A METHOD AND A DEVICE FOR PLANAR BEAM RADIOGRAPHY AND A RADIATION DETECTOR

摘要

A method and apparatus for radiography, and especially for planar beam radiography, and also a detector for detecting incident radiation. In the method and apparatus, wherein X-rays (9) are emitted from an X-ray source (60), the X-rays are formed into a planar beam and are transmitted through an object to be imaged (62), and the X-rays transmitted through said object (62) are detected in a detector (64). The detector (64), which detects incident radiation is a gaseous parallel plate avalanche chamber, including electrode arrangements between which a voltage is applied for creating an electrical field, which causes electron-ion avalanches of primary and secondary ionization electrons released by incident radiation. The detector (64) is oriented, in relation to the incident radiation (9), so that the radiation enters sideways between a first and a second parallel plate, between which the electrical field is created. Electrical signals induced by said electron-ion avalanches are detected in at least one detector electrode arrangement, including a plurality of detector electrode elements arranged adjacent to each other, each along a direction being essentially parallel to the incident radiation. Pulses from each detector electrode element are processed in processing electronics, for obtaining values for each pixel corresponding to the respective detector electrode element.