Sustained Acceleration of Over-dense Plasmas by Colliding Laser Pulses
  We review recent PIC simulation results which show that double-sided irradiaton of a thin overdense plasma slab by ultra-intense laser pulses from both sides can lead to sustained comoving acceleration of surface electrons to energies much higher than the conventional ponderomotive limit. The acceleration stops only when the electrons drift transversely out of the laser beam. We show results of parameter studies based on this concept and discuss future laser experiments that can be used to test these computer results. 
E. Liang