Quantitative calibration of X-ray film response in the 5-keV to 1.3-MeV region.

Response vs energy was measured for Kodak No-Screen and Rapid-Process films. Monochromatic incident radiation was obtained by fluorescent excitation of the characteristic x-ray lines in an element such as copper followed by crystal diffraction to pass only the Kalpha component. Fluorescing elements from atomic number 23(V) to 60(Nd) covered the energy range 4.95-37.0 keV. A single point at 1.25 MeV was obtained for gamma radiation from (60)Co. A proportional detector measured the incident flux density (photons cm(-2) sec(-1)). The No-Screen film is more sensitive than Rapid-Process film and has greater contrast. At 8 keV, to obtain a photographic density of unity requires 3.76 x 10(7) photons/cm(2) for No-Screen film and 4.19 x 10(7) photons/cm(2) for Rapid-Process film; at 20 keV, No-Screen film requires 7.47 x 10(7) photons/cm(2) and Rapid-Process film requires 12.87 x 10(7) photons/cm(2).