分类: 物理学 >> 核物理学 提交时间: 2023-07-12
摘要: To guarantee the exact proton dose applied to patients and ensure treatment safety while disrupting and destroying tumor cells, it is essential to accurately monitor the proton beam current in real-time during patient treatment. Because clinical treatment requires a proton beam current in the ~nA range, nondestructive beam current monitors (BCMs) are preferred to minimize the degradation of beam quality. However, this poses significant challenges in accurately monitoring such extremely low beam intensities. This study proposes a cavity-type BCM equipped with a dielectric plate to reduce its dimensions and achieve sufficient measurement sensitivity for practical requirements. A prototype cavity BCM was fabricated, and offline testing was performed using a metal wire to simulate the beam to study its performance. Both the simulation and experimental results showed that the cavity BCM could measure ultralow proton beam currents with a resolution up to 0.03 nA.