Design and Analysis of Electron Beam of 0.67 THz Traveling Wave Tube

The performance of the electron beam will greatly affect the performance of the traveling wave tube (TWT). The electron gun and focusing system (EGFS) are key parts of TWT, which complete the electron beam's generation, shaping, focusing, and transmission. The EGFS of 0.67 THz TWT is simulated and analyzed in this article. First, the initial parameters of the electron gun were obtained using the Tiwary method and MATLAB. After further simulation and debugging, the circular electron beam electron gun was designed with an operating voltage of 23.8 kV and a current of 18 mA; the filling ratio at the waist is only 50%. Second, to ensure the electron beam's stable transmission and reduce the device's size and weight, the periodic closed magnetic (PCM) focusing structure matching the electron gun was adopted, making the stable transmission distance of the electron beam greater than 30 mm, and it has good laminar flow. Finally, the sensitivity and thermal effect analyses were carried out to make the designed EGFS meet the processing requirements.