High-resolution x-ray radiography with Fresnel zone plates on the University of Rochester's OMEGA Laser Systems

Experiments performed at the Laboratory for Laser Energetics with a continuous-wave (cw) x-ray source and on the OMEGA and OMEGA EP Laser Systems [Boehly et al., Opt. Commun. 133, 495 (1997) and Waxer et al., Opt. Photonics News 16, 30 (2005)] have utilized a Fresnel zone plate (FZP) to obtain x-ray images with a spatial resolution as small as similar to 1.5 mu m. Such FZP images were obtained with a charge-coupled device or a framing camera at energies ranging from 4.5 keV to 6.7 keV using x-ray line emission from both the cw source and high-intensity, laser-beam-illuminated metal foils. In all cases, the resolution test results are determined from patterns and grids backlit by these sources. The resolutions obtained are shown to be due to a combination of the spectral content of the x-ray sources and detector resolution limited by the magnification of the images (14x to 22x). High-speed framing cameras were used to obtain FZP images with frame times as short as similar to 30 ps. Double-shell implosions on OMEGA were backlit by laser-irradiated Fe foils, thus obtaining a framing-camera-limited, FZP-image resolution of similar to 3 mu m-4 mu m.

Automated summary

Experiments using FZP lens achieved high spatial resolution X-ray images at different energy ranges, with resolution test conducted using backlit patterns and grids. High-speed framing cameras were crucial in obtaining high-resolution FZP images.