Performance of a plastic scintillation fiber dosimeter based on different photoelectric devices

The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal. Its features directly determine the overall performance of the dosimeter. For a plastic scintillation fiber dosimeter (PSFD) with a current readout mode, systematic studies of the stability and light-dose response were performed for the photomultiplier tube (PMT), silicon photomultiplier (SiPM), avalanche photodiode (APD), and photodiode (PD). The temperature stability, long-term stability, repeatability, signal-to-noise ratio (SNR), and current dose response of the PSFD with the abovementioned photoelectric devices were studied using a pulsed LED light source and the Small Animal Radiation Therapy platform. An exponential relationship between the dark/net current and temperature was obtained for all the devices. It is shown that the APD is the most sensitive device to temperature, with a current dependence on temperature reaching 6.5 $$\%\,^{\circ }\hbox {C}^{-1}$$ at room temperature, whereas for the other devices this dependence is always $$<{0.6}{\%\,^{\circ }\hbox {C}^{-1}}$$ . In terms of long-term stability, the net current of PD can change by up to 4% when working continuously for 8 h and 2% when working intermittently for 32 h, whereas for the other devices, the changes are all <1%. For the dose response, the PMT and SiPM exhibit excellent linear responses and SNRs within the range of 0.1–60 Gy/min. For the PSFD with a current readout mode, the performance of the PMT and SiPM is concluded to be better than that of the other devices in the study. In particular, the SiPM, which has a compact size, low bias voltage, and antimagnetic interference, has great advantages for further applications.