Patent ID: 6118125
Filing Date: 2000-09-12
Classification: G01T,H05G

Abstract:
A method for obtaining images in planar beam radiography, whereinemitting X-rays from an X-ray source,forming the X-rays into a planar beam and transmitting said X-rays through an object to be imaged,detecting the X-rays transmitted through said object in a gaseous avalanche detector including electrode arrangements between which a voltage is applied for creating an electrical field, wherein the X-rays in a gaseous parallel plate avalanche chamber are oriented so that the radiation to be detected enters substantially sideways between a first and a second parallel plate,applying the voltage between a first and a second electrode arrangement, included in the first and the second parallel plate, respectively, for creating the electrical field which causes electron-ion avalanches of primary and secondary ionization electrons released by incident X-ray photons, wherein the depth of the gaseous parallel plate avalanche chamber, in the direction of the incident radiation, is such as to permit interaction of a majority of the incident X-ray photons with gas atoms, for the production of primary ionization electron-ion pairs, within the detector,detecting electrical signals in at least one detector electrode arrangement, said electrical signals being induced by said electron-ion avalanches, in at least one of a plurality of detector electrode elements arranged adjacent to each other, each along a direction substantially parallel to the incident radiation.