Abstract: A method and apparatus for locating a collar of a casing of a wellbore is disclosed. A sensor for measuring a magnetic field is conveyed through the casing on a tool string. A physical model is formed of a process of obtaining a magnetic measurement of the casing with the sensor. A simulation of the physical model is run through a processor to select a design parameter of the tool that allows for using the sensor at a determined value of an operational parameter for obtaining the measurement at a selected signal-to-noise ratio. The tool is conveyed into the wellbore and the sensor set to the determined value of the operational parameter. The magnetic measurement of the casing is obtained using the sensor, and the collar is located using the obtained magnetic measurement.

Abstract: A method and apparatus for locating a collar of a casing of a wellbore is disclosed. A sensor for measuring a magnetic field is conveyed through the casing on a tool string. A physical model is formed of a process of obtaining a magnetic measurement of the casing with the sensor. A simulation of the physical model is run through a processor to select a design parameter of the tool that allows for using the sensor at a determined value of an operational parameter for obtaining the measurement at a selected signal-to-noise ratio. The tool is conveyed into the wellbore and the sensor set to the determined value of the operational parameter. The magnetic measurement of the casing is obtained using the sensor, and the collar is located using the obtained magnetic measurement.

Abstract: A CdZnTe photon counting detector includes a core material of Cd1-xZnxTe, where (0?x<1), an anode terminal on one side of the core material and a cathode terminal on a side of the core material opposite the anode terminal. At least one of the following is selected in the design of the detector as a function of the maximum sustainable photon flux the core material is able to absorb in operation while avoiding polarization of the core material: electron lifetime-mobility product of the core material; de-trapping time of the core material; a value of a DC bias voltage applied between the anode and the cathode; a temperature of the core material in operation; a mean photon flux density to be absorbed by the core material in operation; and a thickness of the core material between the anode and the cathode.

Abstract: In operation of a photon counting detecting system (10), a number of pulse counts output by least one pixel (20) of a photon counting detector in response to experiencing a photon flux density during a sample interval is acquired and a photon flux density (46) or value related thereto corresponding to the pulse counts output by the pixel (20) is determined. A correction (48) for the thus determined photon flux density (46) or value related thereto is determined. A corrected number of pulse counts (52) is determined for the pixel (20) as a function of the thus determined corrected photon flux density value or value related thereto. An image can be displayed that is a function of the corrected number of pulse counts for pixels of the system.

Abstract: A CdZnTe photon counting detector includes a core material of Cd1-xZnxTe, where (0?x<1), an anode terminal on one side of the core material and a cathode terminal on a side of the core material opposite the anode terminal. At least one of the following is selected in the design of the detector as a function of the maximum sustainable photon flux the core material is able to absorb in operation while avoiding polarization of the core material: electron lifetime-mobility product of the core material; de-trapping time of the core material; a value of a DC bias voltage applied between the anode and the cathode; a temperature of the core material in operation; a mean photon flux density to be absorbed by the core material in operation; and a thickness of the core material between the anode and the cathode.

Abstract: In operation of a photon counting detecting system (10), a number of pulse counts output by least one pixel (20) of a photon counting detector in response to experiencing a photon flux density during a sample interval is acquired and a photon flux density (46) or value related thereto corresponding to the pulse counts output by the pixel (20) is determined. A correction (48) for the thus determined photon flux density (46) or value related thereto is determined. A corrected number of pulse counts (52) is determined for the pixel (20) as a function of the thus determined corrected photon flux density value or value related thereto. An image can be displayed that is a function of the corrected number of pulse counts for pixels of the system.