Exploiting novel liquid sheet targets for the generation of bright MeV proton beams

Laser-plasma acceleration has enormous potential to provide compact sources of ultra-short ion beams. However, several factors hamper their wider adoption, such as the low shot-to-shot stability, large beam divergence and the difficulty of high-repetition rate operation. In this talk I will outline an approach for overcoming these challenges by using an automated experimental setup incorporating a novel liquid sheet target, developed by collaborators at the SLAC National Accelerator Laboratory. I will report on recent experiments at the GEMINI TA2 laser facility (10 TW, 5 Hz) which demonstrated stable acceleration of few MeV proton beams with high flux and low-divergence proton beams in comparison to typical laser-accelerated ion beams. Supporting PIC simulations have shown that the presence of background vapour around the target plays an important role in the observed collimation of the proton beam. The measured proton beams are already suitable for applications requiring high proton flux and the platform can be extended to kHz repetition rates or higher laser energies extending the utility of the source to a wide range of applications in radiobiology, materials science and fundamental physics.