Collimation of Hot Electrons by Spontaneous Magnetic Fields in the Interaction of a Short-Pulse and High-Intensity Laser with a Relativistic Plasma

The emittance of hot electrons produced from the interaction of a short-pulse and high intense laser with a relativistic plasma is an obstacle for igniting hot spot formation in the concept of fast ignition scheme for inertial confinement fusion. Our numerical results show that the tens of megagauss spontaneous quasistatic magnetic field generated by the short-pulse and high-intensity laser with a relativistic plasma may collimate hot electron motion. The spontaneous axial magnetic field driven by a helical current, parallel to laser propagation, behaves as a guiding center with a submicron Larmor radius. And the spontaneous toroidal magnetic field driven by ponderomotive current causes a pinch effect on hot electrons