Abstract: An improved shielding structure for providing shielding from X-ray and gamma radiation, containing at least two, and possibly three layers of material, provided in specific order from the side in which X-ray or gamma radiation is received. The first layer in order has K-edge and L.sub.I -edge levels of a first range. The second layer in order has K-edge levels between the K-edge and L.sub.I -edge levels, and lower than a secondary radiation level which is emitted by the first layer. A third layer in order has K-edge levels between the K-edge and L.sub.I -edge levels of the second layer. Materials such as uranium, lead, and gold, among others, may be used in the first layer. Materials such as tin and indium, among others, may be used in the second layer. Materials such as zinc, copper, nickel, and chromium, among others, may be used in the third layer.

Abstract: Method and modifying body for influencing the effect of X-ray or gamma radiation on a target (7) sensitive to radiation, in particular for selective modification of a radiograph of an object (10). According to the invention a modifying body comprising at least two layer groups (31, . . . 3n) is arranged in front of the target, wherein each layer group (e.g., 32) emits a secondary radiation under the influence of the X-ray or gamma radiation or the secondary radiation of the previous layer group (e.g., 31), respectively, the energy of which is lying above the absorption energy level defined by the electron shell K of an element being present in the following layer group (e.g., 33) or in the target arranged behind the last layer group (3n), respectively.