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The high-power iodine laser PALS was used to generate highly charged Ta ions and to study non-linear processes in laser-produced plasma. Longitudinal structures of the expanding plasma, obtained by using an X-ray streak camera on a time scale ∼ 2 ns, are presented. Various bright spots (moon-like, half-moon-like), expansion-path curvature and even their splitting were recorded. These phenomena are ascribed to the effect of the magnetic field that is self-generated at high laser intensities. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO) films can be employed as thin ion strippers in an accelerator. They show some advantages with respect to the graphite foils, due to their high thermal and electrical conductivities, low density, high mechanical resistance and high stability. The preparation method of the graphene-based films and their physical characterization are presented and discussed. Thin graphene oxide (GO) films with a thickness of from 0.5 up to 2.0 μm have been synthesized and studied to be used as an ion extractor (stripper) in the 3.0 MV Tandetron of the CANAM Laboratory at the Nuclear Physics Institute in Rez, Czech Republic. GO is transformed to rGO also by low ion beam doses. Measurements of stripper efficiency, as the ion transmission factor of films, have been carried out by accelerating different ions, from helium to carbon, having energies from 1.0 up to 16 MeV, and by using different charge states and a current density ranging between about 10 nA/cm2 and 2 μA/cm2. The ion fluence at which the so-obtained graphene oxide films can be undergone exceeds a dose of 1 × 1016 particles/cm2. Furthermore, these stripper films have demonstrated a significantly high charge production, comparable to that of the graphite films. However, the higher mechanical resistance represents an undiscussed advantage with respect to the graphite films. • Graphene oxide (GO) can be used as efficient thin foils for MeV ion stripping. • GO is reduced by the ion irradiation transforming it in high conductive material. • Reduced GO has a low density and a mechanical resistance higher than graphite foils. • The transmission stripping efficiency of rGO is similar to that of graphite. • The lifetime of rGO stripper is higher than graphite for light energetic ions. [ABSTRACT FROM AUTHOR]