Electron Acceleration By An Circularly Polarized Electromagnetic Wave

Using electromagnetic waves to accelerate charged particles is a good choice for a compact accelerator with small size and low-energy consumption to effectively accelerate the charged particle. This thesis research on using circularly polarized electromagnetic wave accelerated charged particles. In order to facilitate the calculation, select electronics as a representative of charged particles. The main content are as follows:First of all, we propose a new scheme for electrons or charged particles acceleration by a travelling circularly polarized electromagnetic wave (CPEMW) propagating along an external magnetic field in a medium with a tapered refractive index. Previous theoretical results show that an efficient electron acceleration by the CPEMW can be fulfilled through either (1) decreasing the refractive index (under a constant external magnetic field condition) or (2) increasing the external magnetic field (under a constant refractive index condition) along the longitudinal distance.Secondly, through numerical simulation, this thesis finds that the combination of these two cases (i.e., the refractive index decreases and the external magnetic field increases with the distance simultaneously) can allow for acceleration effect superior to that when either of the two schemes works alone. Meanwhile, the new scheme can effectively control the cyclotron radius does not monotonically increasing. More important, the new scheme can avoid or greatly reduce the drawback of electrons' flying backward during the acceleration time, which is very helpful in designing compact and efficient low-energy charged particles accelerators. Results show that when the electric field intensity is 1.20×108V/m, by selecting the appropriate parameters the respectively factor can get 25.75 at z=0.1m. Which is higher than 18.87 (scheme 1) and 20.86 (scheme 2) under the same conditions. In addition, we consider the effect of the initial velocity or inject with a small angel on electron acceleration.Thirdly, this thesis establish a theoretical model, which is easy to achieve in the experiment. The electromagnetic surface waves mimicking Spoof Surface-Plasmons (SSP) can be sustained by a metal whose surface is periodically corrugated. The different metal structures of one-dimensional array of grooves can allow different propagation constants. The electron or charged particle can be efficiently accelerated by controlling the groove structure to realize manipulating the phase velocity of SSP mode.We hope that our research can be helpful in designing an efficient and compact charged particle acceleration device or electron beam accelerator.