X-ray absorption and scattering issues for rod-pinch radiographic sources

During the past decade, the rod-pinch diode has been used extensively for high-brightness, megavolt X-ray radiography. Success of the rod pinch derives from its small radiographic spot size for a range of driving voltages and X-ray spectra. Here, we examine two experimentally observed and more subtle phenomena that may impact radiographic performance for some systems: flat-field nonuniformity in the image plane due to X-ray absorption in the rod, and weak, large-scale structures around radiographic features due to cathode-scattered X-rays. X-ray imaging data from Cygnus and HRS are analyzed by the ITS Monte Carlo codes to determine if these phenomena are significant for Cygnus.