本工作采用石蜡模拟油垢,用~(60)Co放射源平均能量1.25 MeV的γ射线小角度入射,分别在小角度和大角度散射角内接收散射γ射线。结果显示,散射γ计数与被测石蜡厚度之间存在线性关系,而且小角度散射法测量结果比大角度散射法所测结果更好。 In this work, paraffin wax was used to simulate the grease stain, and was incident on a γ-ray with an average energy of 1.25 MeV from a ~ (60) Co radioactive source. The scattered γ-rays were received at small and large scattering angles. The results show that there is a linear relationship between the scattering γ count and the measured paraffin thickness, and the results obtained by the small-angle scattering method are better than those obtained by the high-angle scattering method.