QED Approach Research Articles

Auger emission and transfer ionisation in high energy Li3+ and He(H2) collisions - a QED approach

Ion induced Auger emission leading to transfer ionisation (ATI) in high energy ion-atom collisions is computed for Li3+ on H2 and He targets. QED computations for transfer ionisation (TI), charge transfer (CT) and double capture (DC) were recently reported in two papers (Bhattacharyya et al., 1988 [1], Bhattacharyya, 1989 [2]) subsequently referred to as paper I and II, respectively. Double capture of electrons leading to transfer ionisation ATI is here done in a similar technique. The cross section for ATI is found to lie between 0.1% to 0.2% of the sum of the cross sections for TI and ATI events.

High-energy electron capture by fully stripped ions from He atoms -a QED approach

One-electron-capture cross sections sigma CT and transfer ionisation cross sections sigma TI are calculated for fully stripped ions colliding with He atoms at energies above 100 keV amu-1 in a relativistic covariant manner. Numerical results for Li3- on He are presented and compared with existing experimental data and numerical calculations. The energy distribution of the emitted electron due to transfer ionisation (TI), when electron capture occurs into the Li2+(1s) state, is discussed.

On the QED approach to frequency shifts

We comment on and correct recent works which 1) discuss the effect of the rotating wave app of radiative frequency shifts and 2) calculate level and frequency shifts by dispersion relations.