Focused Pinhole Gamma Collimator for High-Energy Imaging
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Solution Overview
Problem
Higher energy gamma radiation penetrates the thinnest portions of existing pinhole collimators, leading to unacceptable image definition, and reducing the acceptance angle or increasing device bulkiness are undesirable solutions.
Innovation Solution
The pinhole systems are arranged such that each pinhole has a portion of the focus volume outside its field of view, allowing for smaller acceptance angles while maintaining the central field of view and compactness by using clusters of pinholes with non-parallel central lines, where each pinhole sees only a part of the focus volume, enabling improved image definition without reducing the central field of view or increasing device dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the acceptance angle of the pinhole cones is decreased to improve image definition, then image definition improves, but the central field of view is reduced and the device becomes bulkier
Solution Approach 1:
The patent divides the pinhole system into multiple pinhole systems, each with multiple pinholes that have mutually non-parallel central lines. Each pinhole system covers a specific portion of the focus volume, and the combination of all pinhole systems provides complete coverage. This segmentation allows each pinhole to have a smaller acceptance angle while the overall system maintains the required central field of view through the collective coverage of multiple pinholes.
2Measurement precision
If the acceptance angle of the pinhole cones is decreased to improve image definition, then image definition improves, but the device dimensions increase
Solution Approach 1:
The patent introduces non-parallel central lines for pinholes, utilizing three-dimensional spatial arrangement rather than simple planar configurations. By arranging pinholes with central lines that diverge in different directions in 3D space, the system achieves improved image definition without requiring a proportional increase in device dimensions, as the non-parallel arrangement allows more efficient use of spatial volume.
3Reliability
If higher energy gamma radiation is detected, then detection capability improves, but penetration through pinhole knife edges increases causing image definition to decrease
Solution Approach 1:
The patent segments the detection task across multiple pinholes with non-parallel central lines, so that each pinhole handles a specific angular range. This segmentation reduces the acceptance angle for each individual pinhole, thereby reducing the penetration of high-energy gamma radiation through the pinhole knife edges, while the collective arrangement of all pinholes maintains the required detection capability across the full field of view.
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 arrangement enhances image definition by distributing information over more pinholes, increasing sensitivity, and allowing for higher resolution imaging of high-energy gamma radiation without increasing device size or reducing the central field of view, effectively addressing the penetration issues with high-energy gamma radiation.
Implementation Method 1
a collimator having a plurality of pinhole systems, each pinhole system having a plurality of pinholes having mutually non-parallel central lines
Data Source
Figure 1~2b
Figure 3~5
AI summary
The invention provides a gamma detection device, a collimator for use therein, and use of such a collimator or device in imaging an object. The invention is directed to pinhole imaging with high energy photons, such as 511 keV photons. In order to achieve sufficiently low pinhole knife edge penetration, the collimator uses a plurality of focused clusters of pinholes, each with a smaller opening angle, and arranged such that all the combined fields of view of the individual pinholes in all clusters provide a large central field of view with still compact dimensions of the detection device. This is made possible since the field of view of a single cluster is divided up into a number of individual fields of view.