LAUSR

Microwave pulse propagation through a rapidly created plasma and frequency up-conversion has been demonstrated by the particle-in-cell (PIC) method. Compared with the finite-difference time-domain method in which the time-varying plasma is simplified as a dielectric medium, the PIC method considering the interaction and motion of charged particles would be much closer to the experimental values. It is found that the source wave amplitude has a stable range to obtain the stable output. If the source wave amplitude is below 103 V/m with the plasma density of 4×1019m−3, the output is mainly the plasma noise. Moreover, the higher amplitude source wave beyond 108 V/m would break the spatial distribution of the plasma so as to have an influence on the conversion efficiency. The stable range of source wave amplitude is affected by the plasma density. The power loss will increase with the increase in the plasma density in the PIC method, and it is more convenient and accurate to discuss the effects of the collisi...