Quantitative intensity measurements using a soft X-ray streak camera

A soft X-ray streak camera (SXRSC) has been calibrated in order to make absolute flux measurements of X-rays emitted from laser-produced plasmas. The SXRSC developed at the Lawrence Livermore National Laboratory and described in a companion paper in this issue is used to time-resolve X-ray pulses to better than 20 ps. The SXRSC uses an Au photocathode on a thin carbon substrate which is sensitive to X-rays from 100 eV to greater than 10 keV. Calibrations are done in the dynamic mode using a small laser-produced X-ray source. The SXRSC is calibrated by comparing its integrated signal to the output of calibrated X-ray diodes monitoring the source strength. Details of the experiment along with data from a typical calibration are presented. The measured SXRSC intensity response is linear over greater than two orders of magnitude. Using these calibrations, absolute intensities can be measured to an accuracy of ± 30 percent. An example of its use as a flux monitoring device is presented.