| 摘要 |
An x-ray collimator comprising a substrate containing a plurality of holes, each hole being frustoconical at one end 30 and tubular at the other end 50. The collimator is designed for use in an x-ray imaging system, being aligned with a two-dimensional array of x-ray sources and a two-dimensional x-ray sensor 130. In use, electrons from a plurality of adjacent electron sources 90 generate x-rays at a target material 70. Higher energy x-ray photons then pass through filter material 100, before passing through the collimator holes and emerging as an approximately parallel beam of x-ray photons which pass through the subject 110 being imaged. The frustoconical portions of each collimator hole are preferably approximately defined by a parabolic shape known as a Winston Cone, while the tubular portions are cylindrical. The holes are also preferably lined on their inner surface with a plurality of thin film materials such as tungsten, iridium, aluminium oxide, silicon and/or carbon. |
