Shielding Calculation for 9MeV X-Ray Cargo Container Inspection System for Multi-View Image Acquisition using Monte Carlo Method

Abstract

The container inspection system is an equipment that inspects the inside of the container without opening the container using the X-ray. It has been mainly used for the smuggling of container cargo but recently it has been widely used to monitor terrorist material in order to prevent terrorism in the world. The inspection system using X-rays may not be accurate depending on the loading direction of the container cargo and the shape of the object. For example, in the case of a pipe-type object, it is not easy to identify an object because it is seen as a round object when the object is viewed in the straight-ahead direction. In order to compensate for this, two x-ray imaging systems(straight and orthogonal) areusually used for image acquisition. This method increases the number of systems and increases shielding, which adds a lot of cost to system construction. As an alternative to this, we are developing a multi-view image acquisition system for container inspection to acquire two images using one X-ray generator. This inspection system uses x-rays generated in a specific angular range rather than the commonly x-rays(fan beam type). Therefore, it is required to design a shieldingfacility suitable for multi - view image acquisition facilities. In this research, the approximate shielding thicknesses of the primary and secondary barriers were set by referring to NCRP 49 and NCRP 151. The optimal thicknesses of the pri