Investigation the influence of injection angle on electron acceleration in laser wake-field accelerator with the presence of external magnetic field

In this paper, the influence of initial momentum and the injection angle of electron in to the magnetized plasma in a laser wake-field accelerator have been studied.It has been seen that the use of external magnetic field in the opposite direction of laser pulse propagation leads to an increase in the wake-field amplitude and a decrease in laser pulse group velocity in comparison to the use of external magnetic field in same direction of laser pulse propagation or unmagnetized plasma case. The results show, the effect of initial momentum variation on the final energy gained by electron is lower in comparison with the effect of injection angle variation. It is observed when the injection angle is increased, the electron can stay more in acceleration phase and reach to more final energy. The maximum final energy of accelerated electron is about 2.5 GeV when the magnetic field is applied along the reverse direction. Also, the electron energy is increased with the increase of injection angle and lowest energy is related to the case of magnetic field applied along the reverse direction.