Influence of dielectronic recombination on fast heavy-ion charge states in plasma

Correct calculation of nitrogen charge state passing through highly ionized carbon plasmas

In the present work, we reanalyze the energy loss experimental data from Cayzac et al. [Nat. Commun. 8, 15693 (2017)10.1038/ncomms15693] using our successful ion charge state theoretical model. We predict lower nitrogen charge values, from 3.5+ to 5.0+, than the ones calculated by Cayzac et al., fitting better to their data. For energy loss estimations, we use the same stopping model, so our predictions agree better with the experimental data only due to our charge state model. Different projectile electron loss and capture processes are taken into account to estimate the projectile charge state. The projectile electron loss, or ionization, with plasma ions and free electrons are considered. On the other hand, the projectile electron capture, or recombination, with plasma free or bound electrons are also considered. The projectile ionization with plasma ions is shown as the main factor that modifies the mean charge of the projectile. Here, the new Kaganovich fitting formula for this projectile ionization is used because it seems to be more accurate than Gryzinsky's fitting in the low energy range. Our charge state model fits better with experimental data than any other model in the bibliography. Thus, it should be considered in any charge state and any energy loss estimation to obtain reliable results in future work.

Role of charge transfer in heavy-ion-beam-plasma interactions at intermediate energies

In this paper we investigate the influence of the plasma properties on the charge state distribution of a swift heavy ion beam interacting with a plasma. The main finding is that the charge state in plasma can be lower than in cold matter. The charge state distribution is determined by the ionization and recombination rates which are balancing each other out. Both, ionization and recombination rates, as well as atomic excitation and decay rates, depend on the plasma parameters in different ways. These effects have been theoretically studied by Monte Carlo simulations on the example of an argon ion beam at an energy of 4MeV/u in a carbon plasma. This study covers a plasma parameter space ranging from ion densities from 10(18) to 10(23) cm(-3) and electron temperatures from 10 to 200 eV.

Energy loss and charge transfer of argon in a laser-generated carbon plasma

This Letter reports on the measurement of the energy loss and the projectile charge states of argon ions at an energy of 4  MeV/u penetrating a fully ionized carbon plasma. The plasma of n(e)≈10(20)  cm(-3) and T(e)≈180  eV is created by two laser beams at λ(Las)=532  nm incident from opposite sides on a thin carbon foil. The resulting plasma is spatially homogenous and allows us to record precise experimental data. The data show an increase of a factor of 2 in the stopping power which is in very good agreement with a specifically developed Monte Carlo code, that allows the calculation of the heavy ion beam's charge state distribution and its energy loss in the plasma.