Recent results at LULI on ion acceleration using ultra-intense lasers and overview of the future multi-PW Apollon laser facility
Recent results obtained in the area of proton acceleration by ultra-intense lasers will be presented. First, we will discuss how magnetostatic fields self-generated on the target surface may pose a fundamental limit with respect to ion acceleration by intense electron sheath. By magnetizing the sheath electrons as well as deflecting the protons off the accelerating region, these fields degrade the energy transfer from the electrons to the protons. Second, we will show that high-energy protons can be alternatively accelerated by collisionless shocks driven in low-density plasmas by intense, mid-infrared laser pulses. Up to 45 MeV highly directional protons are recorded using a laser intensity of 1020 W/cm2, outperforming what is produced using the standard electrostatic acceleration scheme using the same laser. Last, we will show that using the same laser, also shock-accelerated protons can be obtained from over-critical gas jets. Finally, we will present the APOLLON-10P user’s facility laser system, which is a Ti:Sa based laser that aims at ultimately deliver 150 J in 15 femtosecond pulses (10 PW). The facility will host two target areas; after focusing, intensities up to 2x1022 W/cm2 will be delivered to the experimentalists.