Abstract: A device for determining radon concentration is provided. The device includes a diffusion chamber, that includes a number of openings that allow radon gas to enter and exit, and a radon sensing arrangement. The radon sensing arrangement includes at least one processing device and one or more detectors, arranged inside the diffusion chamber in such a way that no part of the diffusion chamber is located at a distance, perpendicular to the detector, of more than 20 mm from the closest part of a detector. The at least one processing device is arranged to determine the radon concentration by analyzing and processing the energy spectrum of alpha particles detected by the one or more detectors.

Abstract: A method and device for producing an X-ray pixel detector, for X-ray photons, the detector presenting high efficiency combined with high resolution for obtaining a high image quality detector while at the same time minimizing the X-ray dose used. The application is particularly important whenever the X-ray photon absorption distance is much longer than the required pixel size. The arrangement presents a structure based on light-guiding of secondarily produced photons within a scintillating pixel detector in conjuction with, a CCD or a CMOS pixel detector. The structure presents a matrix (8) having deep pores (10) fabricated by high-aspect ratio silicon etching techniques producing very thin walls and with a pore spacing less or equal to the size of a pixel (2) of the image detector used. The pore matrix is subsequently filled by melting a scintillating material into the pores such that, in each pore, a single scintillating block is formed.

Abstract: An X-ray imaging system comprising an X-ray image sensor and an image capture controller is provided. The X-ray image sensor includes a sensor array comprising a plurality of CMOS active column sensors. The image capture controller communicates with the X-ray image sensor to read out pixel values from selected ones of the CMOS active column sensor elements. The image capture controller may randomly select reference pixels from the plurality of CMOS active column sensor elements, and compare a signal of the reference pixels to a predetermined level to determine a start of X-ray exposure. The image capture controller also may randomly select second reference pixels from the plurality of CMOS active column sensor elements, and monitor the second reference pixels to determine an end of X-ray exposure. The X-ray imaging system also may include a wireless interface for coupling the X-ray image sensor to the image capture controller. The X-ray imaging system may be used as a dental X-ray imaging system.

Abstract: A number of randomly distributed pixels in a solid state X-ray imager are designated reference pixels. The distribution of reference pixels may be either totally random or in a limited number of rows or columns. The reference pixels may include predetermined pixels or pixel like elements located in rows or columns distributed in at least two different locations on the sensor. The reference pixels are well distributed to avoid missed exposures due to shading of the reference pixels by dense objects. To determine commencement of exposure the reference pixels are continuously monitored for signal. If the signal level in a predetermined minimum number of pixels exceeds the predetermined threshold, an image capture sequence starts. Otherwise, the entire image sensor is cleared and the signal monitoring continues. The threshold level is set to prevent accidental triggering by dark current at all operating temperatures of interest.