Edge-On Photon-Counting X-Ray Detector Sub-Module
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Solution Overview
Problem
Current x-ray detectors face challenges in accurately estimating the initial point of interaction of x-ray photons, which limits the resolution and quality of x-ray imaging and image reconstruction.
Innovation Solution
The proposed solution involves a depth-segmented x-ray detector system with edge-on geometry, where detector sub-modules or wafers have detector elements distributed in two directions, including the direction of incoming x-rays, allowing for the estimation of charge diffusion and the initial point of interaction based on the shape and width of the charge cloud, enabling improved resolution by determining the distance between the point of detection and the interaction point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional x-ray detectors are used, then the detector structure is simple, but the resolution and accuracy of initial interaction point estimation is limited
Solution Approach 1:
The detector is divided into multiple depth segments along the direction of incoming x-rays, with detector elements distributed in two directions including the depth direction. This segmentation enables the system to estimate charge diffusion and determine the initial interaction point by analyzing charge cloud characteristics across different depth segments, thereby improving measurement precision without requiring overly complex external systems.
Solution Approach 2:
The patent introduces depth segmentation as an additional dimension to the traditional planar detector structure. By distributing detector elements in two directions (including the depth direction) and analyzing charge diffusion patterns across these dimensions, the system can estimate the initial interaction point with sub-pixel resolution, effectively using dimensional expansion to enhance measurement capability.
2Manufacturing precision
If depth-segmented detector with edge-on geometry is used, then sub-pixel resolution is achieved, but the device complexity increases
Solution Approach 1:
The patent employs edge-on geometry where detector elements are oriented with their sensitive edges facing the incoming x-rays, rather than the conventional face-on configuration. This asymmetric orientation, combined with depth segmentation, enables the system to resolve charge diffusion patterns and estimate initial interaction points with sub-pixel precision, achieving manufacturing precision through geometric asymmetry.
3Measurement precision
If charge diffusion estimation is performed to determine initial interaction point, then imaging resolution is enhanced, but the processing complexity increases
Solution Approach 1:
The detector elements themselves perform the measurement function by detecting charge cloud characteristics and enabling estimation of charge diffusion. The detector structure is designed so that the distributed elements automatically provide the necessary data for initial interaction point estimation through their spatial arrangement and charge collection patterns, reducing the need for external complex processing systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly enhances the resolution of x-ray imaging and image reconstruction, allowing for sub-pixel resolution and improved detection of the initial interaction point, addressing the limitations of existing technologies.
Implementation Method 1
Modern x-ray detectors normally need to convert the incident x-rays into electrons, this typically takes place through photo absorption or through Compton interaction
Implementation Method 2
Modern x-ray detectors normally need to convert the incident x-rays into electrons, this typically takes place through photo absorption or through Compton interaction
Implementation Method 3
The resulting electrons are usually creating secondary visible light until its energy is lost and this light is in turn detected by a photo-sensitive material
Data Source
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AI summary
There is provided a method for enabling estimation of an initial point of interaction of an x-ray photon in a photon-counting x-ray detector, which is based on a number of x- ray detector sub-modules or wafers, each of which comprises detector elements, wherein the x-ray detector sub-modules are oriented in edge-on geometry with the edge directed towards the x-ray source, assuming the x-rays enter through the edge. Each detector sub-module or wafer has a thickness with two opposite sides of different potentials to enable charge drift towards the side, where the detector elements, also referred to as pixels, are arranged. Basically, the method comprises: determining (S1) an estimate of charge diffusion originating from a Compton interaction or an interaction through photoeffect related to the x-ray photon in a detector sub-module or wafer of the x-ray detector; and estimating (S2) the initial point of interaction along the thickness of the detector sub-module based on the determined estimate of charge diffusion.