Abstract: Disclosed herein is an apparatus suitable for detecting x-ray, comprising: an X-ray absorption layer configured to generate an electrical signal from an X-ray photon incident on the X-ray absorption layer; an electronics layer comprising an electronics system configured to process or interpret the electrical signal; wherein at least one of the X-ray absorption layer and the electronics layer is embedded in a board of an electrically insulating material.

Abstract: Disclosed herein is an image sensor comprising: a plurality of packages arranged in a plurality of layers; wherein each of the packages comprises an X-ray detector mounted on a printed circuit board (PCB); wherein the packages are mounted on one or more system PCBs; wherein within an area encompassing a plurality of the X-ray detectors in the plurality of packages, a dead zone of the packages in each of the plurality of layers is shadowed by the packages in the other layers.

Abstract: An apparatus suitable for detecting X-ray is disclosed. In one example, the apparatus comprises an X-ray absorption layer comprising a first pixel and a second pixel, and a controller. The controller is configured for determining that carriers generated by a single X-ray photon are collected by the first pixel and the second pixel. The controller is also configured for determining energy of the single X-ray photon based on a first voltage detected from the first pixel and a second voltage detected from the second pixel. The first voltage and the second voltage are caused by the single X-ray photon.

Abstract: Disclosed herein is a method for making an apparatus suitable for detecting X-ray, the method comprising: bonding a plurality of chips to a substrate; wherein the substrate comprises an X-ray absorption layer comprising a first plurality of electrical contacts; wherein each of the plurality of chips comprises an electronic layer comprising a second plurality of electrical contacts and an electronic system configured to process or interpret signals generated by X-ray photons incident on the X-ray absorption layer; aligning the first plurality of electrical contacts to the second plurality of electrical contacts; mounting the chips to the substrate such that the first plurality of electrical contacts are electrically connected to the second plurality of electrical contacts; wherein the second plurality of electrical contacts are configured to feed the signals to the electronic system.

Abstract: Disclosed herein is a detector, comprising: a plurality of pixels, each pixel configured to count numbers of X-ray photons incident thereon whose energy falls in a plurality of bins, within a period of time; and wherein the detector is configured to add the numbers of X-ray photons for the bins of the same energy range counted by all the pixels. Each of the pixels may comprise an analog-to-digital converter (ADC) configured to digitize an analog signal representing the energy of an incident X-ray photon into a digital signal. The pixels may be able to operate in parallel. Each of the pixels may be able to measure its dark current, such as before or concurrently with each X-ray photon incident thereon.

Abstract: Disclosed herein is an image sensor and a method of making the image sensor. The image sensor may comprise one or more packages of semiconductor radiation detectors. Each of the one or more packages may comprise a radiation detector that comprises a radiation absorption layer on a first strip of semiconductor wafer and an electronics layer on a second strip of semiconductor wafer. The radiation absorption layer may be continuous along the first strip of semiconductor wafer with no coverage gap. The first strip and the second strip may be longitudinally aligned and bonded together. The radiation detector may be mounted on a printed circuit board (PCB) and electrically connected to the PCB close to an edge of the radiation detector.

Abstract: Disclosed herein is an apparatus comprising: an X-ray absorption layer; a first electrical contact and a second electrical contact on opposing surfaces of the X-ray absorption layer; wherein the first electrical contact and the second electrical contact respectively comprise structures extending into the X-ray absorption layer.

Abstract: Disclosed herein is an X-ray detector comprises: an X-ray absorption layer configured to absorb X-ray photons; an electronics layer comprising an electronics system configured to process or interpret signals generated by the X-ray photons incident on the X-ray absorption layer; and a temperature driver in the X-ray absorption layer or the electronics layer.

Abstract: Disclosed herein is an apparatus comprising: a radiation absorption layer comprising an electrode; a counter configured to register a number of radiation particles absorbed by the radiation absorption layer; a controller configured to start a time delay from a time at which an absolute value of an electrical signal on the electrode equals or exceeds an absolute value of a first threshold; a comparator configured to compare the electrical signal to a second threshold; wherein the controller is configured to activate the comparator during the time delay; wherein the controller is configured to cause the number registered by the counter to change, if the comparator determines that an absolute value of the electrical signal equals or exceeds an absolute value of the second threshold.

Abstract: Disclosed herein is an apparatus suitable for detecting X-ray, comprising: an X-ray absorption layer comprising an electrode; an electronics layer, the electronics layer comprising: a substrate having a first surface and a second surface, an electronics system in or on the substrate, an electric contact on the first surface, a via, and a transmission line on the second surface; wherein the via extends from the first surface to the second surface; wherein the electrode is electrically connected to the electric contact; wherein the electronics system is electrically connected to the electric contact and the transmission line through the via.

Abstract: Disclosed herein is a method comprising: exposing an imaging system to a scene of a radiation, the imaging system comprising a radiation detector, wherein a probability of having two or more particles of the radiation from the scene incident on an area of the radiation detector during a frame within a time period of detection is below a threshold; detecting particles of the radiation from the scene with the imaging system; if the imaging system detects two or more particles in the area within the frame, combining signals caused by the two or more particles as a combined signal and recording the combined signal, or disregarding the signals caused by the two or more particles; if the imaging system detects only one particle, recording a signal caused by the only one particle; after an end of the time period of detection, forming an image with signals recorded.

Abstract: Disclosed herein is a radiation detector, comprising: a radiation absorption layer comprising an electrode; a capacitor module electrically connected to the electrode and comprising a capacitor, wherein the capacitor module is configured to collect charge carriers from the electrode onto the capacitor; a current sourcing module in parallel to the capacitor, the current sourcing module configured to compensate for an electrical current of a dark noise in the radiation detector and comprising a current source and a modulator; wherein the current source is configured to output a first electrical current and a second electrical current; wherein the modulator is configured to control a ratio of a duration at which the current source outputs the first electrical current to a duration at which the current source outputs the second electrical current.

Abstract: Disclosed herein is a computed tomography system, comprising: a table with a hole therein, wherein the table is configured to support a person lying face down thereon, with at least one of the person's breasts projecting through the hole; an X-ray source; an X-ray detector comprising a plurality of pixels; wherein the X-ray source is configured to rotate around the at least one of the person's breasts.

Abstract: Disclosed herein is an apparatus comprising: an array of avalanche photodiodes (APDs), each of the APDs comprising an absorption region and an amplification region; wherein the absorption region is configured to generate charge carriers from a photon absorbed by the absorption region; wherein the amplification region comprises a junction with an electric field in the junction; wherein the electric field is at a value sufficient to cause an avalanche of charge carriers entering the amplification region, but not sufficient to make the avalanche self-sustaining; wherein the junctions of the APDs are discrete.

Abstract: Disclosed herein is a method to measure an intensity distribution of X-ray using an X-ray detector, the method comprising: determining values of dark current at at least three locations on the X-ray detector, wherein the three locations are not on a straight line; determining a spatial variation of absorptance of the X-ray using the values of the dark current; measuring an apparent intensity distribution of the X-ray; determining the intensity distribution by removing a contribution of the spatial variation the absorptance from the apparent intensity distribution.

Abstract: Disclosed herein is a method of making an apparatus suitable for detecting x-ray, the method comprising: obtaining a substrate having a first surface and a second surface, wherein the substrate comprises an electronic system in or on the substrate, wherein the substrate comprises a plurality of electric contacts are on the first surface; obtaining a first chip comprising a first X-ray absorption layer, wherein the first X-ray absorption layer comprises an electrode; bonding the first chip to the substrate such that the electrode of the first X-ray absorption layer is electrically connected to at least one of the electric contacts.

Abstract: An apparatus suitable for detecting X-ray is disclosed. In one example, the apparatus comprises an X-ray absorption layer comprising a first pixel and a second pixel, and a controller. The controller is configured for determining that carriers generated by a single X-ray photon are collected by the first pixel and the second pixel. The controller is also configured for determining energy of the single X-ray photon based on a first voltage detected from the first pixel and a second voltage detected from the second pixel. The first voltage and the second voltage are caused by the single X-ray photon.

Abstract: Disclosed herein is a method to measure an intensity distribution of X-ray using an X-ray detector, the method comprising: determining values of dark current at at least three locations on the X-ray detector, wherein the three locations are not on a straight line; determining a spatial variation of absorptance of the X-ray using the values of the dark current; measuring an apparent intensity distribution of the X-ray; determining the intensity distribution by removing a contribution of the spatial variation the absorptance from the apparent intensity distribution.

Abstract: Disclosed herein is a method of making an apparatus suitable for detecting x-ray, the method comprising: obtaining a substrate having a first surface and a second surface, wherein the substrate comprises an electronics system in or on the substrate, wherein the substrate comprises a plurality of electric contacts are on the first surface; obtaining a first chip comprising a first X-ray absorption layer, wherein the first X-ray absorption layer comprises an electrode; bonding the first chip to the substrate such that the electrode of the first X-ray absorption layer is electrically connected to at least one of the electrical contacts.

Abstract: Disclosed herein is an apparatus for detecting X-ray. The apparatus has an X-ray absorption layer with an electrode, one or more voltage comparators configured to compare a voltage of the electrode to one or more thresholds, a counter configured to register the number of X-ray photons absorbed by the X-ray absorption layer, and a controller.