POINT PROJECTION RADIOGRAPHY WITH THE FLEXIBLE X-RAY INTEGER

Radiography techniques utilizing large-area x-ray sources (typically l ess than or equal to 7 keV) and pinhole-imaging gated x-ray diagnostic s have long been used at the Nova laser facility. However, for targets requiring higher-energy x-ray backlighters (>9 keV), low conversion e fficiencies 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 ''po int'' source of x-rays, usually a small diameter (less than or equal t o 25 mu m) fiber is illuminated with a single, 100-ps pulse from the N ova 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. In strum. 67, 485 (1996).] The experimental challenges this technique pre sents and experimental results will be discussed. (C) 1997 American In stitute of Physics.