Feasibility of efficient electron beam transmission in EB-pumped excimer diodes without guided fields

High-power excimer lasers, characterized by their short wavelength and excellent beam uniformity, represent potential drivers for inertial confinement fusion. Enhancing the electron beam transmission efficiency of these lasers is essential for improving their electro-optic conversion efficiency. Previously, the improvement of electron beam transmission efficiency relied on strong guiding magnetic fields, which, however, could not fully address energy losses of the electron beam on the grid and also affected the uniformity of energy deposition in the laser chamber behind the grid, thereby increasing the operational costs of the lasers. This paper proposes regulating the inward-pinching magnetic force and outward-diverging electric force during diode design to calculate the impact region of the electron beam on the anode. Based on this calculated region, the grid and anode are designed to allow most of the electron beam to bypass the grid and transmit through the anode membrane, potentially enhancing the electron beam transmission efficiency of the diode without the use of guiding magnetic fields. To this end, a feasibility analysis of improving electron beam transmission efficiency in diodes without guiding magnetic fields is conducted. Simulations of the electron beam and calculations of electron beam energy deposition indicate that similar electron beam deposition efficiency can be achieved without guiding magnetic fields compared to with them, suggesting the feasibility of enhancing electron beam transmission efficiency in diodes without guiding magnetic fields.