CAJ | 학술논문

利用蒙特卡罗模拟程序 MCNP 研究了 NaI（Tl）探测器对海水中137 Cs、131 I 的比计数率响应情况；计算了 NaI（Tl）探测器对不同半径海水球体源中137 Cs 与131 I 的比计数率响应曲线；分析了探测器防水套筒、NaI（Tl）晶体尺寸与结构、射线能量等因素对比计数率响应的影响；拟合了3R3型、5R5型 NaI（Tl）探测器最大比计数率 y max及有效探测距离 D。防水套筒模型与裸晶体简化模型的计算结果对比表明，裸晶体模型会给计算带来明显的偏差，应在模型设计时，考虑探测器结构，构建更精确的模型。
이용몽특잡라모의정서 MCNP 연구료 NaI（Tl）탐측기대해수중137 Cs、131 I 적비계수솔향응정황；계산료 NaI（Tl）탐측기대불동반경해수구체원중137 Cs 여131 I 적비계수솔향응곡선；분석료탐측기방수투통、NaI（Tl）정체척촌여결구、사선능량등인소대비계수솔향응적영향；의합료3R3형、5R5형 NaI（Tl）탐측기최대비계수솔 y max급유효탐측거리 D。방수투통모형여라정체간화모형적계산결과대비표명，라정체모형회급계산대래명현적편차，응재모형설계시，고필탐측기결구，구건경정학적모형。
A NaI(Tl)detector with waterproof sleeve used for in-situ measurement of specif-ic activity of artificial radionuclides of 137 Cs and 131 I in seawater was modeled with MCNP, and the specific counting rate curves of the detector with and without waterproof sleeve were calculated with different source radii.The effects of the detector structure,the size of the NaI(Tl) crystal,and the γ-ray energy were investigated.The maximum specific counting rate and effective detection range were calculated and compared for the detectors of 3×3 in-ches and 5×5 inches with and without waterproof sleeve,and the results show that the sim-plified naked crystal model would bring more deviation from the true results.