Experimental measurement of spatial position jitters of a high-energy radiographic source

In flash-radiography, scattering photons will decrease the definition of receiving images, which limits the resolving power of the interface and the density of the object for radiography. The anti-scatter grid camera is able to improve the picture resolving power due to a great reduction of scattering photons, which, in the meantime, demands a much more stable spatial position of the X-ray source in order to reduce the loss of signal photons in the anti-scatter grid structure. The pinhole imaging method is applied to measure the spatial distribution of the Dragon-I LIA X-ray source, by which the centroid and the FWHM of the spot can be calculated, and to analyze the influence of the electron beam focusing to the displacement and the size of the source spot. Experimental results demonstrate that a variation in electron beam focusing will lead to a distinct change of the spatial position and the size of the radiographic source. It can also be seen that the jitter of the source centroid and the change of the spot size can be kept in a small range when the focusing of the electron beam remains invariant.