Parametric scalings of laser driven protons using a high repetition rate tape drive target system

A series of experiments were carried out using the 200 TW laser facility at LLP SJTU aiming to explore parametric scalings of laser driven protons employing a low cost and stable high repetition rate tape drive target system. For numerous laser shots at a repetition rate of ∼0.2 Hz with maximum laser intensity up to ∼5 × 1019 W/cm proton beams maximum energy were measured for variations in laser energy, focal spot and pulse duration. The data suggests that the proton maximum energy scales as I∼0.6 while changing the incident laser energy. Scaling trends are in good agreement with the previously reported experimental results and theoretical models. This study may provide a platform to investigate the characteristics of proton beams, such as source size and angular dispersion at a repetition rate required for many potential applications.