中文摘要：

用铁板模拟管壁，进行实际油垢的小角度散射测厚实验，并用MCNP程序在与实际实验相同的几何条件下进行模拟运算，来观察在不同的小角度散射情况下，散射计数与油垢厚度之间的关系。结果表明：实验与模拟结果符合良好，特别是在45°入射情况下，实验和模拟结果中的R2基本上大于0．99，表明45°入射角对于垢厚和散射光子数之间的线性关系是个较好的选择。小角度法测垢是可行的。

英文摘要：

By iron bar presenting oil tube, making acute angle scattering experiment on measuring grease stain by using oil crust, and a MCNP simulation of the experiment was made in the same geometrical con- dition to observe the relationship between scattering photon numbers and grease stain thickness. The re- sult shows that experiment and simulation result fits very well. Especially for 45 incident angle the value of R2 is, on the whole, bigger than 0.99, means that 45 incident angle is a good choice for the linear rela- tionship between scattering photon numbers and grease stain thickness. Acute angle scattering is feasible.