Abstract

In our world, nuclear accident is unavoidable. This means that we are under radiation risk all the time. Therefore, you should determine the ionized atoms (absorbed dose) punctually and as fast as possible to deal properly with victims in the triage process. The present study attempts to determine the absorbed dose generated in femur bone that utilized femur phantom (Health Physics Society N13.32) after different energy levels (30 keV to 10 MeV) relying on the numerical simulation of Monte Carlo N-Particle (MCNP)-5. The results showed the gradual reduction of Kerma air free values with the increase of energy from 30 to 100 keV, after a dramatic increase was noticed up to 10 MeV. The behaviour of the conversion factor illustrated the inverse relation with increment of energy. The first value was obtained at 30 keV (0.0368 Gy/Gy) and remarkable decrease was observed up to 150 keV (0.0245 Gy/Gy). The conversion factor remains almost constant between 200 and 800 keV and dramatic depression specified the higher energies. Further work suggestion is to estimate the conversion factors with plastic buttons and ribs bone or mediastinum, and between eye glasses with orbital tissue.

Key words: Absorbed dose, dose conversion, Kerma free air, mass absorption coefficient, Monte Carlo simulation, radiation accident.