Delay Circuit Feedback Loop for X-ray Pulse Amplitude
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Solution Overview
Problem
High-speed X-ray photon counting in computer tomography faces challenges due to high noise and reduced signal amplitude caused by short shaping times and the ballistic deficit, which limits the ability to process pulses accurately at high rates.
Innovation Solution
An apparatus and method that incorporate a pre-amplifying element and a shaping element with a feedback loop, where a delay circuit extends the time for charge collection, improving the amplitude of the electrical pulse by delaying the trigger condition for discharging the feedback loop, thereby reducing the ballistic deficit and enhancing signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the shaping time is shortened to increase counting rate, then the productivity is improved, but the signal amplitude decreases and noise increases
Solution Approach 1:
The delay circuit is activated in advance of the normal discharge timing to extend the charge collection period. By preemptively delaying the discharge of the feedback loop, the system allows more time for charge accumulation before the shaping process completes, thereby maintaining higher signal amplitudes even at shortened shaping times and increased counting rates.
2Productivity
If the shaping time is shortened to process pulses at high rates, then the productivity is improved, but the signal-to-noise ratio deteriorates
Solution Approach 1:
The feedback loop in the shaping circuit is equipped with a delay circuit that extends the charge collection time. This feedback mechanism ensures that even when shaping times are reduced for high-rate processing, the feedback path continues to collect and accumulate charge for a longer duration, thereby maintaining the signal-to-noise ratio while enabling higher pulse processing rates.
3Productivity
If the feedback loop discharge time is reduced to increase counting capacity, then the productivity is improved, but the charge collection is incomplete causing ballistic deficit
Solution Approach 1:
The delay circuit is engaged in advance of the feedback loop discharge to extend the charge collection window. By activating the delay mechanism before discharge occurs, the system ensures that charge collection is completed more thoroughly even when the overall shaping time is reduced, thereby eliminating ballistic deficit while maintaining high counting capacity.
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
The solution effectively improves the amplitude and accuracy of electrical pulses, reducing noise and increasing the ability to process pulses at high rates, leading to improved counting performance in X-ray photon detection for medical and imaging applications.
Implementation Method 1
a pre-amplifying element adapted to convert the charge pulse generated by an impinging photon into an electrical signal
Implementation Method 2
a shaping element having a feedback loop and adapted to convert the electrical signal into an electrical pulse, wherein a delay circuit is connected to the feedback loop such that a time during which the feedback loop collects charges of the electrical signal is extended
Implementation Method 3
a delay circuit is connected to the feedback loop such that a time during which the feedback loop collects charges of the electrical signal is extended in order to improve an amplitude of the electrical pulse at an output of the shaping element
Data Source
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AI summary
The present invention relates to an apparatus (10) for generating countable pulses (30) from impinging X-ray photons (12, 14) in an imaging device (16), in particular in a computer tomograph, the apparatus (10) comprising a pre-amplifying element (18) adapted to convert a charge pulse (20) generated by an impinging photon (12, 14) into an electrical signal (22) and a shaping element (26) having a feedback loop (28) and adapted to convert the electrical signal (22) into an electrical pulse (30), wherein a delay circuit (38) is connected to the feedback loop (28) such that a time during which the feedback loop (28) collects charges of the electrical signal (22) is extended in order to improve an amplitude of the electrical pulse (30) at an output (56) of the shaping element (26). The invention also relates to a corresponding imaging device (16) and a corresponding method.