Side-electrodes for a Faraday cage on a photon-counting detector array

1. A computed tomography (CT) detector apparatus, comprising:

a plurality of detectors, each detector being arranged inside a Faraday cage having a plurality of voltage-biased side electrodes arranged on at least one side surface of the Faraday cage.

2. The apparatus of claim 1 , wherein the detectors include photon counting detectors (PCDs).

3. The apparatus of claim 1 , wherein the detectors are arranged in a ring.

4. The apparatus of claim 2 , wherein each PCD comprises:

a rectangular semiconductor crystal having a first face and a second face, wherein the first face and the second face are parallel;

a cathode side including a cathode electrode covering the first face; and

an anode side including a plurality of anode pixels on the second face.

5. The apparatus of claim 4 , wherein a voltage applied to the voltage-biased side-electrodes decreases from the anode face of the PCD to the cathode face of the PCD.

6. The apparatus of claim 4 , wherein the semiconductor crystal is one of CdZnTe and CdTe.

7. The apparatus of claim 1 , wherein the Faraday cage is composed of a low-Z material.

8. The apparatus of claim 2 , wherein each PCD further comprises:

a collimator; and

a dielectric insulating material disposed between the PCD and the collimator.

9. The apparatus of claim 1 , wherein the side electrodes are arranged in two groups on opposite sides of the Faraday cage and the side electrodes in each group are horizontal-strip electrodes.

10. The apparatus of claim 9 , wherein the side-electrodes in each group are single resistor-embedded zig-zag electrodes.

11. The apparatus of claim 2 , wherein a width of each of side-electrodes is reduced to enable a uniform operating field inside the PCD.

12. The apparatus of claim 2 , wherein a single vertical chain of resistors are used to connect the side-electrodes together, a first end of the single vertical chain of resistors being connected to a cathode of the PCD, and a second end of the single vertical chain of resistors being connected to an anode of the PCD.

13. The apparatus of claim 2 , wherein multiple vertical chains of resistors are used to connect the side-electrodes together, a first end of each of the multiple vertical chains of resistors being connected to a cathode of the PCD, and a second end of each of the multiple vertical chains of resistors being connected to an anode of the PCD.

14. The apparatus of claim 2 , wherein the side electrodes are arranged in two groups on opposite sides of the Faraday cage and the side electrodes in each group are vertical-strip electrodes with embedded resistors, a first end of each of the side-electrodes being connected to a cathode of the PCD, and a second end of each of the side-electrodes being connected to an anode of the PCD.

15. The apparatus of claim 2 , further comprising:

an X-ray source configured to emit X-rays that are received by the PCDs.

16. A computed tomography (CT) imaging apparatus, comprising:

a plurality of detectors, each detector being arranged inside a Faraday cage having a plurality of voltage-biased side electrodes arranged on at least one side surface of the Faraday cage.

17. The apparatus of claim 16 , wherein the detectors include photon counting detectors (PCDs).

18. The apparatus of claim 16 , wherein the side electrodes are arranged on all four side surfaces on the Faraday cage.

19. The apparatus of claim 17 , wherein each PCD comprises:

a rectangular semiconductor crystal having a first face and a second face, wherein the first face and the second face are parallel;

a cathode side including a cathode electrode covering the first face; and

an anode side including a plurality of anode pixels on the second face.

20. The apparatus of claim 19 , wherein a voltage applied to the voltage-biased side-electrodes decreases from the anode side of the PCD to the cathode side of the PCD.