利用线性场理论和螺旋线的导电面模型 ,推导了在强引导磁场下 ,等离子体加载螺旋线慢波结构的色散关系 .数值计算了在不同的等离子体填充密度与填充半径条件下 ,螺旋线的色散特性、耦合阻抗和行波管的小信号增益 .研究发现 ,在螺旋线中填充了等离子体以后 ,形成了一种新的混合模式 ,螺旋线的色散特性与耦合阻抗都发生了很大的变化 ,行波管的增益得到显著提高 Based on the linear field theory and the conductive surface model of the helix, the dispersion relationship of the helical slow-wave plasma with helical loading under strong guidance magnetic field is deduced. Under different plasma filling density and filling radius, , The coupling impedance and the small-signal gain of the traveling-wave tube.The results show that after the plasma is filled in the helix, a new hybrid mode is formed, in which both the dispersion characteristic and the coupling impedance of the helix have been greatly increased The change of traveling wave tube gain has been significantly improved