Streak cameras for soft X-ray and optical radiation

The need for a precise temporal correlation between x rays and optical signals appeared very early in the laser fusion program. One important problem was the timing of fast electrons preheating the fuel. The obvious time reference was the laser pulse, and the fast electrons were detected by the emission of hard x rays. In principle, both the laser pulse and hard x rays could be measured with two streak cameras, but the information cannot be correlated within few tens of picoseconds unless the two records are obtained from a single streak camera. The first hybrid camera was the OX-1 camera (Optical X-ray), implemented with an optical, sealed tube with a S-1 photocathode sensitive to the 1.06-μm wavelength of the Shiva Laser. An S-1 photocathode is sensitive to x rays. The RCA image converter tube has a 3-mm window of 7056 Corning glass reducing the transmission of x rays at energies below 30 keV. The calculated response of the image converter tube is presented. The Ox-1 was implemented to record four channels: Laser pulse fiducial; Scattered light from the target; Hard x rays from the target; Background