The implementation of rod pinch diodes on negative polarity pulse power machines

Summary form only given, as follows. With the increase in popularity of the rod pinch diode X-ray source being fielded by the US for several radiographic experiments, it was decided to look at this diode configuration on some available UK machines. The rod pinch diode may be able to complement the well established self magnetically pinched diode and the paraxial diode currently used on the UK pulse power machines used for radiography. The rod pinch diode works at currents similar to the self magnetic pinch and could be fielded on some of the UK machines without modifying their output parameters. All the UK radiographic machines operate in negative polarity and cannot readily be switched to positive. This has consequences for electron trajectories, potential loss current paths and X-ray photon attenuation by the anode support structure. This poster explains the problems faced and looks at the way the diode is fielded and operated on machines with output voltages ranging from 800 kV to nearly 6 MV.