摘要 : In this paper we review the primary factors that affect the timing precision of a scintillation detector. Monte Carlo calculations were performed to explore the dependence of the timing precision on the number of photoelectrons, t... 展开 In this paper we review the primary factors that affect the timing precision of a scintillation detector. Monte Carlo calculations were performed to explore the dependence of the timing precision on the number of photoelectrons, the scintillator decay and rise times, the depth of interaction uncertainty, the time dispersion of the optical photons (modeled as an exponential decay), the photodetector rise time and transit time jitter, the leading-edge trigger level, and electronic noise. The Monte Carlo code was used to estimate the practical limits on the timing precision for an energy deposition of 511keV in 3mm×3mm×30mm Lu2SiO5:Ce and LaBr3:Ce crystals. The calculated timing precisions are consistent with the best experimental literature values. We then calculated the timing precision for 820 cases that sampled scintillator rise times from 0 to 1.0ns, photon dispersion times from 0 to 0.2ns, photodetector time jitters from 0 to 0.5ns fwhm, and A from 10 to 10 000 photoelectrons per ns decay time. Since the timing precision R was found to depend on A-1/2more than any other factor, we tabulated the parameter B, where R = BA-1/2. An empirical analytical formula was found that fit the tabulated values of B with an rms deviation of 2.2% of the value of B. The theoretical lower bound of the timing precision was calculated for the example of 0.5ns rise time, 0.1ns photon dispersion, and 0.2ns fwhm photodetector time jitter. The lower bound was at most 15% lower than leading-edge timing discrimination for A from 10 to 10 000 photoelectrons ns-1. A timing precision of 8ps fwhm should be possible for an energy deposition of 511keV using currently available photodetectors if a theoretically possible scintillator were developed that could produce 10 000 photoelectrons ns-1. 收起