Characterization of ion beams from solid targets driven by a 0.5 kJ short-pulse laser*

Energetic particles, including electrons, ions and secondary particles, are produced by directing an intense laser pulse at a target material. The laser-driven ion beam may find applications in inertial fusion or high-resolution images of both static and dynamic objects in next-generation radiography to probe materials and plasmas in extreme environments. To scale up ion beam production suitable for these applications, we have conducted experiments using a 0.5kJ sub-ps laser at the Omega-EP laser facility to characterize the laser-driven ion beam from a variety of solid targets, including CH/CD/Kapton sub-micron thin films, low-density CD foams and flat CH foil targets of micron-scale thickness, encompassing ion acceleration regimes including Target Normal Sheath Acceleration (TNSA), Radiation Pressure Acceleration (RPA) or Collisionless Shock Acceleration (CSA), and Relativistic Transparency (RT). Ion acceleration with/without Compound Parabolic Concentrator (CPC) cone have also been compared. We obtained beam spectra and spatial source profiles, and found that ~700-800nm foil target achieved the best ion yield among the targets tested. Preliminary static and dynamic radiography were also conducted using these laser-driven ion beams. The different characteristics of the ion beams produced from these targets will be summarized and compared with simulations and understandings/scaling from the literature.