Particle-in-cell simulations of ultra intense laser pulses propagating through overdense plasma for fast-ignitor and radiography applications

Zohar (two-dimensions, particle-in-cell) [C. K. Birdsall and A. B. Langdon, Plasma Physics via Computer Simulation (McGraw-Hill, New York, 1985)] simu lations of ultra intense laser beams boring into overdense plasmas whose pa rameters are guided by the fast-ignitor concept and radiography application s are presented. Complex low frequency magnetic field structures, narrow ch annel formation, and beam deflection are all evident. Particle tracking dia gnostics elucidate the nature of the currents that produce and interact wit h these static magnetic fields which are larger than 10(9) G for simulation s at 10(21) W/cm(2) in a 50n(c) plasma. Tracking electron orbits provides a more complete understanding of the hot electron generation as the short pu lse, high intensity laser penetrates overdense plasma. Particles which cons titute the current in the narrow channel are partially confined by the low frequency magnetic field. In contrast, the return current particles on the outside of the channel are defocused by the high magnetic field and move aw ay from the channel. [S1070-664X(99)91605-1].