Laser ion acceleration from tailored solid targets with micron-scale channels*

Laser ion acceleration is a promising concept for generation of fast ions using a compact laser-solid interaction setup. In our study, we theoretically investigate the feasibility of ion acceleration from the interaction of petawatt-scale laser pulses with a structured target that embodies a micron-scale channel filled with relativistically transparent plasma. Using 2D and 3D Particle-In-Cell (PIC) simulations and theoretical estimates, we show that it is possible to generate GeV-level protons with a monoenergetic-like feature in the proton energy spectrum. We attribute the acceleration mechanism to a combination of Target Normal Sheath Acceleration and Radiation Pressure Acceleration. Optimal parameters of the target are formulated theoretically and verified using 2D PIC simulations. 3D PIC simulations with the realistic laser pulse and target parameters show the feasibility of presented laser ion acceleration scheme for currently available petawatt laser facilities.