Energy loss-deflection angle correlation

An indication that a strong correlation exists between energy loss and projectile deflection is found when we try to describe our measurements of 

In the calculations made, the correlation between energy loss and deflection angle is assumed to be only due to the fact that they both correspond to the same value of impact parameter b. However, the real dynamics of electrons is not considered in such interpretation. In this section 

Independent-electron model, the three-body effect 

The fact that electron excitations influence the projectile motion is taken into account when the full quantum description of scattering is made in the Born approach. The interaction with electrons and with the atomic nucleus can be considered simultaneously if the unperturbed states of the projectile are taken as states of scattering on the atomic core (the DWBA). Assuming a large energy of the projectile, we will treat the interaction with the active electron in first-order perturbation approach. 

Due to the short-wave character of projectile states, the straightforward use of DWBA approach needs enormous calculation efforts. Even with an additional, eikonal, approximation [24,25], the complexity of calculations restricts significantly the possibilities of application of this approach. One can notice, however, that the promising feature of the considered problem is that the projectile motion could be described in the quasiclassical approach. This goal can be achieved in the following way [26]. 

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Fig. 8. Dependence of mean energy loss of ions transmitted through a 20 nm gold foil on the exit angle, A ( ). The experimental results are shown by points. Solid curves represent the results of calculation where the energy loss and deflection are not correlated. The dashed lines present the results of linear response approach. The dot-dashed lines show the results of calculation where the correlation between energy loss and deflection is taken into account (see text). The plot for carbon ions includes the result of calculation for Zj = — 6 (thin solid line).

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