Generation of collimated quasi-mono-energetic ion beams using a double layer target with interface modulations

We propose a production of well-collimated and quasi-mono-energetic ion beams through the interaction of high- intensity laser pulse with thin overdense double layer targets. The target consists of heavy and light material layer with the modulations at the interface between them. Using extensive 2D3V PIC simulations we show that a relativistic Richtmyer-Meshkov like instability results in the generation of collimated quasi-mono-energetic beams of light ions. We compare the effects of modulations at the surface of single layer targets and at the interface between two different particle species of double layer targets. It is shown that initially small perturbations are amplified during the laser-target interaction leading to the formation of low-density regions at the positions determined by the initial perturbation geometry and high-density plasma bunches between them. The bunches, with higher density than the density in the initial foil are then accelerated by the laser radiation pressure, leading to the generation of quasi-mono-energetic, collimated ion beams.