Abstract: A hybrid imaging detector is for detecting ionizing radiation such as X-rays or electron radiation, or other ionizing radiation. The detector has a sensor (10) on a read-out chip (20). The sensor (10) includes a plurality of sensor material layers (12,14) of different materials stacked on top of one another, having differing radiation absorbing properties. The materials may be Si and SiGe, Si and Ge, or Si and amorphous Se, for example. The read-out chip is a photon-counting read-out chip that records a single count when it detects a pulse above a threshold.

Abstract: A hybrid imaging detector is for detecting ionizing radiation such as X-rays or electron radiation, or other ionizing radiation. The detector has a sensor (10) on a read-out chip (20). The sensor (10) includes a plurality of sensor material layers (12,14) of different materials stacked on top of one another, having differing radiation absorbing properties. The materials may be Si and SiGe, Si and Ge, or Si and amorphous Se, for example.

Abstract: A sensor for detecting ionizing radiation such as X-rays or electrons in an imaging detector, with a germanium substrate 12 and top and bottom silicon layers 14,16. The silicon layers may be passivated. The bulk of absorption takes place in the germanium. Anode and cathode electrodes 44, 46 may be provided alternately to laterally bias the substrate. Alternatively, the silicon layers may be doped to vertically bias the substrate.

Abstract: In order to obtain suitable absorption of the radiation to be detected in the detector gas of a radiation detector, in particular an X-ray detector, the detector is constructed in such a way that the radiation enters the detector parallel to the counting wire, thus offering an absorption path having any desired length. According to the invention, a number of avalanche chambers 50 is arranged adjacent the absorption chamber 46, said avalanche chambers having a comparatively small cross-section. The avalanche chambers are provided with grids 54 in such a way that charge multiplication by the grid voltage can occur only in the avalanche chamber. Due to the comparatively small cross-section of the avalanche chambers, broadening of the current impulses to be detected is prevented. Moreover, the comparatively long absorption chamber offers good radiation absorption and the presence of several avalanche chambers enables a favourable detection rate.