Modeling of ns-LPP plume expansion for Stopping Power studies

LPPs obtained via ns-pulsed laser ablation in the IL ∼ 1012 W/cm2 intensity regime on bulk and structured targets have been extensively investigated and represent a potential environment to perform SP measurements of incident charged radiation in plasma. Several theoretical models have been proposed for both the description of the LPPs dynamical evolution and the energy loss of swift charged particles inside a plasma plume. On the one hand, the well-known hydrodynamics expansion model proposed by Anisimov [1], initially introduced in the context of PLD, solves the gas dynamical equations under the basic hypothesis that the plasma expands selfsimilarly, adiabatically, and isoentropically in vacuum: a special solution of the Eulero’s equations gives out the plasma density and temperature profiles versus time. On the other hand, the standard stopping model (SSM) [2] in plasma provides an estimation of the energy loss of charged particles in an ionized medium, taking into account the free and bound electrons contributions, once the plasma parameters (density, temperature, ionization degree) are known. Yet, the lack of systematic experimental characterization and the large uncertainties between the SP models near the Bragg peak demand for further investigations.