Analysis of Transverse Magnetic Fields in Asymmetric PPM Focusing System for Coupled-Cavity TWTs

The internal magnetic fields of two asymmetric PPM focusing systems are simulated with 3D magnetic fields software in this paper.One of them,the coupling slot is arranged with 180,and another arranged in a line.Based on the results,we analyses the transverse magnetic fields of asymmetric PPM focusing systems and the reasons of the transverse magnetic fields in the two structures.The improved efficiency and magnetic saturation to asymmetric PPM focusing systems by adjusting the iron loading head are summarized.Finally,three different reasons of the transverse magnetic fields and the improved methods reducing the transverse magnetic fields of the two structures are presented.