Dynamical mixing effects in the transport of fast hydrogenic ions through solids

International audienceAtomic physics experiments, dedicated to the study of the production and the transport of projectile excited states have been performed for different systems, in the regime of high to intermediate velocity, using the GANIL facilities in Caen (France). High-resolution x-ray spectroscopy has been applied to probe the earlier first stage of ion-solid interaction from a very short time scale (10-15 s), corresponding to single collision conditions, up to equilibrium [1,3]. These experiments have allowed to test the production and the transport of projectile excited states with different degrees of sensitivity to either individual collision processes (the collisional part) and/or to the dynamical screening associated to the wake field induced in the medium by the passage of the projectile. These two competing processes have not the same time scale and do not lead to the same effects on the projectile excited state populations. In parallel, two types of ion transport description have been developed, which take into account both aspects of the target response but with different approximations. One is a quantum mechanical approach, solving a set of master equations [2, 3, 5]. The second is based on a Monte Carlo simulation and can be performed using both classical and quantum approaches in the calculation [4-7]. Comparison with theories will be presented, and the validity of the approximations done in the two different approaches will be discussed. 1. Vernhet D et al 1998 J. Phys. B. 31, 117-119 2. Rozet J-P et al 1999 J. Phys. B. 32, 4677-4696 3. Vernhet D et al 2000 AIP 500, 666-676 4. Reinhold C. O. et al 2000 J. Phys. B 33, L111-L117 5. Vernhet D et al 2001 Physica Scripta T92, 233-236 6. Minami T et al 2002 Phys. Rev. A 65, 032901,1-11 7. Minami T et al 2003 NIM B 205, 818-82