X-ray converters for electron accelerators are commonly employed to treat materials that are difficult to penetrate with electron beams. After target material and thickness were optimized using Monte Carlo code Geant4 simulation, the converter's conversion efficiency did not perform well. The initial electron loses a large amount of energy in the form of reflected electrons. A V-shaped conversion target is proposed to improve the utilization of the reflected electrons and hence the conversion efficiency, and the simulation results confirm the assumption. The higher the angle of the V-shaped target, the higher the optimal conversion efficiency of the X-rays. The conversion efficiency of the V-shaped tantalum target with an angle of 80° reaches 12.38% at an incident electron energy of 5 MeV, and 17.11% at an incident energy of 7.5 MeV. Additionally, the adverse implications of the large angular distribution of the V-shaped target are discussed.

X-ray converter, bremsstrahlung, conversion efficiency, angular distribution, Geant4