ESTIMATION OF NEUTRON SCATTER CORRECTION FOR CALIBRATION OF PERSONNEL DOSIMETER AND DOSERATEMETER AGAINST 241Am–Be SOURCE—MONTE CARLO SIMULATION AND MEASUREMENTS

Neutron scatter contributions as a function of distance along the transverse axis of 241Am-Be source were estimated by three different methods such as shadow cone, semi-empirical and Monte Carlo. The Monte Carlo-based FLUKA code was used to simulate the existing room used for the calibration of CR-39 detector as well as LB6411 doseratemeter for selected distances from 241Am-Be source. The modified 241Am-Be spectra at different irradiation geometries such as at different source detector distances, behind the shadow cone, at the surface of the water phantom were also evaluated using Monte Carlo calculations. Neutron scatter contributions, estimated using three different methods compare reasonably well. It is proposed to use the scattering correction factors estimated through Monte Carlo simulation and other methods for the calibration of CR-39 detector and doseratemeter at 0.75 and 1 m distance from the source.