Abstract: A ganged-detector pixel cell is used in a device having an array of such pixel cells to construct an x-ray and gamma-ray radiation energy imaging device. The ganged-detector pixel cell comprises a detector pixel array of two or more detectors pixels disposed on a semiconductor detector substrate. The detector pixels of the pixel array are in electrical communication with a single pixel signal counting circuit disposed on an adjacent ASIC readout substrate. The ganged-detector pixel cell has a Ratio of Correspondence (RC) between of the number of pixel detectors to the single pixel signal counting circuits in the cell of RC?1. In practice, the Ratio of Correspondence between of the number of pixel detectors to the single pixel signal counting circuits in a pixel cell is RC?2.

Abstract: An imaging system for high energy radiation direct conversion scan imaging includes a high energy radiation source and a semiconductor high energy radiation direct conversion imaging device arranged around an object position. The imaging device includes a plurality of imaging cells, each imaging cell comprising a detector cell and a readout cell for producing imaging cell output values representative of high energy radiation incident on the detector cell. The source member and/or the imaging device were arranged to move substantially continuously relative to each other for scanning an object at the object position. The readout cells are operated to read out the imaging cell output values at time intervals which substantially correspond to an object image point traversing half the distance of a detector region or cell in the scanning direction. Such a configuration provides for pixel level resolution during the scanning operation.

Abstract: An imaging system for high energy radiation direct conversion scan imaging includes a high energy radiation source and a semiconductor high energy radiation direct conversion imaging device arranged around an object position. The imaging device includes a plurality of imaging cells, each imaging cell comprising a detector cell and a readout cell for producing imaging cell output values representative of high energy radiation incident on the detector cell. The source member and/or the imaging device were arranged to move substantially continuously relative to each other for scanning an object at the object position. The readout cells are operated to read out the imaging cell output values at time intervals which substantially correspond to an object image point traversing half the distance of a detector region or cell in the scanning direction. Such a configuration provides for pixel level resolution during the scanning operation.

Abstract: A ganged-detector pixel cell is used in a device having an array of such pixel cells to construct an x-ray and gamma-ray radiation energy imaging device. The ganged-detector pixel cell comprises a detector pixel array of two or more detectors pixels disposed on a semiconductor detector substrate. The detector pixels of the pixel array are in electrical communication with a single pixel signal counting circuit disposed on an adjacent ASIC readout substrate. The ganged-detector pixel cell has a Ratio of Correspondence (RC) between of the number of pixel detectors to the single pixel signal counting circuits in the cell of RC≧1. In practice, the Ratio of Correspondence between of the number of pixel detectors to the single pixel signal counting circuits in a pixel cell is RC≧2.

Abstract: A method of autoradiography imaging includes steps of: (a) forming a subject having at least first and second markers, each marker providing radiation having a characteristic energy distribution; (b) detecting radiation from the marked subject using a semiconductor radiation detector having an array of cells, each cell recording a charge value dependent on the energy of incident radiation; (c) processing the output from the cells including discriminating charge values within at least two charge value ranges and allocating a display color value to each pixel cell position in the array dependent upon the recorded charge value; and (d) forming an image for display with individual cell positions having a color representative of the color values. The method enables multiple label or multiple marker imaging in autoradiography to be performed by energy discriminating imaging, thus enhancing experimental accuracy and reproducibility.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: A semiconductor imaging device includes a semiconductor radiation detector substrate, for example of cadmium zinc telluride, with at least two faces. A first face has at least one charge output contact formed from electrically conductive material or materials and a second face having a contact formed from electrically conductive material or materials. The second face contact is for applying a bias voltage to provide an electric field between the first and second faces. The second face contact, or a third face of the semiconductor imaging device, or an edge between the second and third faces has deposited thereon at least a partial covering of a further material different from the electrically conductive material or materials of the second face contact. The deposited material can be a semiconductor, insulating or passivation material, for example aluminium nitride. Such a radiation detector can provide linear detector behaviour for all possible combinations of exposure and X-ray tube voltage.

Abstract: An imaging support for supporting a plurality of imaging device tiles at respective tile mounting locations to define a tiled imaging surface is provided. Each of the imaging device tiles has a semiconductor detector with a plurality of pixel cells coupled to a semiconductor substrate with a corresponding plurality of pixel circuits. The semiconductor detector and the semiconductor substrate are carried on a mount having an imaging device tile contact. The imaging support is configured for mounting each of the imaging device tiles on the imaging support in a non-destructive, removable manner at respective tile mounting locations, each of which includes an imaging support contact at a contact position.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: A radiographic imaging system includes a plurality of radiation imaging devices arranged in a plurality of columns. The plurality of columns are tiled together to form a mosaic, with imaging devices in adjacent columns being offset from one another in a columnar direction. A radiation source is provided to irradiate an object to be imaged. An absorption grid is disposed between the radiation source and the mosaic, shielding a portion of the object to be imaged from radiation emitted by the radiation source.

Abstract: An imaging support for supporting imaging devices in respective positions to define an imaging surface is arranged to permit the imaging devices to be removably mounted on the support in a non-destructive, removable manner. In one embodiment the removable mounting is achieved by providing a source of reduced air pressure behind the imaging devices on the imaging support to suck the imaging devices onto the imaging support so that the imaging devices are accurately located on the support in a removable, non-destructive manner. The imaging devices are removable without damage to the device to be removed, the surrounding devices or the support. Defective devices can readily and quickly be replaced. Correctly functioning imaging devices can easily be removed and re-used on the same or a different imaging support.