For designing a nondestructive detection system to measure grease stain thickness in pipelines by using γ-ray scattering method

Monte-Carlo simulations were carried out for a pipeline with and without thermal insulation layer(TIL).Response curves of the scattered γ-ray counts from the grease stain thicknesses(d) were obtained

under different source-pipe distances(t) and source-detector distances(h).It was found that the count varied with d in exponential curves.The maximum detectable thickness of the grease stain(dM) became larger with increasing t or h

and the dM with TIL was smaller than that without TIL.The results are of help for performing nondestructive measurement of the grease stain thickness in pipelines.