S Suárez

Experimental and theoretical results on electron emission in collisions between He targets and dressed Liq+ (q = 1, 2) projectiles

We investigate experimentally and theoretically the electron emission in collisions between He atoms and (q = 1, 2) projectiles at intermediate to high incident energies. We report on measured absolute values of double-differential cross-sections, as a function of the emitted electron energy and angle, at a collision energy of 440 keV u−1. The different contributions from target ionization, projectile ionization, and simultaneous target–projectile ionization are calculated with the quantum-mechanical continuum distorted wave and continuum distorted wave–eikonal initial state models, and with classical trajectory Monte Carlo simulations. There is an overall good agreement of the calculations with the experimental data for electron emission cross-sections.

Experimental and theoretical results on electron emission from helium by the impact of bare Li3+ ions

We investigate experimentally and theoretically the ionization of helium atoms by the impact of bare Li3 + projectiles at intermediate and high incident energies. We report on measured absolute values of doubly differential cross-sections, as a function of the emitted electron energies and angles, at collision energies of 200 and 440 keV u−1. Different physical aspects of the reaction are interpreted theoretically by comparison of the data with quantum-mechanical continuum distorted wave and continuum distorted wave–eikonal initial state calculations as well as classical trajectory Monte Carlo simulations. There is an overall good agreement of the calculations with the experimental data, which improves considerably for higher collision energies.

Electron emission in collisions of dressed ions with He atoms

We present theoretical and experimental results for angular and energy distributions of electrons emitted in collisions of B2+ with He atoms. In particular, we analyze the cusp formed by projectile Electron Loss to Continuum (ELC) and Electron Capture to Continuum (ECC). The cusp shape dependence on the electronic initial state is discussed and compared with our previous measurements on Li+ + He. The projectile incident energy was about 414 keV/u and the electron detection angle was varied between 0° and 150°. The experimental data is compared with three-body quantum Continuum-Distorted-Wave calculations.

CDW and CDW-EIS calculations of simultaneous ionization in collisions between dressed projectiles and atomic targets

The role of simultaneous electron emission in collision between dressed ions and atoms is discussed. Methods of calculations within quantum-mechanical Continuum-Distorted- Wave (CDW) and Continuum-distorted Wave-Eikonal-Initial-State (CDW-EIS) models are revisited and improved within a semiclassical probabilistic approach.

Electron loss in collisions of dressed projectiles with atoms and molecules

Energy distributions of electrons emitted with energies corresponding to the region of the electron-loss-cusp (ELP) were measured for collisions of several neutral projectiles with atoms and small molecules. Besides the well known projectile ELP cusp, a second structure is observed for Li and Na projectiles. Comparing the experimental data with four-body CTMC calculations we analise the origin of these structures in terms of nuclear-electron and electron-electron interactions.

Electron emission in collisions between dressed Alq+ ions with He targets

Experimental and theoretical results are presented for electron emission in collisions between dressed Alq+ ions and atomic He targets. The experimental data are compared with a four-body CTMC model and two distorted wave models, namely the CDW and CDW-EIS. The contribution to total electron emission spectra from the ionisation of each collision center and as well as the simultaneous ionisation can be assessed separately.

Electron emission from dressed projectiles in collision with atoms and molecules at intermediate energies

Angular and energy distributions of electron emitted from dressed ions and neutral atoms in collisions with atoms and molecules were measured for intermediate incident energies. Effects of the initial state of the projectile electron were studied using distorted wave and CTMC calculations. Experiments carried out on collisions with He, Li, H, Ne, and Ar show that the electron loss distributions depend very strongly on the target.

Characteristic electron emission in the production of by impact on Ar

We have measured recoil ions in coincidence with electrons emitted at with respect to the beam direction, in collisions of 50, 120 and 210 keV on Ar. For these energies the ratio between the yields of the recoil ions and , as a function of electron velocity, presents a distinctive peak at a velocity close to that of the projectile. Data with neutral projectiles , in contrast, do not show such a structure. Measurements with and projectiles on Ar at 25 keV were also performed, confirming that the characteristic structure is associated with the projectile net charge.