Radiation collimator with identical superimposed lead plates - contoured to locate together and provide hexagonal passages

摘要

The collimator consists of a number of superimposed metal, partic. lead, plates (1-4) of identical shape, each having parallel wall portions (5,6) connecting via inclined (alpha e.g. 120 deg. as shown) wall portions (-,8). The parallel wall portions of successive plates are in mutual contact, the configurations (5-8) being such that the plates define hexagonal passages (9) between them. The wall portions (5,6) are provided with complementary indentations (5b,c; 6b,c) which fit together and may be at an angle to one another (e.g. 120 deg. as shown) or may be curved over their full widths or part thereof. The indentations may extend in the longitudinal direction of the respective passages (9). The plates fit together thus providing accurate location relative to one another which is desirable to provide homogeneity and linearity of the radiation. The indentations prevent radiation leaks between the mutually engaging wall portions and strengthen the plates which reduces risk of deformation and consequent deterioration of collimator performance. The plate contours can be accurately produced by pressing which avoids undesirable fluctuations in wall thickness and consequent deformation when superimposed as experienced with rolled plates.