X-RAY ABSORPTION, SPEED, AND LUMINESCENT EFFICIENCY OF RARE-EARTH AND OTHER INTENSIFYING SCREENS

Seven new and two conventional screens were investigated. Measurements were performed at different energies of the photon fraction interacting in the screens, and energy losses due to escape of K-fluorescent radiations were calculated. The speed of the screens was dependent on the energy; this was primarily due to the fact that X-ray absorption is dependent on energy. Rare earth and other new screens absorb a maximum of 1.5 times as much energy and emit twice as much light as comparable calcium tungstate screens. Reabsorbed K-fluorescent radiations might contribute to image unsharpness in the new screens.