Determination of Optimum Thickness of Tantalum, Tungsten, and Lead as X-Rays Converter for 10 MeV Electron Beam Using MCNP

This research aims to determine the optimum thickness of tantalum, tungsten, and lead as a BXR converter at a 10 MeV high-energy electron. If the thickness is too thin, the conversion efficiency will be relatively low because the electron deceleration process by the atomic nucleus of the converter material is not yet maximized. An e-beam with a finite penetrating power is produced by the high-energy electron accelerator. The e-beam energy needs to be changed into bremsstrahlung x-rays using a converter to increase its penetration. This optimum thickness provides optimum energy conversion efficiency. The simulation with MCNPX software is used to determine the optimum thickness of each material. The electron source is modeled as a 120 cm by 10 cm flat plane at a distance of 1 mm from the converter with an energy of 10 MeV. The converter measures 160 cm by 24 cm and ranges in thickness from 1 to 7.5 mm. Two planar detectors are then placed 2 cm in front and behind the converter. The simulation results indicate that the optimal thicknesses for the tantalum, tungsten, and lead converters are 2.0 mm, 1.8 mm, and 2.8 mm, respectively. Furthermore, the maximum forward-scattered bremsstrahlung x-ray energies are 2.1137 MeV, 2.1287 MeV, and 2.1850 MeV, respectively, while the maximum conversion efficiencies are 21.137%, 21.287%, and 21.850%, respectively. These findings can serve as a reference when designing the converter for the 10 MeV high-energy electron accelerator. The results can be used as a reference in the design of the BXR converter for the 10 MeV high-energy electron accelerator.