X-ray imaging of high velocity moving objects by scanning summation using a single photon processing system

X-ray imaging has been used extensively in the manufacturing industry. In the paper and paperboard industry X-ray imaging has been used for measuring parameters such as coat weight, using mean values of X-ray absorption inline in the manufacturing machines. Recently, an interest has surfaced to image paperboard coating with pixel resolved images showing material distribution in the coating on the paperboard, and to do this inline in the paper machine. Naturally, imaging with pixel resolution in an application where the paperboard web travels with velocities in the order of 10 m/s sets harsh demands on the X-ray source and the detector system to be used. This paper presents a scanning imaging method for single photon imaging systems that lower the demands on the source flux by hundreds of times, enabling a system to be developed for high velocity industrial measurement applications. The paper presents the imaging method, a discussion of system limitations, simulations and real measurements in a laboratory environment with a moving test object of low velocity, all to verify the potential and limits of the proposed method.