Relative efficiencies of energy to photographic density conversions in typical screen-film systems

This study compared the speeds of six typical screen-film systems and the energy absorbed by their screen pairs as a function of incident x-ray energy. Three of the screen-film systems studied had calcium fungstate phosphors, one contained barium strontium sulfate, and two were composed of a mixture of lanthanum oxysulfide with larger amounts of gadolinium oxysulfide. A source of monoenergetic radiation was used for measurement of the relationship between these two quantities as a function of keV. With certain exceptions, the speeds of screen-film systems act in a manner similar to that which would be predicted if only the energy absorption properties of their screens were considered.