Ionizing radiation detector with reduced street width and improved count rate stability
An ionizing radiation detector, such as a photon counting computed tomography detector, includes a semiconductor material plate, a plurality of anodes located on a first side of the semiconductor material plate, where the gaps (i.e., streets) between adjacent anodes are less than 15 μm in width, and at least one cathode located on a second side of the semiconductor material plate. Ionizing radiation detectors according to various embodiments may have improved count rate stability (CRS) characteristics and a reduced number of Non-Conforming Pixels (NCPs) relative to conventional detectors.
1. An ionizing radiation detector, comprising:
a semiconductor material plate;
a plurality of anodes located on a first side of the semiconductor material plate, wherein gaps between adjacent anodes of the plurality of anodes are less than 15 μm in width; and
at least one cathode located on a second side of the semiconductor material plate.
2. The ionizing radiation detector of claim 1 , wherein the ionizing radiation detector comprises a photon counting computed tomography detector.
3. A photon counting computed tomography imaging system, comprising:
the ionizing radiation detector of claim 2 ;
an X-ray source configured to emit an X-ray beam towards the ionizing radiation detector and an object located between the X-ray source and the ionizing radiation detector; and
a control unit configured to control the operation of the X-ray source and the ionizing radiation detector to obtain images of the object.
4. The photon counting computed tomography system of claim 3 , further comprising:
a high voltage bias power supply coupled to the ionizing radiation detector and configured to generate an electric field in the semiconductor material plate;
a read-out circuit coupled to the plurality of anodes and configured to receive electrical signals from each of the anodes; and
a processor coupled to the read-out circuit and configured to generate images of the object based on the electrical signals received from the read-out circuit.
5. The ionizing radiation detector of claim 1 , wherein the semiconductor material plate comprises a cadmium zinc telluride semiconductor material plate.
6. The ionizing radiation detector of claim 1 , wherein the width of the gaps between adjacent anodes of the plurality of anodes are between 0.1 μm and 14 μm.
7. The ionizing radiation detector of claim 4 , wherein the width of the gaps between adjacent anodes of the plurality of anodes are between 5 μm and 10 μm.
8. The ionizing radiation detector of claim 1 , wherein the ionizing radiation detector comprises a plurality of detector pixels and each detector pixel contains one anode of the plurality of anodes.
9. The ionizing radiation detector of claim 6 , wherein the at least one cathode comprises a single cathode located on the second side of the semiconductor material plate, and the cathode extends over all of the detector pixels of the ionizing radiation detector.
10. The ionizing radiation detector of claim 6 , wherein the ionizing radiation detector has at least 25% less non-conforming pixels from a 1 minute count rate stability measurement than an equivalent ionizing radiation detector in which the gaps between adjacent anodes are 35 μm.
11. The ionizing radiation detector of claim 1 , further comprising a passivation layer located within the gaps between adjacent anodes of the plurality of anodes on the first side of the semiconductor material plate.
12. The ionizing radiation detector of claim 8 , wherein the passivation layer extends beneath the plurality of anodes on the first side of the semiconductor material plate.
13. The ionizing radiation detector of claim 1 , further comprising a read-out integrated circuit having charge sensitive amplifier inputs connected to respective anodes of the plurality of anodes.