Design and Verification of 1-D Electron Beam Array Focusing System for Planar Integrated Traveling Wave Tube

This article presents a comprehensive validation study on the efficacy of the planar-integrated periodic permanent magnetic (PIPPM) focusing system, employing a specially designed and fabricated two-channel beamstick to assess its performance in 1-D electron beam array transport. This study centers on two PIPPM stacks: magnetic strips and magnetic rings. The analysis proves that the two-channel beamstick utilizing the planar magnet configuration with magnetic strips falls short in addressing material nonuniformity, leading to a deficiency in the adjustment mechanism for electron beam transport and an unsatisfactory transmission rate. In light of these challenges, the study proposes an alternative approach utilizing magnetic rings, with a detailed analysis of their magnetic properties. The experimental results demonstrate that the beam transmission rates in the two channels, measured at 116 mm, exceed expectations at 86.5% and 87.4%, respectively. These outcomes substantiate the rationality and effectiveness of the PIPPM design and introduce an innovative solution for advancing research in four-beam integrated traveling wave tubes (TWTs).