Gamma-ray irradiation apparatus

987,884. Irradiation apparatus. MEDICOR RONTGEN MUREK. Feb. 14, 1962, No. 5712/62. Heading H5R. The radio-active source in an irradiation apparatus is movable between a non-operative position where it is shielded within a supporting wall, and an operative position in an irradiation head where it can be rotated so that the radiation beam always passes through a predetermined fixed point, the source being movable from one position to the other by gravityoperated means. In the arrangement shown, the radiation source 3 is located between two lead cylinders to form a unitary shell. This can be moved from a storage position within a container 5 to an operative position in a head 4 through a rigid connecting tube 6. Tube 6 has an inner steel tube 7, with a lead layer between them, and the shell actually moves within this inner tube 7, being fixed to the end of a rod 13. The rod pushes the source from within container 5 into the head 4, and retracts it back again. Fig. 3 (not shown) illustrates an arrangement of weights and pulleys for effecting these movements. The head 4 is formed as a lead ball, with a conical exit orifice 21 for the rays, and having exchangeable lead diaphragms 22. The storage container 5 is enclosed in a section 9 of the concrete wall 8 of the chamber in which the irradiation takes place. The wall section 9, and hence the whole device, is rotatable about a horizontal shaft 11. The device is inclined, as shown, so that as it rotates the beam of radiation from the head 4 always passes through a predetermined fixed point.