Steady plasma channel formation and particle acceleration in an interaction of an ultraintense laser with near-critical density plasma

A well-defined near-steady plasma channel is successfully formed in an interaction of an intense short-pulse laser with a near-critical underdense plasma. The laser is well self-focused in the plasma channel. Our 2.5-dimensional particle-in-cell simulations also demonstrate a violent electron acceleration with a effective gradient of several tens of GeV/cm by a strong longitudinal charge-separated field. At the same time, a strong ion acceleration appears at the rear plasma boundary. The results present a regime for the plasma channel formation and the particle acceleration by ultrashort laser-plasma interaction. © 2011 American Institute of Physics.