A local strip adaptive readout method for crossbar anodes

Abstract

This invention provides a local strip adaptive readout method for cross-shaped anodes, addressing the technical problems of existing local strip readout schemes lacking dynamic adjustment capabilities for the spatial distribution characteristics of a single event and struggling to balance flexibility and accuracy under different events. The method first determines the main response strips in the X and Y directions of the current event, then determines the effective response strips in the X and Y directions, and finally reads only the effective response strips in the X and Y directions relevant to the current event to achieve readout for a single event. This invention adaptively adjusts the range of locally effective strips to be read out based on the event response strength, strip distribution, and edge position, reducing the collection of invalid data from the source and avoiding data redundancy.

Description

Technical Field

[0001] This invention relates to a readout method for cross-strip anodes, and more particularly to a local strip adaptive readout method for cross-strip anodes. Background Technology

[0002] Cross-strip anodes are a common two-dimensional readout structure used in position-sensitive detectors, widely applied in single-photon detection, particle detection, and related imaging systems. A cross-strip anode typically consists of two sets of orthogonally arranged strip electrodes (strips), one set acquiring the position information of an event in the X-direction and the other set acquiring the position information in the Y-direction. When an incident particle or photon is multiplied to form an electron cloud and reaches the surface of the cross-strip anode, it causes corresponding charge signals in parts of the strips in the X and Y directions. By reading the response amplitude distribution of the charge signals in the X and Y directions respectively, the two-dimensional position coordinates of the event can be further calculated.

[0003] In the readout system of a cross-strip anode detector, a set of local charge responses formed on the cross-strip anode after a single incident event is typically referred to as an "event." For a single event, the electron cloud does not cover the entire strip, but is usually distributed only on a few adjacent strips within a local area. Therefore, in a single event, only a local strip often carries effective position information, while most other strips do not show a significant response. Strip readout typically involves sampling, measuring, transmitting, and processing the output electrical signals of each strip of the cross-strip anode. Local strip readout, as opposed to uniform acquisition of all strips, selectively reads out only a few local strips relevant to the current event. Adaptive readout means that the range of readout strips is not fixed in advance, but dynamically determined based on the response position, response intensity, or strip distribution of a single event. During position reconstruction, the event position is usually obtained through centroid calculation or other position decoding methods based on the charge signal response amplitude distribution of the local strips. The main response strip is generally the strip with the largest charge signal response amplitude in a single event or the strip that best characterizes the location of the event center; the locally effective strip is generally a number of strips located near the main response strip and jointly participating in the reconstruction of the event location.

[0004] As cross-strip anode detectors evolve towards higher count rates, higher resolutions, and real-time imaging, their readout systems not only need to accurately acquire the charge signals of the strips but also need to minimize invalid data acquisition and shorten the processing time from event occurrence to position output to improve overall system performance. Among existing cross-strip anode detectors, the most common technical solutions are full-strip readout and partial-strip readout. The full-strip readout solution requires connecting all strips in the X and Y directions to front-end amplification, shaping, and sampling circuits respectively, and acquiring the charge signals of each strip through a multi-channel analog-to-digital converter. The acquired multi-channel amplitude data is then sent to the back-end processing unit to complete event recognition, position reconstruction, and image generation. The advantage of this full-strip readout solution is its intuitive implementation, ease of preserving complete event response information, and facilitating subsequent offline analysis and position decoding using various algorithms. However, this solution also has significant problems in practical applications. First, reading out all strips results in significant data redundancy. Since a single event typically affects only a few adjacent strips, synchronous sampling and reading out all strips leads to the collection and transmission of a large amount of strip data that was not involved in the reconstruction of the current event location, significantly increasing the data volume per event. Second, reading out all strips places high demands on front-end hardware resources and back-end data processing capabilities. As the number of crossbar anode strips increases, the amplification, sampling, buffering, and transmission resources required by the system also increase accordingly. This not only increases hardware complexity and system cost but also burdens back-end data processing, hindering continuous operation in high-throughput application scenarios. While local strip readout schemes can reduce invalid data through threshold triggering or channel filtering, they often employ fixed channel selection or fixed range readout methods, lacking the ability to dynamically adjust to the spatial distribution characteristics of individual events. For example, for events at different locations, with varying intensities, or near edge regions, consistently using the same number and range of strips for readout can lead to two problems: first, an excessively large readout range may still contain many invalid strips, failing to effectively reduce the data volume; second, an excessively small readout range may truncate valid signals, affecting the accuracy of location reconstruction. Furthermore, existing local strip readout schemes are often coarse, typically relying on fixed thresholds or fixed grouping structures, making it difficult to balance flexibility and accuracy under different events. Especially under high count rates, adjacent events may be closer in time and space. Without an adaptive local strip determination mechanism for the response distribution of individual events, the invalid readout range can easily increase, even affecting the efficiency of subsequent event identification and location calculation. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of existing local strip readout schemes lacking the ability to dynamically adjust to the spatial distribution characteristics of a single event and being unable to balance flexibility and accuracy under different events, and to provide a local strip adaptive readout method for cross-shaped anodes.

[0006] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0007] A local strip adaptive readout method for cross-strip anodes, characterized by comprising the following steps:

[0008] Step 1: After a single event occurs, the strip with the largest charge signal response amplitude among multiple strips in the X direction is taken as the main response strip in the X direction of the current event, and the strip with the largest charge signal response amplitude among multiple strips in the Y direction is taken as the main response strip in the Y direction of the current event.

[0009] Step 2: Determine the effective response strip in the X direction of the current event based on the attenuation of the charge signal response amplitude of all strips in the X direction relative to the main response strip in the X direction of the current event; determine the effective response strip in the Y direction of the current event based on the attenuation of the charge signal response amplitude of all strips in the Y direction relative to the main response strip in the Y direction of the current event.

[0010] Step 3: Decode the position in the X direction based on the charge signal response amplitude of the effective response strip in the X direction of the current event to obtain the X-direction position coordinates of the current event; decode the position in the Y direction based on the charge signal response amplitude of the effective response strip in the Y direction of the current event to obtain the Y-direction position coordinates of the current event; obtain the two-dimensional position coordinates of the current event based on the X-direction and Y-direction position coordinates, and complete the local strip adaptive readout of a single event.

[0011] Furthermore, step 2 specifically involves:

[0012] Traverse all stripes in the X direction and take all stripes in the X direction that satisfy the following formula as the valid response stripes in the X direction of the current event;

[0013] Q i ≥αQ xk ;

[0014] Among them, Q i Let Q be the charge signal response amplitude of the i-th strip in the X direction, i = 1, 2, ..., P, where P is the number of strips in the X direction; xk Let α be the charge signal response amplitude of the main response strip in the X direction, and α be the preset attenuation threshold coefficient in the X direction, where 0 < α < 1;

[0015] Traverse all stripes in the Y direction and take all stripes in the Y direction that satisfy the following formula as the valid response stripes in the Y direction for the current event;

[0016] Q j ≥βQ yk ;

[0017] Among them, Q j Let Q be the charge signal response amplitude of the j-th strip in the Y direction, where j = 1, 2, ..., L, and L is the number of strips in the Y direction; yk β is the charge signal response amplitude of the main response strip in the Y direction, and β is the preset attenuation threshold coefficient in the Y direction, 0 < β < 1.

[0018] Furthermore, in step 3, a weighted average algorithm is used to perform position decoding in the X direction and position decoding in the Y direction, respectively.

[0019] Furthermore, step 3 specifically involves:

[0020] Step 3.1, calculate the X-axis position coordinates of the current event according to the following formula. :

[0021] ;

[0022] in, Let represent the geometric center coordinates of the i-th effective response strip in the X direction, i = 1, 2, ..., M, where M is the number of effective response strips in the X direction;

[0023] Step 3.2, calculate the Y-axis position coordinates of the current event according to the following formula. :

[0024] ;

[0025] in, Let J be the geometric center coordinates of the j-th effective response strip in the Y direction, where j = 1, 2, ..., N, and N is the number of effective response strips in the Y direction.

[0026] Step 3.3: Set the X-axis position coordinates of the current event. and Y-direction position coordinates By combining these coordinates, the two-dimensional position coordinates of the current event (x, y) can be obtained, thus completing the local strip adaptive readout of a single event.

[0027] Compared with the prior art, the present invention has the following beneficial technical effects:

[0028] 1. This invention provides a local strip adaptive readout method for cross-strip anodes. Addressing the characteristic that a single event in a cross-strip anode only generates a significant charge signal on a local strip, the method first determines the main response strips in the X and Y directions based on the strip charge signal response amplitude. Then, based on the attenuation degree of the charge signal response amplitude of all strips relative to the corresponding main response strips, it determines the effective response strips in the X and Y directions for the current event. Finally, it reads out only the effective response strips in the X and Y directions related to the current event to achieve readout for a single event. This local strip adaptive readout method can adaptively adjust the range of locally effective strips to be read out according to the event response strength, strip distribution, and edge position, reducing the collection of invalid data from the source and thus reducing data redundancy caused by reading out all strips.

[0029] 2. The present invention provides a local strip adaptive readout method for cross-strip anodes, which is simple and convenient. When facing real-time imaging, it effectively improves the efficiency of position reconstruction and imaging processing while adaptively adjusting the local effective strip range to be read out. It can be widely used in various cross-strip anode detectors. Attached Figure Description

[0030] Figure 1 This is a flowchart of a local strip adaptive readout method for cross-shaped strip anodes according to the present invention;

[0031] Figure 2 This is a schematic diagram of the local effective strip range in the X direction of the current event determined in step 2 of this embodiment of the invention;

[0032] Figure 3 This is a schematic diagram of the asymmetric local effective strip range formed in step 2 of the present invention. Detailed Implementation

[0033] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0034] A local strip adaptive readout method for cross-strip anodes, such as Figure 1 As shown, it includes the following three steps:

[0035] Step 1: Determine the main response stripe in the X direction and the main response stripe in the Y direction for the current event.

[0036] After a single event occurs, charge signals with different amplitudes will be generated on the strips in the X and Y directions of the cross-shaped anode. Since the charge signal response amplitude of the strips near the center of the electron cloud is usually larger, while the charge signal response amplitude of the strips far from the center of the electron cloud gradually decreases, the main response strips in the X and Y directions of the current event can be determined based on the charge signal response amplitude of the strips.

[0037] Taking the X direction as an example, suppose there are P stripes in the X direction. The strip with the largest charge signal response amplitude among the P stripes in the X direction is taken as the main response strip in the X direction for the current event. The charge signal response amplitudes of the P strips are denoted as Q1, Q2, ..., Q... P Then the charge signal response amplitude Q of the main response strip in the X direction of the current event k =max(Q1,Q2,…,Q P ).

[0038] Using the same method, the strip with the largest charge signal response amplitude among multiple strips in the Y direction is taken as the main response strip in the Y direction for the current event.

[0039] Step 2: Determine the valid response strips in the X and Y directions for the current event.

[0040] After determining the main response stripe in the X direction and the main response stripe in the Y direction of the current event, the effective response stripe in the X direction and the effective response stripe in the Y direction of the current event are determined with the main response stripe in the X direction and the main response stripe in the Y direction as the center, respectively.

[0041] The determination of effective response strips is based on the following: Since the charge signal response amplitude of the strips on both sides of the main response strip gradually decreases as the distance between them and the main response strip increases, it can be determined whether they still belong to the effective response strips of the current event based on the degree of attenuation of the charge signal response amplitude of all strips in the corresponding direction relative to the main response strip in the current direction.

[0042] Taking the X direction as an example, all strips in the X direction (including the main response strip in the X direction) are traversed. If the charge signal response amplitude of the current strip is greater than or equal to a set amplitude threshold, then the current strip is considered to belong to the local effective strip range in the X direction of the current event and is used as the effective response strip in the X direction of the current event. If the charge signal response amplitude of the current strip is less than the set amplitude threshold, then the current strip is considered not to belong to the local effective strip range in the X direction of the current event, and its contribution to the position decoding of the current event is small or non-existent. Therefore, the current strip is not used as the effective response strip in the X direction of the current event. Figure 2As shown, the position between the two blue dashed lines is the local effective strip range in the X direction of the current event. All strips within the local effective strip range in the X direction are effective response strips in the X direction. In this embodiment, the number of effective response strips in the X direction is five.

[0043] If only a few stripes on both sides of the main response strip in a certain direction satisfy the condition, the local effective strip range is small. If more stripes on both sides satisfy the condition, the local effective strip range increases accordingly. If the main response strip in a certain direction is located at the edge region of the intersecting strip anode, the expansion of the local effective strip range on one side of the boundary is restricted. In this case, it only continues to expand according to the above rules on the side where adjacent stripes exist, forming an asymmetric local effective strip range, such as... Figure 3 As shown, the area between the two blue dashed lines represents the asymmetric local effective stripe range in that direction for the current event. This demonstrates that the size of the local effective stripe automatically adjusts according to the actual response distribution of the current event, exhibiting adaptive characteristics.

[0044] Specifically, traverse all stripes in the X direction and take all stripes in the X direction that satisfy formula (1) as the valid response stripes in the X direction of the current event;

[0045] Q i ≥αQ xk (1)

[0046] Among them, Q i Let Q be the charge signal response amplitude of the i-th strip in the X direction, i = 1, 2, ..., P, where P is the number of strips in the X direction; xk Let α be the charge signal response amplitude of the main response strip in the X direction, and α be a preset attenuation threshold coefficient in the X direction, where 0 < α < 1; αQ xk This refers to the amplitude threshold set in the X direction.

[0047] Traverse all stripes in the Y direction and take all stripes in the Y direction that satisfy formula (2) as the valid response stripes in the Y direction of the current event;

[0048] Q j ≥βQ yk (2)

[0049] Among them, Q j Let Q be the charge signal response amplitude of the j-th strip in the Y direction, where j = 1, 2, ..., L, and L is the number of strips in the Y direction; yk βQ represents the charge signal response amplitude of the main response strip in the Y direction, where β is the preset attenuation threshold coefficient in the Y direction, 0 < β < 1; yk This refers to the amplitude threshold set in the Y direction.

[0050] Step 3: Obtain the two-dimensional position coordinates of the current event.

[0051] After determining the local effective stripe ranges in the X and Y directions, position decoding in the X and Y directions can be achieved solely using the charge signal response amplitudes of the stripes within these two local effective stripe ranges. Specifically, based on the charge signal response amplitudes of the effective response stripes in the X and Y directions for the current event, position decoding in the X and Y directions is performed respectively, thereby obtaining the two-dimensional position coordinates of the current event. Preferably, for ease of implementation, this embodiment employs a weighted average algorithm to achieve position decoding in both the X and Y directions.

[0052] Based on formula (3), the X-direction position decoding is performed, and the X-direction position coordinates of the current event are calculated. :

[0053] (3)

[0054] in, Let represent the geometric center coordinates of the i-th effective response strip in the X direction, i = 1, 2, ..., M, where M is the number of effective response strips in the X direction.

[0055] Based on formula (4), the position decoding in the Y direction is performed, and the position coordinates in the Y direction of the current event are calculated. :

[0056] (4)

[0057] in, Let J be the geometric center coordinates of the j-th effective response strip in the Y direction, where j = 1, 2, ..., N, and N is the number of effective response strips in the Y direction.

[0058] In the above calculation process, the geometric center coordinates of the strip are used as the position weight coordinates, and the charge signal response amplitude of the strip is used as the weighting coefficient. Since the charge signal response amplitude of the strip closer to the center of the electron cloud is larger, it occupies a larger weight in the position calculation, thus obtaining a more accurate event position.

[0059] Set the X-axis position coordinates of the current event Position coordinates in the Y direction By combining these coordinates, the two-dimensional position coordinates (x, y) of the current event can be obtained, thus completing the local strip adaptive readout of a single event.

[0060] After obtaining the two-dimensional position coordinates of the current event, the calculation results of the current event are output to the host computer. The output includes the number of the main response strips in the X and Y directions, the range of the local effective strips in the X and Y directions, the charge signal response amplitude corresponding to the effective response strips in the X and Y directions, and the finally calculated two-dimensional position coordinates.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A local strip adaptive readout method for a crossbar anode, characterized in that, Includes the following steps: Step 1: After a single event occurs, the strip with the largest charge signal response amplitude among multiple strips in the X direction is taken as the main response strip in the X direction of the current event, and the strip with the largest charge signal response amplitude among multiple strips in the Y direction is taken as the main response strip in the Y direction of the current event. Step 2: Determine the effective response strip in the X direction of the current event based on the attenuation of the charge signal response amplitude of all strips in the X direction relative to the main response strip in the X direction of the current event; determine the effective response strip in the Y direction of the current event based on the attenuation of the charge signal response amplitude of all strips in the Y direction relative to the main response strip in the Y direction of the current event. Step 3: Decode the position in the X direction based on the charge signal response amplitude of the effective response strip in the X direction of the current event to obtain the X-direction position coordinates of the current event; decode the position in the Y direction based on the charge signal response amplitude of the effective response strip in the Y direction of the current event to obtain the Y-direction position coordinates of the current event; obtain the two-dimensional position coordinates of the current event based on the X-direction and Y-direction position coordinates, and complete the local strip adaptive readout of a single event.

2. The method of claim 1, wherein the local strip adaptive readout for a crossbar anode is characterized by, Step 2 is as follows: Traverse all stripes in the X direction and take all stripes in the X direction that satisfy the following formula as the valid response stripes in the X direction of the current event; Q i ≥αQ xk ; wherein Q i is the charge signal response amplitude of the i-th strip in the X direction, i = 1, 2, … P, P being the number of strips in the X direction; Q xk is the charge signal response amplitude of the main response strip in the X direction, and a is a preset X direction attenuation threshold coefficient, 0 < a < 1. Traverse all stripes in the Y direction and take all stripes in the Y direction that satisfy the following formula as the valid response stripes in the Y direction for the current event; Q j ≥βQ yk ; wherein Q j is the charge signal response amplitude of the jth strip in the Y direction, j = 1, 2, … L, L is the number of strips in the Y direction; Q yk is the charge signal response amplitude of the main response strip in the Y direction, and β is a preset Y direction attenuation threshold coefficient, 0 < β < 1.

3. The local strip adaptive readout method for cross-strip anodes according to claim 2, characterized in that: In step 3, a weighted average algorithm is used to perform position decoding in the X direction and position decoding in the Y direction, respectively.

4. The method of claim 3, wherein the local strip adaptive readout for a crossbar anode is characterized by, Step 3 specifically involves: Step 3.1 Calculate the X-direction position coordinate of the current event according to the following formula : ； wherein, is the coordinate of the geometric center position of the i-th effective response strip in the X direction, i = 1, 2, …, M, and M is the number of effective response strips in the X direction; Step 3.2, calculate the Y direction position coordinate of the current event according to the following formula : ； wherein, is the coordinate of the geometric center position of the jth effective response strip in the Y direction, j = 1, 2, … N, and N is the number of effective response strips in the Y direction; Step 3.3: Set the X-axis position coordinates of the current event. and Y-direction position coordinates By combining these coordinates, the two-dimensional position coordinates of the current event (x, y) can be obtained, thus completing the local strip adaptive readout of a single event.

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