Improvement of the Spatial Resolution Performance of Miniaturized Streak Tube Using Dual-Focusing

In the context of imaging laser radar systems (ILRS), the miniaturized streak tube (MST) serves as a crucial ultrafast diagnostic equipment, enabling the acquisition of high-quality 3-D images. The evaluation of information acquisition largely hinges on the spatial resolution (SR) performance of the MST, making it a significant parameter of interest. To enhance the system's performance, the imaging system was designed using the dual-electrode electrostatic focusing (DEEF) technique. In this study, the relationship between the focusing electric field and imaging quality was analyzed, while the static and dynamic pattern was constructed by the CST software. To quantify the SR, the Rayleigh criterion (RC) was employed. Furthermore, the feasibility of a larger detection area and higher SR were investigated. The experimental findings revealed that the dual-focusing MST 120-mm-long has better performance, its detection area is <tex-math notation="LaTeX">Φ</tex-math> 30 mm, the deflection sensitivity is 15.05 mm/kV, and the static SR is approximately 41.84 lp/mm. Besides, the model of the voltage discrete port and the matching resistance were established, and the dynamic pattern was implemented by introducing the time-varying scanning ramp pulses. Remarkably, when the gradient of the slope pulse was 1.65 kV/ns, the dynamic SR was approximately 23.70 lp/mm, surpassing the performance of single-focusing techniques. The research conclusions not only verify the feasibility of the dual-focusing MST but also provide theoretical support to the design of the MST with high spatial performance. Furthermore, it also provides a reference method for studying the dynamic characteristics of MST by the CST.