OBJECTIVE: In this work, we evaluate the capabilities of a very compact fast plastic scintillator with an optical fiber readout by a SiPM and electronics sensor which has been used to provide information on the time structure at the nanosecond level of a clinical proton beam.
METHODS: A 3 × 3 × 3 mm3 plastic scintillator (EJ-232Q Eljen Technology) coupled to a 3 × 3 mm2 SiPM (MicroFJ-SMA-30035, Onsemi) has been characterized with a 70 MeV clinical proton beam accelerated in a Proteus One synchrocyclotron. The signal was read out by a high sampling rate oscilloscope (5 GS/s). By exposing the sensor directly to the proton beam, the time beam profile of individual spots was recorded.
RESULTS: Measurements of detector signal have been obtained with a time sampling period of 0.8 ns. Proton bunch period (16 ns), spot (10 μs) and interspot (1 ms) time structures could be observed in the time profile of the detector signal amplitude. From this, the RF frequency of the accelerator has been extracted, which is found to be 64 MHz.
CONCLUSIONS: The proposed system was able to measure the fine time structure of a clinical proton accelerator online and with ns time resolution.
目的:在这项工作中,
方法:耦合到3×3mm2SiPM(MicroFJ-SMA-30035,Onsemi)的3×3×3×3mm3塑料闪烁体(EJ-232QEljenTechnology)的特征是在ProteusOne同步回旋加速器中加速了70MeV临床质子束。
结果:以0.8ns的时间采样周期获得检测器信号的测量值。
结论:所提出的系统能够在线测量临床质子加速器的精细时间结构,并具有ns时间分辨率。