An optimization of the relationship between crystal volume and MDAC

The volume and exposure time of nuclear radiation detectors are different in the Marine environment. This paper selects γ-rays emitted by ¹³¹I, ¹³⁷Cs and ²⁰⁸Tl radionuclides, and uses NaI detectors of different volumes to simulate the minimum detectable activity concentration (MDAC) at different exposure time. And this paper studies the relationship between the increase multiple of crystal volume and the decrease multiple of MDAC. In this paper, based on MDAC, the existence of nuclides at different crystal volumes and different exposure times was qualitatively calculated and analyzed, which will be of guiding significance to the in situ γ spectrum measurement and long-term monitoring of seawater.