Design and performance study of a dielectric-filled cavity beam current monitor for HUST-PTF

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 similar to 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 off-line 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.

Automated summary

To ensure the safety and effectiveness of proton therapy, it is necessary to accurately monitor the proton beam current in real-time during treatment. This study proposes a cavity-type beam current monitor (BCM) equipped with a dielectric plate to accurately measure ultra-low proton beam currents. Both simulation and experimental results demonstrate that the BCM has a resolution of up to 0.03 nA, making it suitable for practical applications.