  In high-energy flash radiography, scattered photons will degrade the
acquiring image, which limits the resolving power of the interface and density
of the dense object. The application of large anti-scatter grid is capable of
remarkably decreasing scattered photons, whereas requires a very stable source
position in order to reduce the loss of signal photons in the grid structure.
The pinhole imaging technique is applied to observe spatial jitters of a
triple-pulse radiographic source produced by a linear induction accelerator.
Numerical simulations are taken to analyze the performance of the imaging
technique with same or close parameters of the pinhole object and experimental
alignment Experiments are carried out to observe spatial jitters of the source
between different measurements. Deviations of the source position between
different pulses are also measured in each experiment.
