Different effective dose conversion coefficients for monoenergetic neutron fluence from 10-9 MeV to 20 MeV – A methodological comparative study

H. Miri H.a1, L. Rafat M.a1 and K. Karimi S.a1 c1

a1 Physics department, school of sciences, Ferdowsi University of Mashhad, Iran


Calculations are presented of the effective doses per unit neutron fluence according to the ICRP publications 60 and 103. Monte Carlo N-Particle (MCNPX) code was used for six geometrical conditions of irradiation (Anterior-Posterior, Posterior-Anterior, Left-Lateral, Right-Lateral, Rotation and Isotropic) on Oak Ridge National Laboratory (ORNL) modified mathematical adult phantoms for monoenergetic neutrons from 10-9 MeV to 20 MeV. The conversion coefficients were compared with the results of an analytical phantom (Medical Internal Radiation Dose (MIRD-5)) and some voxel model (ICRP/ICRU Reference Voxel Phantom (ICRP/ICRU RVP), HANAKO, TARO and Visible Human Project (VIPMAN)). From these comparisons, one can conclude that large discrepancies between data sets appear when wR and different sizes of the phantoms have been used for calculations. Furthermore, the differences in applied Monte Carlo codes or simulated body models could make some discrepancies less than 15%.

(Received September 28 2011)

(Accepted February 19 2012)

(Online publication July 04 2012)

Key Words:

  • Neutron effective dose;
  • ORNL modified phantom;
  • Monte Carlo codes;
  • conversion coefficients


c1 Corresponding author: