusion from the near-surface region. The sputtering yields deduced at low Xe fluences were compared to calculations for mono-elemental and compound sputtering. Surface blistering was observed after 250 keV saturation implantation into Ti. For TiN layers with a thickness comparable to the ion range, precipitation of the mixing gas at the interface was observed which finally led to the destruction of the layers. The dependence of the Xe fraction accumulated in the interface is discussed in terms of thermal-spike calculations.