An optimal design of X-ray target for uniform X-ray emission from an electronic brachytherapy system

► A novel X-ray target design is proposed. ► The target consists of a truncated conical reflection-type target and a transmission-type hemispherical cap. ► This combinatorial target assembly can produce X-rays with a good spatial uniformity over the entire solid angles. We present a novel design of an X-ray target to deliver uniform dose from an electronic brachytherapy system (EBS). This design comprises of a combination of both the reflection- and transmission-type target geometries. Monte-Carlo simulation code MCNP5 has been employed for the calculation of angular distribution of the X-ray intensity produced from various morphologies of X-ray targets. The simulation results reveal that the combinatorial target-assembly is promising and effective in achieving uniformity of X-ray emission over the entire space of solid angle of 4 π in comparison to a transmission-type target that produces X-rays mainly in the forward direction and a reflection-type target that generates X-rays mostly in the backward direction. As a direct consequence of the uniformity of X-ray emission, the combinatorial target-assembly can impart a uniform dose distribution which makes it suitable as a target of an X-ray tube for EBS.