Background The Single-Channel Electron Multiplier (CEM), as a high-gain electrovacuum device, is widely utilized in fields such as mass spectrometry and space exploration. Currently, domestically produced CEMs often face challenges including relatively low gain and inconsistent performance.

Purpose To address these issues, this study undertakes the development of high-gain CEMs through both simulation and experimental approaches.

Methods For the simulation, a three-dimensional model of the CEM was established using CST Studio Suite, incorporating the finite integration technique, the Monte Carlo method, and the Furman secondary electron emission model. This model systematically simulated the electron trajectories and multiplication processes within the channel.

Results The simulation results indicate that the electron multiplication characteristics of CEMs are significantly influenced by structural parameters and functional thin films. The optimal structural parameters were identified as a funnel diameter of 13 mm, a channel diameter of 1.2 mm, a straight-channel length of 14 mm, and a bending radius of 15.5 mm.Experimentally, the fabricated CEM channels exhibited consistent morphology with a low film roughness of approximately 0.65 nm, indicating good process consistency and high smoothness of the inner walls, which aligns well with the theoretical design. A comparison between two CEMs with different structural parameters revealed that the optimized structure achieved a nearly fivefold increase in gain under the same operating voltage. Furthermore, after depositing an approximately 5 nm thick Al₂O₃ functional film on the inner channel wall via atomic layer deposition, the gain of the CEM increased by approximately 20 times under the same voltage, underscoring the critical role of functional films with a high secondary electron emission coefficient in enhancing gain.

Conclusions Through theoretical simulation and performance optimization analysis, this study provides key parameter optimization guidelines and a technical foundation for the localized design of CEMs.