Formation and Expansion of Ablation Plasmas Produced by Pulsed Ion Beams for Thin Films Production

Numerical Analysis of Forward Expansion Characteristics of Ablated Plasma by Pulsed Ion-Beam Interaction with Al Target

“…The ion-beams are able to form ablation plasmas efficiently, because absorption and beam generation is better than that of laser. Using these characteristics, we have reported tests of a possible application by flyer acceleration using the reaction and expansion of ion beam ablation plasma [4,5] . At this university, the research has been conducting of both numerical simulation and experiment.…”

“…Yatsui et al reported that a flyer velocity of 7.7 km/s was achieved by irradiating an intense pulsed ion-beam energy density of 2 kJ/cm 2 with Al foil thickness of 50 µm [1,2] . We then developed a numerical tool for the analysis of flyer acceleration which is produced by pulsed ion beam irradiating with Al thin foil [4] . In this study, the new technique of forward expansion is introduced, while the numerical procedures are still based on the ion beam-solid material interaction concept.…”

“…We use a one-dimensional fluid model in order to simulate the dynamics of the target and the ablation plasma while incident ion beams interact with the target [3,4] . Different parts of the target are in solid, liquid and gaseous and also plasma form, which is treated as a compressible fluid without any charge effects.…”

“…C v represents the specific heat at constant volume. S indicates energy deposition (stopping power) of the ion beam based on the ion beam-target interaction [4,5] . In addition, the term H denoting energy loss due to thermal conductions is also taken account.…”

“…The subscripts ab and z are the ablation plasma and the ionization number, respectively According to the fact that the ablation plasma is produced instantaneously, the phase changed effects and electromagnetic effects are ignored [7,8] . All the above equations are solved by a difference method in the Lagrange scheme [3,4] . The physical parameters used in the simulation are listed in Table 1 and are based on the experimental conditions of a pulse power generator "ETIGO II" installed at the Extreme Energy-Density Research Institute, Nagaoka University of Technology, Japan [9,10] .…”