A simple numerical method for gamma-ray self-attenuation correction for samples of common geometries

A simple numerical approach has been used to calculate attenuation correction factors for homogeneous samples of cylindrical, box-shaped and spherical geometries. The method involves the generation of random points within the sample and on the detector surface. The attenuation correction factors are then calculated from the distance traveled by the gamma ray to reach the detector and its path length in the sample. The results have been compared with analytical expressions available in literature and also with the attenuation correction (katt) values calculated using Monte-Carlo N-Particle Transport Code (MCNP). The advantage of the approach is that it is common to all the geometries and is independent of any approximations regarding sample–detector geometry. This method is found to be applicable at all sample-to-detector distance, so that additional care to select a proper formula valid for particular sample–detector distance is eliminated.