Photon mass attenuation coefficients of importance to dosimetry

For Medical imaging and radiation therapy applications photon, of energies less than 1.3 MeV, are commonly utilized. The importance of the data of attenuation coefficients for this energy range cannot be overemphasized. In the past, there were many measurements made using multiple sources and low-resolution scintillation detectors. The XCOM database from NIST, based on detailed model calculations, is the most commonly used reference. Our goal is to provide an experimental verification of the database and compare with the earlier measurements for photon energies of interest for medical and environmental considerations. Here, we report our first measurements with water.