就地γ谱仪峰谷比法测量<sup>137</sup>Cs深度分布

就地γ谱仪峰谷比法测量¹³⁷Cs深度分布

摘要: 研究就地γ谱仪测量地表层¹³⁷Cs深度分布的峰谷比法，建立了就地γ能谱峰谷比数值计算公式和实验剥谱方法。理论计算表明，峰谷比随¹³⁷Cs张弛深度的变化十分灵敏，土壤密度误差对峰谷比有一定影响，但变化不大时，对峰谷比法结果影响可忽略。野外验证实验显示，峰谷比法相对于样品实验室分析结果的最大相对偏差为31%，表明峰谷比法是可行的，所建立数值计算公式、实验剥谱方法是正确的。

Abstract: The peak-to-valley ratio (PVR) method was approached to determine the depth distribution of ¹³⁷Cs in soil by in-situ γ spectrometry. Theoretical calculations show that the variation of PVR is much sensitive with the dissimilarity of radioactive depth distribution, and the influence of soil density uncertainty to PVR is slight and can be neglected when the variation of soil density is within 10%. Field experiments were performed to justify the theories as correctness. The results show that the maximum relative deviation of in-situ γ spectrometry is about 31% relative to the samples analysis in laboratory, which indicates that PVR method of in-situ γ spectrometry is correct for the determination of radioactive depth distribution in soil.