Electronic stopping of slow molecular ions in solids

Abstract

Energy loss measurements were made for 12.5-130 keV per nucleon H+ and H: on carbon and aluminium foils. For incident H i , both H + and H i are transmitted; the energy per nucleon of the latter being lower than that of transmitted H + , at low energies. The theory shows this is due to interference effects in the binary excitation of target electrons by the spatially correlated protons and suggests that transmitted H: results from di-protons travelling inside the solid with the internuclear axis aligned close to the direction of motion.

Stopping power of large homonuclear clusters: Influence of cluster structure

“…The system is the same as in Fig. 3 [6,7]. A recent experiment using larger clusters [20] shows clearly, similar to the present study, a defect of stopping at low velocities and an excess of stopping at high velocities.…”

“…(6) for the models of cluster structure specified above. The separation of intra-and intermolecular efFects according to Eq.…”

“…By excluding clusters of low velocity we can ignore complications due to nonlinearity in the screening of the cluster charge [21], and also the effects of nuclear interaction on the energy loss, since electronic stopping is the dominant mechanism in the velocity range investigated here [22,23]. (6) where the function F(k) represents the structure factor [25] for the cluster, II. BASIC MODEL F(k)=1+n f d rgd(r) (7) Consider a cluster consisting of N atoms with relative positions r;, each atom having a charge Z, and moving with velocity v through a stopping medium.…”

“…(6) Equation (6) can be applied to two limiting cases, the independent-particle limit and the united-atom limit. The first case may be realized by making all internuclear distances so large that the term sin(kr)/(kr) in Eq.…”

Energy loss of swift H 3 + -molecule ions in carbon foils

“…Since the pioneering article of Brandt et al [4], who studied the stopping power of swift molecules in solids, a lot of theoretical work has been developed [5]- [13]. Experiments have been mainly done with hydrogen-molecular ions, H + n , ranging from small [14]- [18] to intermediate [19] values of n.…”