Multi-Stages Proton Acceleration Booster in Laser Plasma Interaction
  A remarkable ion energy increase is demonstrated by several-stage post-acceleration in a laser plasma interaction. Intense short-pulse laser generates a strong current by high-energy electrons accelerated, when an intense short-pulse laser illuminates a plasma target. The strong electric current creates a strong magnetic field along the high-energy electron current in plasma. During the increase phase of the magnetic field, the longitudinal inductive electric field is induced for the forward ion acceleration by the Faraday law. The inductive acceleration and the target-normal sheath acceleration in the multi stages provide a unique controllability of the ion energy. By the four-stage successive acceleration, our 2.5-dimensional particle-in-cell simulations demonstrate a remarkable increase in ion energy by a few hundreds of MeV; the maximum proton energy reaches 254MeV. 
S. Kawata, D. Sato, T. Izumiyama, T. Nagashima, D. Barada, W. M. Wang,   Q. Kong, P. X. Wang, Z. M. Sheng
physics.plasm-ph