Image blur in high energy electron radiography

High energy electron radiography(eRad) can quantitatively measure target material and its internal structure without taking target apart, it is a new NDT (nondestructive testing) technique. Compared with high energy proton radiography, eRad has submicron resolution and promises to be a powerful tool for mesoscale diagnosis. Its image blur is a crucial point that needs to be deeply studied. To study the influence of interaction and imaging beamline on image blur, numerical simulation using the Monte Carlo code Geant4 has been implemented, including the entire physics process of 12 GeV electron beam travelling through the object and beamline and arriving at the image plane. This article mainly analyzes the chromatic aberration of the imaging beamline, the blur of the longitudinal length of target and the influence of secondary particles using this model. The result shows that the scale of image blur in eRad is just submicron and most blur is caused by imaging beamline, the influence of longitudinal length of target and secondly particle can be neglected.