A study of thickness and penetration depth dependence of specific absorbed fraction of energy in bone

Highlights: → Energy absorption build-up factor of Bone has been computed for wide energy range (0.015 MeV-15 MeV). → The computed absorption build-up factor is used to estimate specific absorbed fraction of energy (φ). → The dependence of φ on incident photon energy and penetration depth of the medium has been studied. → The computed φ values are more accurate than the data available in the literature. → The application of the present work is also discussed. - Abstract: G-P fitting method has been used to compute energy absorption build-up factor of bone compact and bone cortical for wide energy range (0.015-15 MeV). The computed absorption build-up factor is used to estimate specific absorbed fraction of energy. The thickness of the medium up to 10 mm and with penetration depth up to 40 mean free paths considered. The dependence of specific absorbed fraction of energy on incident photon energy, penetration and the thickness of the medium have also been studied. The variations of specific absorbed fraction of energy with incident photon energy, penetration and the thickness of the medium are shown in graphs. The computed specific absorbed fractions of energy values are more accurate than the data available in the literature because the variation of an effective atomic number with energy is also considered in the calculation. The application of the present work is also discussed.