Characterization of the rod-pinch diode at 1 MV as a radiography source

The rod-pinch diode (RPD) is a kind of new X-ray source for flash radiographic applications, especially in the small-scale hydrodynamic experiments. According to theoretical analysis and the generator parameters, the 1 MV rod pinch diode has been designed and studied experimentally. The dose is measured with thermo-luminescent detectors through aluminum hemispherical end-plate (1-cm thick) at 1 m from the rod tip. The size of the radiation source is determined by measuring its edge spread function. The angular distribution of radiation from rod-pinch diode is also examined with angular dose measurements. As results, 1.21 to 1.45 rad at 1 m in the forward direction (0°) are achieved in 18.1 to 27.5 ns FWHM pulses. The spot sizes are 0.9 to 1.1 mm (LANL definition) for 1-mm-diameter blunt tungsten rods and 0.8 mm for 1-mm-diameter tapered tungsten rods. Measured angular distributions indicate that the dose increases monotonically from 0° to 90° by a factor of 1.28 to 1.43 both for blunt and tapered rods and suggest that the radiation still exhibits anisotropy at 1 MV.