Design of high gain discrete dynode electron multiplier

Abstract This study focuses on the optimization of discrete dynode electron multipliers (DEMs), which are critical for high-sensitivity signal detection in applications such as particle physics, nuclear reaction monitoring, and medical imaging. The research employs CST Studio Suite® electromagnetic simulations to analyze the impact of structural parameters — such as inter-dynode voltages, incidence angles, and surface coatings — on electron trajectory dynamics and multiplication efficiency. A 26-stage MgO dynode array is simulated, featuring dual output modes (analog and pulse counting) to accommodate varying ion input densities. The optimization process identifies key geometric parameters, including dynode spacing, curvature, and alignment, that significantly influence gain performance. The optimized design achieves a simulated gain of 1.8×10 5 in analog mode and 5.5×10 7 in pulse-counting mode, representing substantial improvements over baseline configurations. Experimental validation confirms the simulation trends, though discrepancies due to material degradation during assembly are noted. This work provides actionable insights for the design and optimization of high-performance DEMs, addressing challenges in achieving stable, high-gain operation over extended periods.