Charged Particles Acceleration By A Linearly Polarized Electromagnetic Wave In A Plasma Medium

Since Rutherford used alpha particle rays to hit gold foil with natural radioactive elements in 1919, people had realized the artificial nuclear reactions for the first time in human history. They were aware that if they want to understand the microscopic mechanism of material further deeply, it is necessary to use higher-speed particles to bombard the nucleus. Thus the acceleration of charged particles causes the physicists’ extensive research and attention. In the paper, Acceleration of electrons or charged particles by a linearly polarized electromagnetic wave (LPEMW) propagating in a medium along an external magnetic field is theoretically studied. The main contents are as follows:Firstly, We have investigated three acceleration cases here:(1) the medium’s refractive index changes with location but the external magnetic field is constant; (2) the medium’s refractive index is constant but the external magnetic field increases with the distance in the wave propagation direction; and (3) both the medium’s refractive index and the external magnetic field change with the distance. The results are pointed out that the most efficient (i.e., at a fixed acceleration distance, obtaining the highest relativistic factor) electron acceleration by the LPEMW can be fulfilled at case (3).Secondly, we discuss charged particles’ going backward at the three cases, finding at case (3) that the drawback in the acceleration which appears at case (2) can be avoided or greatly reduced, which is very important for acceleration of a bunch of electrons or charged particles by LPEMW.Thirdly, We study the acceleration effect for the different initial velocity of charged particles at case (3) for charged particles acceleration by LPEMW. We find the value of the initial velocity of charged particles has no effect on acceleration almostly. At the same time, we analyze the initial phase of LPEMW on acceleration effect. It is believed that our results can be helpful in the design of a compact and efficient charged particle accelerator.