Modeling of a gridded electron gun for traveling wave tubes

The EGUN code is used to model a 0,7 ¿Perv electron gun with control and shadow grids under space-charge limited flow. The model parameters will be used to implement a pulsed traveling-wave tube (TWT). The simulation main goal is to obtain an electron gun to yield a 2.0 mm beam-waist with a 6.5 compression ratio. This work presents the sensitivity analysis for the following input geometric quantities: the cathode radius disc; the electrode focus angle; the cathode-to-anode distance; the grid-to-cathode distance; and the grid voltage. It was observed a decreasing of the gun perveance and the current when the grid voltage was turned on if it compared to the gun design without grids. The results also show that a shadow-grid physically modeled that led to a gun with lower current/perveance. Moreover, a 3-dimensional (3D) viewer of the EGUN output current density data is implemented. Last, a final assembling stage electron gun experimental setup is presented.