有限尺寸宏粒子空间电荷场研究

Study on finite-size macro particles space-charge fields

用格林函数理论导出了圆柱对称系统中有限尺寸宏粒子一维和二维空间电荷场权函数的表达式 ,比较了有限尺寸宏粒子空间电荷场权函数与圆盘或圆环模型空间电荷场权函数的差别 ,得到了与圆盘或圆环模型空间电荷场权函数[1] 不同的、更合理的计算结果。并用这两种空间电荷场权函数模拟了螺旋线行波管中的注波互作用过程 ,得到了其输出功率曲线 ,表明了用有限尺寸宏粒子计算的互作用输出功率比圆盘或圆环模型计算的输出功率饱和位置提前 。

In this paper, the space-charge weight functions of 1D and 2D finite-size macro particles for cylindrical system are derived using Green's function. The difference between space-charge field weight functions using the model of finite-size macro particles and those using the model of disk or ring is compared, and the more reasonable computing results are acquired. The output power of beam-wave interaction in helix TWT has been computed and compared with these two kinds of functions. The calculated results show that the output power of the finite-size macro particle model saturated sooner with a higher value than the other model.