Photodiodes with x-ray sensitive photocathodes are commonly used as broadband x-ray detectors in fusion plasma diagnostics. We have measured the photocathode quantum efficiency between 1–500 Å of common photocathode materials including aluminum, copper, nickel, gold, three forms of carbon, chromium, and cesium iodide. We have also studied the effects of the experimental environment and long-term cathode aging on the measured quantum efficiencies. In addition, we have measured the x-ray mass-absorption coefficients of x-ray filter windows of Kimfoil, aluminum, polypropylene, and Formvar in energy regions where data were previously unavailable. Measurements between 1–50 Å were performed at the Los Alamos Scientific Laboratory’s low-energy x-ray calibration facility, while the measurements between 50–500 Å were performed at the National Bureau of Standard’s synchrotron ultraviolet radiation facility.

To investigate the uniformity of compression of spherical targets irradiated with high-energy CO(2) lasers, an array of pinhole cameras has been set up to obtain 2-D views from four different directions. To reconstruct the 3-D source we have devised a computer code based on a maximum entropy algorithm. With synthetic input data the code gives acceptable reconstructions provided the source is smooth and has a simple shape. We present a set of serial slices through the reconstructed x-ray emission distribution in a glass microsphere imploded with the LASL two-beam CO(2) laser.