Measurement of the average path length of gamma-rays in samples using scattered radiation

A method for measuring the average path length traversed by gamma-rays in a sample is presented. In this method the amount of radiation scattered within the sample at small angles and registered in the spectrum is measured. It is shown that the increase in counts in an energy interval close to the energy of the emitted gamma-rays, relative to the value attained in the absence of the interaction between the gamma-rays and the sample, is proportional to the average path length in the sample. Measurements of the average path length in samples of cylindrical geometry with various dimensions and at several energies are presented and compared with the predicted values. The differences between the measured and predicted values are discussed.