X-Ray Imaging with Compact Kirkpatrick-Baez Microscopes

X-ray imaging is needed to diagnose inertial confinement fusion (ICF) implosions. For example, radiography using an x-ray backlighter target allows the size, symmetry, and density of both the compressed core and surrounding shell to be determined. One means of imaging ICF target x-ray emission is a compact Kirkpatrick-Baez (KB) microscope. Before a KB microscope is used, the KB optic must have its best focus location and resolution determined. Test exposures were taken with an electron-beam-generated x-ray source. The test target was a copper grid with 25.4 μm diameter wires and a reference hole to align different exposures. A PV-Wave program was written to efficiently take lineouts across the image. These lineouts graph the film density of the shadows created by the mesh grid. Measurements of the edge response of the shadows were subsequently used to determine the best focus positions in the images, as well as the point spread function near best focus. The calibrated mirror pairs will assist the continued development of a 16-image KB microscope.