Point projection radiography with the flexible x-ray integer

Radiography techniques utilizing large-area x-ray sources (typically less than or equal to 7 keV) and pinhole-imaging gated x-ray diagnostics have long been used at the Nova laser facility. However, for targets requiring higher-energy x-ray backlighters (>9 keV), low conversion efficiencies and pinhole losses combine to make this scheme unworkable. The technique of point projection radiography has been improved upon to make imaging at high x-ray energies feasible. In this scheme a ''point'' source of x-rays, usually a small diameter (less than or equal to 25 mu m) fiber is illuminated with a single, 100-ps pulse from the Nova laser. A gated x-ray imager with a 500-ps electronic gate width is used to record the projected image. [K. S. Budil et al., Rev. Sci. Instrum. 67, 485 (1996).] The experimental challenges this technique presents and experimental results will be discussed. (C) 1997 American Institute of Physics.