Comparative study on film-density intensifying screens for high energy bremsstrahlungs. 1

In order to confirm experimentally contentions of Germany and so forth and to obtain some useful data on high energy X-ray with more than some MeV to supply for common reference, the Working Group for the Research of Film-density Intensifying Screens for High Energy X-rays was organized in the Research and Technical Committee on Radiographic Testing, JSNDI to conduct some comparative investigations on Pb-, SUS- and Cu-screens. As a result, it was found that on intensification rate Pb-screen was excellent. However, performance of the intensifying screens seemed to be necessary to judge comprehensively by considering of their intensification rates, identification degrees, image qualities, and so forth to use them effectively. As here was described their intensification rates without a subject, it was presumed that the intensifying effect was a little different from these results because of scattering and absorption of incident ray when a subject was present. (G.K.)