Study on spectral response and effective center of NaI(TI) detectors in different size

In this paper, we investigate the effects of scintillation detector in different sizes to the peak efficiency, energy spectrum response and effective center of γ-rays in different energy using three types of point-ray sources ¹³⁷Cs, ⁶⁰Co and ²²Na. The experimental results show that peak position and energy resolution of photoelectric peaks of γ energy spectra in different energy are changed by the different sizes of scintillating crystals. It is also found that the position of the effective center depends on the size of the scintillation crystal, The reciprocal of the peak efficiency is inversely proportional to the square of the effective distance of the detector. The experimental results can also provide references for improving energy spectrum response and high-precision measurement of scintillation detector NaI(Tl) in different sizes. (authors)