Measurement of Linear-attenuation Coefficient of Body Source Using Non-collimated Point Source Transmission Approach

Linear-attenuation coefficient of body source is an important parameter for the calculation of the selfabsorption correction factor. In this work, the noncollimated point source transmission method was introduced for the determination of the linearattenuation coefficient of unknown body source. The point source was directly placed atop, or at certain distance above the source container. By the comparison of the simulated transmission ratio with the experimental results, the linearattenuation coefficient of this body source was deduced. The principle and calculation process were presented in detail in the text. To test this method, five different substances with different densities were chosen as test subjects, and noncollimated transmission experiments were conducted using three different point sources. It shows that the experimental results of this method agree well with the theoretical values given by the XCOM platform, and this method can provide the linearattenuation coefficients of body sources conveniently. This method avoids the need for collimator, and limitations posed by size and shape of detector and sample. It is simple and easy to be used in laboratories.