Nomographs to Determine the Effective Thickness of X-Ray Shields

All kinds of matter (gases, liquids and solids) have the ability of reducing the intensity of X-Rays. This property depends on the wave lenght of an X-Ray, and of the kind of matter used for this purpose. As a rule, some metals are known to be the best shields (screens) against X-Rays. An X-Ray screen of a specified thickness which absorbs one-half of the initial radiation intensity of a given wave length, is defined as a "half-layer-screen". A Nomograph is presented, which allows to find in the quickest possible time the "hslf-layer-thickness" of X-Ray screens, prepared from a number of the most commonly used materials. The second Nomograph presented enables to find the desired thickness of an X-Ray screen which reduces the initial radiation intensity to any level wanted.