Intense beam-target interactions in linear induction accelerator radiography systems

Summary form only given. Modern flash X-ray systems employing electron linear induction accelerators require focal spot sizes of order 1 mm diameter incident on high-Z Bremsstrahlung targets. Typical beam parameters are in the range of several kiloamperes, tens of MeV with pulse lengths of order 50 ns. A single pulse with these parameters is so intense that it converts the target material into a hot plasma with velocities on the order of several centimeters per microsecond. Intense axial electric fields will exist on the target surface which may lead to the extraction of light contaminant ions. These ions can travel upstream where they will act as an electrostatic lens which can cause a time varying disruption of the focal spot. Experimental and theoretical work on this backstreaming ion mechanism will be presented along with issues for multiple pulse operation.