[en] An electromagnetic shaker is described of a simple design suitable for operation in the radioactive environment. It essentially consists of two electromagnetic coils and of a double-arm moving core firmly attached to the shaker work bench. The shaker vibrates in the horizontal direction. (J.B.)

[en] Helium single ionization by 3.6 MeV/u Ni²⁴⁺ impact was explored in a kinematically complete experiment. Combining a high-resolution recoil-ion momentum spectrometer (ΔE_Rparallel∼±12 μeV) with a novel 4π open-quotes soft-electronclose quotes (0 eV ≤ E_e ≤ 50 eV) analyzer all 3 momentum components of both the emitted recoil ion and electron were recorded simultaneously. More than 90% of the soft electrons are ejected in forward direction in agreement with CTMC predictions. The backwards recoiling He¹⁺-ion compensates the electron momentum completely in the longitudinal (except of the Q-value) and partly in the transverse direction. Energy losses of the 208 MeV projectile as small as ΔE_p/E_p ∼ 10^-8 become detectable

[en] We consider binary-encounter electron emission in fast nonrelativistic collisions assisted by a low-frequency electromagnetic field. The field is assumed to have linear polarization and to be weak compared to a typical atomic field. Our work suggests that the electromagnetic field can have a profound effect on binary-encounter electron emission. (author)

[en] Recently, a new method of analysing electron correlations based on intensity interferometry has been applied to double ionization of He and Ne by fast ion impact [1]. The data reveal sensitively correlation effects while they appear to be very insensitive to the collision dynamics. In order to analyse the role of the initial state electron correlation a statistically defined correlation function based on intensity interferometry was calculated for the ground state of He. In a comparative study of model wave functions we demonstrate that correlation can be considered from a statistical point of view which offers a new tool to study correlation effects in many-particle systems. (orig.)

[en] The correspondence between the ionization of light atoms by charged particle impact (virtual photons) and by photoabsorption (real photons) is analysed. It is shown that the 'genuine' photo-like mechanism in the impact ionization of light targets can already be observed at collision energies corresponding to the Lorentz factor γ > or approx. 10, but that it starts to dominate electron emission only at γ > or approx. 1000. It is demonstrated that the non-relativistic Bethe-Born and Weizsaecker-Williams approximations represent extremely different limits of the impact ionization but that 'by chance' their results are formally close for electron emission in non-relativistic fast collisions. (author)

[en] The book reviews the progress achieved over the last decade in the study of collisions between an ion and an atom in which both the atomic particles carry electrons and can undergo transitions between their internal states - including continua. It presents the detailed considerations of different theoretical approaches, that can be used to describe collisions of structured atomic particles for the very broad interval of impact energies ranging from 0.5-1 MeV/u till extreme relativistic energies where the collision velocity very closely approaches the speed of light. (orig.)

[en] We consider the application of the Lorentz and Coulomb gauges to treat collisions of relativistic charged projectiles with light atomic targets. We use the approach where the nonrelativistic description of the target is combined with the relativistic treatment of the projectile field. It is shown that the Coulomb gauge has a great advantage as compared with the Lorentz one if exact eigenstates of the target nonrelativistic Hamiltonian are not available. The reasons for this are discussed. (author)

[en] An interesting realization of the fundamental four-body problem: double ionization of helium in superintense electromagnetic fields generated by highly charged ions in relativistic collisions is considered. It is shown how the simultaneous interaction of such fields with all the three target constituents (which is not described by a first-order theory) strongly influences the collision dynamics even at very high collision energies and how the genuine photo-like emission pattern may emerge in collisions at extreme relativistic energies. A very good agreement with available experimental data is found

[en] Full text: We consider the process of mutual projectile-target ionization in relativistic collisions between light hydrogen-like ions and hydrogen and helium atoms: i) X^Z+(1s) + H(1s) → X^(Z+1)+ + H⁺ + 2e^- and ii) X^Z+(1s) + He(1s²) → X^(Z+1)+ + He⁺(1s) + 2e^-. At high collision velocities and for not too heavy projectiles, where Z/v << 1 with v being the collision velocity, the mutual ionization proceeds via the two-center dielectronic interaction (TCDI) which couples two electrons initially bound in the different colliding particles. Several aspects of the electron emission from the target are explored in detail for the case when the final internal continuum state of the projectile is not detected, i.e. when the integration is performed in calculations over all possible final continuum states of the electron ejected from the projectile. Our results show that the relativistic effects in the TCDI clearly manifest themselves in the spectra of electrons emitted from the target. The character and magnitude of these manifestations suggest that these effects are quite accessible for experimental observations

[en] We consider the 1s-1s charge-exchange process in collisions between a positronium and proton (anti-proton) in the presence of a relatively weak low-frequency electromagnetic field. The consideration shows that, because of the field-induced modification of the (final) continuum states of the colliding system, the capture process can be accompanied by substantial energy exchange with the field. This exchange first of all results in the change in the energy spectrum of the outgoing positron (electron). Some arguments are also given that the presence of the field might influence the total capture cross section. (author)