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The hole-boring by intense laser is one of the key issues for fast ignition laser fusion, laser radiation pressure ion acceleration, generation of high energy radiations, and so on. In the hole-boring, laser pulse propagation and generation of relativistic electrons and magnetic fields are critical phenomena. When the laser intensity is higher than 1020W/cm2 and a0 is larger than 10, the self-generated quasi-static magnetic fields reaches Giga Gauss to play important roles in the electron dynamics and the laser propagation. We explore the hole-boring by a linearly and a circularly polarized laser-pulses with the 3 dimensional (3D) PIC simulations. It is found that strong longitudinal magnetic fields are generated in front of the hole-boring driven by a circular polarization laser. The circularly polarized laser is converted into spiral electromagnetic waves which include both radially polarized wave and azimuthally polarized wave in the hole. The radially polarized spiral wave generates a spiral electron beam which induces the longitudinal magnetic field. Those spiral structure-formations are essentially 3D-phenomena which are investigated in details in the first time. The spiral structure-formations may play important roles in fast ignition, radiation pressure ion acceleration, and so on.

A new fuel compression method for a fast ignition scheme is discussed. To form a high areal density fuel plasma for the ignition condition, homogenous isentropic compression (HIC) with solid spherical target is effective. We improve a multi-step pulse shape method that uses progressive shockwaves and reflected shockwaves for the compression, where a precisely controlled step-pulse laser drives the shockwaves to compress the fuel and suppress entropy increase. Another advantage of this approach is the relatively smooth high dense fuel is distributed at maximum compression time, compared to our previous design based on Kidder’s HIC method. In addition, we insert a power dip as a preconditioning before the last pulse step to reduce the electron and ion temperature near critical density. As a result, an optimum implosion is designed using 245 kJ of implosion laser energy to meet the ignition condition.