<title>X-ray/EUV/FUV calibration of photographic films for solar research</title>

Abstract

Film was chosen as the detector for the Multi-Spectral Solar Telescope Array (MSSTA), a sub-orbital solar observatory designed to operate over the entire soft x-ray, extreme ultraviolet (EUV), and far ultraviolet (FUV) spectral regime. In order to accurately calibrate the solar images obtained on the initial May 13, 1991 MSSTA flight, and to optimize the film loads for the diverse telescopes being developed for the MSSTA re-flight, we performed extensive calibrations at the NIST SURF II and the Stanford Synchrotron Radiation Laboratory synchrotrons. In addition to detailed studies of the MSSTA flight films (XUV-100 and 649), we also measured the performance characteristics of Kodak Technical Pan 2415 film, and the Agfa 10E56, 10E75 and Ilford HOTEC holographic emulsions. These measurements yielded valuable information concerning the soft x-ray/EUV/FUV response of the films and provided important insights into the physical properties of the films and their behavior after prolonged exposure to high vacuum.