Dynamical substate mixing of fast ions in solids : a density matrix approach

We have developed an exploratory model that allows for the temporal evolution of the capture density matrix of a hydrogen-like ion subject to dynamical mixing in solid targets. We show that certain selection rules apply, in effect simplifying the problem to the calculation of reduced (2 × 2) density matrices. This model permits us to extract, from available experimental results, values for the effective wake field and some of the diagonal and off-diagonal capture density matrix elements. Assessment of the approach is discussed in the light of recent experiments