Abstract: A photon-guiding device for a radiotherapy apparatus, consists of a central frustum, made up of a plurality of metal channels, and an outer casing that encloses the central frustum and consists of microchannels. The channels and microchannels have a frusto-conical shape and a common apex.

Abstract: A photon-guiding device for a radiotherapy apparatus, consists of a central frustum, made up of a plurality of metal channels, and an outer casing that encloses the central frustum and consists of microchannels. The channels and microchannels have a frusto-conical shape and a common apex.

Abstract: Apparatus for storing fuel elements in cells placed at the bottom of a pool and separated by a water gap, the walls of the cells being externally covered with a neutrophage material layer. A layer constituted by a single thin cadmium sheet continuously covers the outer surface of the walls in accordance with the periphery of the cell. This single thin sheet is held in place and protected by a thin metal plate, preferably of stainless steel.

Abstract: An inner tube (1) and an outer tube (6) are provided of suitable shape and size for the inner tube to be received coaxially inside the outer tube, thereby causing the outside face of the inner tube to face the inside face of the outer tube. A neutron-absorbing screen (2) is fixed to one of said faces. The inner tube is inserted into the outer tube, and the inner tube is radially expanded into the outer tube while leaving the outer tube externally free to expand, and thereby plastically deforming both tubes and obtaining a solid single block assembly of desired shape and size for the container. The container may be used for storing radioactive material.