Initial findings for paraxial diode shielding studies on RITS-3

Summary form only given. The paraxial diode has been identified as one of the potential candidates capable of reaching the short-term radiographic source requirement for the proposed Hydrodynamic Research Facility at AWE. The off axis dose produced in the AWE paraxial diode is partly attenuated by a local Tungsten shielding cone. Shielding requirements to minimise the off axis dose reaching detectors has been calculated for the paraxial diode at 14 MeV, which suggest a minimum areal mass of 350g/cm/sup 2/ (17 cm of Tungsten) is required. This thickness is required at all angles from the X-ray source outside of the main collimated beam. Clearly, it would be beneficial to place as much of the shielding as possible around the X-ray source. The simplest way to achieve this is to increase the angle of the shielding cone (45/spl deg/ for Mogul E), however, this is likely to alter the electric field distribution in the A-K region and possibly the electron beam trajectories at the anode foil plane. This paper describes the work carried out on RITS-3 to determine if increasing the diode shielding cone angle affects the performance of the diode.