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Whereas our understanding of total cross sections for ionization and capture processes in ion-atom collisions is widely viewed as having arrived at a state of adequate maturity, the same cannot be said at all about the dynamics of collisions, multi-electron processes or the electron continua (in target and projectile) which are at the origin of total cross sections. We depict how these processes can be studied favourably in storage ring environments. We present examples of resonant and non-resonant electron transfer processes, radiative and non-radiative. This is elucidated via the relation of the electron nucleus bremsstrahlung at the high energy tip of the bremsstrahlung spectrum to the radiative electron capture cusp (RECC) and a new approach to determining molecular orbital binding energies in superheavy quasi-molecules in resonant KK charge transfer. [ABSTRACT FROM AUTHOR]

Theories for electron transfer to the continuum have encountered considerable difficulties to take into account the intrinsic many-electron processes in the capture channel. This may partially be attributed to large momentum transfers involved and thus collision systems are mostly not in the realm of first order perturbation theories. For this reason we have studied collision systems where simultaneously distinct competing electron transfer processes are found to be active, like radiative (RECC) and non-radiative electron capture to continuum (ECC) in the relativistic domain where one or two even active electrons are involved; here another, though distinct, transfer process, the projectile electron loss to continuum (ELC), permits additionally to study the dynamics of ionization very close to threshold. We have studied these electron transfer processes simultaneously in forward electron emission in two systems of different projectile Compton profile, U88++N2 and Sn47++N2 collisions using the forward electron spectrometer at the supersonic jet-target of the ESR storage ring. We report first results and compare with theory. [ABSTRACT FROM AUTHOR]

Double ionization of helium in collisions with 6 MeV protons (vP = 15.5 a.u.) has been explored in a kinematically complete experiment using a so-called “reaction microscope”. For the first time fully differential cross sections for positively charged particle impact have been obtained and compared to previous (e,3e) results with 2 keV electrons (vP = 12 a.u.). Differences have been found in the angular distribution of the two emitted electrons, which originate from projectile charge effects that are not considered in the first Born approximation. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

When fast highly charged ions pass a target atom or molecule at distances of a few atomic units electric fields of up to 10[sup 11] V/cm are acting on the target electrons. Depending on the field strength one or several electrons are released from the target atom by these super-strong electric pulses within the collision time of typically 10[sup -18] s. In a series of kinematically complete experiments the dynamics of the ionization process has been studied for single up to triple ionization of atoms. In these experiments the complete many-particle final state in momentum space has been mapped with high resolution. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]