Enhanced Target Normal Sheath Acceleration of heavy ions using nanostructured targets

Target normal sheath acceleration (TNSA) is one of the best-known laser-plasma mechanism of ion acceleration, capable of generating multi-MeV collimated ion beams. The conventional TNSA (flat-foil target) has a few inherent limitations, such as poor coupling efficiency of the laser energy into hot electrons and short ion acceleration distance at the back of the target. By means of a 3D particle-in-cell simulations, we show that the interaction of ultra-intense ultrashort laser pulses with periodic nano-trenched M-shaped Si structures [1] can produce highly collimated, energetic vacuum-accelerated [2] electron bunches in the nano-trench. This results in a substantial enhancement in both the total and cutoff energies of the produced Si ion beams. The numerical studies reveal the optimal laser-target parameters, such as nano-trench thickness, periodicity of structures, laser wavelengths, and energies.

 

1. [1] Shcherbakov, M.R., Sartorello, G., Zhang, S. et al. Nat Commun 14, 6688 (2023).
   
   [2] Jiang S. et al., Phys. Rev. Lett.,116, 085002 (2016); Naumova N. et. al., Phys. Rev. Lett., 93, 195003, 2004; Curtis A., Calvi C., Tinsley J. et al., Nat. Comm. 9, 1077 (2018).