MC simulation for measuring grease stain thickness in pipelines using scattering method

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. (authors)