Numerical investigation on self-focusing during laser electron acceleration in a magnetized plasma

The magnetic field is known to play an important role in laser-plasma based accelerators. Due to the magnetic field, the laser-induced velocity of the plasma electrons increases significantly. Therefore, the laser can coherently accelerate the electrons to high energy in the presence of a magnetic field. The self-focusing of a high-intensity laser in the presence of a magnetic field is affected during this acceleration process. The relativistic mass effect and the magnetic field contribute to the nonlinear dielectric response of the plasma. The effect of a magnetic field on the nonlinearity becomes important when the laser frequency and the electron cyclotron frequency are of the same magnitude. At resonance, a significant enhancement in self-focusing of the laser is observed during acceleration in a plasma.