Charge sharing correction methods for sub-pixellated radiation detector arrays

A method of calibrating a pixel radiation detector comprising an array of pixels each comprising an array of sub-pixel detectors to account for inter-sub-pixel charge sharing effects, comprising:

• exposing the imaging radiation detector to radiation from a source of gamma photons of a known energy or energy spectrum;
• measuring gamma photon energies detected by the pixel radiation detector using electronics capable of registering simultaneous, coincident detection events occurring in two or more sub-pixel detectors within a pixel;
• determining energies of gamma photons detected in sub-pixel detectors within a pixel for detection events occurring simultaneously in two or more sub-pixel detectors within a pixel which comprise sub-pixel simultaneous detection events;
• and
• determining a sub-pixel charge sharing correction factor based upon the radiation source known gamma photon energy and determined energies of gamma photons detected in sub-pixel detectors within a pixel in sub-pixel simultaneous detection events.

An imaging radiation detector, comprising:

• an array of pixels each comprising an array of sub-pixel detectors;
• and
• detector processing circuitry coupled to each sub-pixel detector, the detector processing circuitry capable of registering simultaneous, coincident detection events occurring in two or more sub-pixel detectors within any pixel and configured to:
• sum energy measurements of detection events occurring simultaneously in two or more sub-pixel detectors within a pixel which comprise sub-pixel simultaneous detection events to obtain a first energy measurement of multi-subpixel detection events;
• adjust the first energy measurements of sub-pixel simultaneous detection events by a sub-pixel charge sharing correction factor;
• and
• determine a corrected gamma photon energy spectrum by adding the adjusted energy measurements of sub-pixel simultaneous detection events to gamma photon energy measurements of detection events occurring in single sub-pixel detectors.

An imaging radiation detector, comprising:

• an array of pixels each comprising an array of sub-pixel detectors;
• means for summing energy measurements of detection events occurring simultaneously in two or more sub-pixel detectors within a pixel which comprise sub-pixel simultaneous detection events to obtain a first energy measurement of multi-subpixel detection events;
• means for adjusting the first energy measurements of sub-pixel simultaneous detection events by a sub-pixel charge sharing correction factor;
• and
• means for determining a corrected gamma photon energy spectrum by adding the adjusted energy measurements of sub-pixel simultaneous detection events to gamma photon energy measurements of detection events occurring in single sub-pixel detectors.