Co-Planar Grid Sensor Depth Measurement Signal Weighting
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Solution Overview
Problem
Co-planar grid sensors for gamma-ray detection face challenges in achieving high resolution due to electron trapping effects, which are not adequately addressed by existing methods that require complex electronics or impractical hardware modifications.
Innovation Solution
A method and device that measure the depth of interaction by calculating the timing difference between the collecting and non-collecting electrode signals, allowing for weighting of the difference signal to improve spectral resolution without adding bulky electronics, using a differential amplifier and comparators to determine the timing difference and calculate the depth of interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cooled sensors are used, then signal to noise ratio is improved, but operational convenience and practicality deteriorate
Solution Approach 1:
The patent changes the operating temperature parameter from cryogenic to room temperature, enabling practical operation while maintaining detection capability through compensated signal processing methods that address the resulting noise increase
2Ease of operation
If co-planar grid sensors operate at room temperature, then operational convenience is improved, but signal to noise ratio deteriorates
Solution Approach 1:
The patent implements feedback through depth-of-interaction measurement and signal compensation algorithms that correct for noise and trapping effects, thereby improving the signal to noise ratio while maintaining room temperature operation
3Measurement precision
If electrode configuration is made sensitive to one charge type, then spectral resolution is improved, but depth independence deteriorates
Solution Approach 1:
The patent segments the charge collection process by using multiple electrodes with different functions: one electrode collects electrons while another collects holes, allowing independent optimization for spectral resolution while using depth information from the segmented collection to maintain depth independence
4Productivity
If electrons travel longer in bulk, then charge collection is improved, but trapping effects increase
Solution Approach 1:
The patent introduces hole collection as an intermediary mechanism that provides an alternative charge collection path, reducing the distance electrons must travel in the bulk and thereby minimizing trapping effects while maintaining overall charge collection efficiency
5Measurement precision
If complex electronics are added to compensate for trapping effects, then spectral resolution is improved, but device complexity increases
Solution Approach 1:
The patent enables the detector system to self-correct for trapping effects by using the inherent depth-of-interaction information from the co-planar grid structure itself, eliminating the need for external complex compensation electronics while achieving high spectral resolution
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 enhances the resolution of gamma-ray detection by compensating for electron trapping effects, achieving high spectral resolution without the need for complex electronics, making it suitable for room-temperature operations and various applications.
Implementation Method 1
the charges, both electrons and holes, generated by the ionizing gamma radiation
Implementation Method 2
the electrons are subject to substantial trapping effects
Implementation Method 3
the induction depends strongly on the electrons
Implementation Method 4
obtaining a difference in time between a time of detection (or arrival) of a charge generated by the event at the collecting electrode and a time of occurrence of the event
Data Source
AI summary
A device and method for measuring a depth of interaction of an ionizing event and improving resolution of a co-planar grid sensor (CPG) are provided. A time-of-occurrence is measured using a comparator to time the leading edge of the event pulse from the non-collecting or collecting grid. A difference signal between the grid signals obtained with a differential amplifier includes a pulse with a leading edge occurring at the time-of-detection, measured with another comparator. A timing difference between comparator outputs corresponds to the depth of interaction, calculated using a processor, which in turn weights the difference grid signal to improve spectral resolution of a CPG sensor. The device, which includes channels for grid inputs, may be integrated into an Application Specific Integrated Circuit. The combination of the device and sensor is included. An improved high-resolution CPG is provided, e.g., a gamma-ray Cadmium Zinc Telluride CPG sensor operating at room temperature.