| 摘要 |
A system comprising an X-ray source (1), an elongate detector tube (3) including at least one cathode (5) extending in the longitudinal direction of the tube and at least one anode (6) located opposite to the cathode, a slit diaphragm (2), and a filter (4) mounted in the path between the X-ray source (1) and the detector tube (3). The filter (4) blocks relatively low energy X-radiation in a portion of the beam emitted by the source (1). The cathode (5) is provided with an X-ray detection layer consisting of two strips (8',8'') extending in the longitudinal direction of the tube (3). One strip (8'') receives the radiation passed by the filter (4) and the other strip (8') receives the unfiltered radiation. The one strip (8'') is of considerably greater thickness than the other strip (8'). |
