GAMOS/GEANT4 simulation and comparison study of X-ray narrow-spectrum series at the national Secondary Standard Dosimetry Laboratory of Morocco

Abstract

This study aimed to simulate the X-ray Irradiator narrow-spectrum series and compare the results with experimental and recommended values in ISO standards. X-Ray beam qualities of N-40 to N-300 were established experimentally at the national Secondary Standard Dosimetry Laboratory (SSDL) of Morocco in purpose of calibrating radiation protection- level. The variations between the first half-value layer (1st HVL) and the second (2nd HVL) for experimental were within 5%. Also, homogeneity coefficients h were mostly between 0.75 and 1 according to ISO. GAMOS Monte Carlo code was used to simulate the radiation quality of narrow-spectrum series between N-40 to N-150. All 1st HVL, 2nd HVL, and h simulation values were compare with experimental and ISO values. In MC codes and GAMOS, there is no direct way to generate the X-ray spectrum if we do not have details of the X-ray tube geometry, dimensions and materials. Therefore, Institute of Physics and Engineering in Medicine report number 78 was used to generate the X-ray spectrums in purpose to test this method accuracy. The simulation results for the 1st HVL and 2nd HVL showed a good agreement with experimental data and with ISO 4037–1:1996 given values. Also, the comparison results showed that most of the homogeneity coefficients are within the ISO standard range.