GB699792A - Improvements in or relating to means for photographically recording the tracks of atomic or sub-atomic particles or ether waves emitted by radioactive substances or by irradiated substances - Google Patents

Abstract

699,792. 'Recording radiation and like tracks. WEARHAM, J. May 23, 1950 [May 23, 1949], No. 13693/49. Classes 98 (i) and 98 (ii). [Also in Group XL (a)] A block, e.g. a cube, slab, cylinder or sphere, of material the optical properties of which are altered by the passage therethrough of atomic or sub-atomic particles or radiation, is provided with one or more holes for insertion of a primary source of rays or particles, or alternatively a substance which emits secondary rays or particles when irradiated by primary radiation. The block may be made of silver halide ,photographic emulsion in which the ray or particle tracks are rendered visible on development, and may be contained in a shielding container. To enable the block to'be developed, it may be cut into sheets or coils, developed, and re-assembled. Alternatively, 'the block may be rendered porous as by 'casting it round fine wires or the like which are then withdrawn. The block may be made up of separable units put together before exposure, separated after exposure, and reassembled after development. A number of sheets may be pinned together by the corners at K, Fig. 2, to form a block with a hole at a or a<SP>1</SP> for the radiating material. The sheets are fanned apart for development. Alternatively, the sheets are mounted on guide rods passing through holes in the corners, or joined at the edges, or connected at their edges to elastic sheets. Sheet material may be wrapped into a cylinder of square cross-section (Fig. 9) or circular cross-section (Fig. 11) or formed into nesting shapes making up such cylinders. Spacing material may be provided. The block may have a shielding container in which it may be processed. In Fig. 15 a container d contains a homogeneous block b. An aperture with a cover c is provided in the container so that the radiation source can be introduced into the hole a in the block. After exposure, a multi-blade cutter e is screwed down by a handle m to cut the block into sheets. Processing liquids are admitted to and drained from the container by means of taps h. When the block is made in several parts, the parts may be marked or numbered for re-assembly. Re-assembled blocks may be united by heat and pressure or cementing, cemented between plates or within a cylinder of glass which may have a non- reflecting surface layer. The material of the block may contain fluorescent substances, sensitizing dyes, or halation inhibitors.