电子束电流对介质切伦科夫脉塞色散关系的影响

Effect of beam current on dispersion relation of plasma-filled dielectric Cherenkov maser

采用等离子体流体理论,从线性扰动方程出发,研究了电子束电流大小对介质切伦科夫脉塞中束波相互作用色散关系的影响,得到了当等离子体返回电流能有效中和与不能有效中和电子束电流两种情形下色散关系和波的增长率,并讨论了电子束电流对束波相互作用色散关系和波增长率的影响。研究表明,等离子体返回电流能有效中和与不能有效中和电子束电流两种情况下有着不同的色散关系和波的增长率。在波导参数和背景等离子体参数固定的情况下,电子束电流并不是越大越好,电子束电流过大不利于提高器件效率,它们之间存在最佳匹配关系。

Using plasma fluid theory,from linear perturbation equations,the effect of the beam current size on the dispersion relation of plasma-filled dielectric Cherenkov maser is examined when the beam current is complete,or not effectively neutralized by the return current in the background plasma.The dispersion relation and the wave growth of the TM0n are solved under both cases.Based on this,a discussion on the effect of the beam current on the dispersion relation and wave growth is given.Both of the cases of plasma return current can or not effectively neutralized electron beam＇s current has different dispersion relation and wave growth.When the parameters of waveguide and plasma are fixed,the electron beam current is not the bigger the better,too large electron beam current is harmful for improving the efficiency of the device,and there has an optimal matching relationship between them.