Online cluster reconstruction method, device and equipment for high count rate twin-TPC

Abstract

The present invention discloses an online cluster reconstruction method, device and equipment of a high counting rate twin-TPC, the method comprising: generating a reference window based on a front-end data packet collected by the twin-TPC, and caching the reference window information and corresponding pulse data to a RAM according to the generated reference window; performing adjacent window merging, reference window shunting and reference window merging processing in the boundary area of ​​adjacent time windows within the data packet; based on each reference window after processing and the corresponding pulse information, using the "first rise and then fall" trend to find the cluster center channel, and screening out the effective pulse information near the cluster center channel; based on the effective pulse information, using the center of gravity method to restore the position information of the incident particles, and realizing online reconstruction of the cluster. The present invention can be widely used in the field of nuclear detection, especially in the future radioactive nuclear beam physics experiments carried out on advanced high-current heavy ion accelerator devices.

Description

Technical Field

[0001] The present invention relates to an online cluster reconstruction method, device and equipment of high counting rate twin-TPC, and relates to the field of detectors. Background Art

[0002] At high counting rates, there is a high probability of "first come, first served" in the readout signals between different particles, resulting in timing disorder, so twin-TPC is selected as a position-sensitive detector. Two "thin" TPCs with exactly the same detector configuration and close distance are placed upside down to form a set of twin-TPCs. By processing the raw data obtained by electronics, the incident position and drift time information of the particles in the two TPC detectors are obtained respectively. After that, the particle track reconstruction is completed by matching the two TPC events, and the true order of the incident particles is restored, which effectively solves the problem of particle timing disorder at high counting rates (10MHz) and can also eliminate invalid data. Only saving the reconstructed particle information can greatly reduce the pressure of data transmission and storage, making the system have the characteristics of high counting rate and low data volume.

[0003] Due to the phenomenon of particle multiplicity, an incident particle will generate an induction signal (referred to as a cluster) on multiple readout pads (or readout strips). The key to track reconstruction is to restore the position information of the incident particle through cluster reconstruction. Traditional TPC often uses two-dimensional pad readout, and reconstructs clusters through curve fitting to obtain the projection of the particle track on the xy plane, and then combines drift time measurement to reconstruct the three-dimensional track of the particle. However, twin-TPC is very "thin" and uses one-dimensional strip readout. The curve fitting method is no longer applicable. Therefore, how to reconstruct the hitting cluster from massive data to restore the original incident position of the particle becomes a difficulty in twin-TPC track reconstruction. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, in view of the above problems, the purpose of the present invention is to provide a method, device and equipment for online cluster reconstruction of high counting rate twin-TPC that can avoid complicated data sorting operations and save storage resources.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides an online cluster reconstruction method for high count rate twin-TPC, the method comprising:

[0007] Generate a reference window based on the front-end data packets collected by twin-TPC, and cache the reference window information and corresponding pulse data into RAM according to the generated reference window;

[0008] Merge adjacent windows within the data packet, split reference windows, and merge reference windows in the boundary area of ​​adjacent time windows;

[0009] Based on each processed reference window and the corresponding pulse information, the “first rise and then fall” trend is used to find the cluster center channel, and the effective pulse information near the cluster center channel is screened out;

[0010] Based on the effective pulse information, the center of gravity method is used to restore the position information of the incident particles and realize online reconstruction of clusters.

[0011] In some preferred embodiments, a reference window is generated based on the front-end data packets collected by twin-TPC, and pulse data is cached to a RAM partition according to the generated reference window, including:

[0012] The first two-dimensional reference window and the two-dimensional reference window range are established with the first valid pulse information;

[0013] Initialize the total number of windows in the data packet refWindow_num to 1, the effective data depth dataNum[0] in the window to 1, and store the pulse information in the first partition of the data RAM, which is the first-level cache;

[0014] If the second valid pulse information is still within the two-dimensional reference window, the reference window is modified according to the time information and channel information of the pulse, and dataNum[0] is modified to 2, and the pulse information is stored in the first partition of the data RAM; if the second valid pulse information is not within the two-dimensional reference window, a new reference window is added, refWindow_num is modified to 2, dataNum[1] is set to 1, and the information is stored in the second partition of the data RAM;

[0015] Compare the third valid pulse information with the first two reference windows in turn. If it can be attributed to one of them, modify the reference window and the effective data depth. If not, add a new window, modify the total number of windows, set the effective data depth of the new window to 1, and store the pulse information in the corresponding partition of the data RAM; and so on, traverse all the valid pulse information in a single front-end data packet in turn according to the above rules.

[0016] In some preferred embodiments, each RAM group includes 2 data RAMs-dataRAM and 1 reference window RAM-refRAM, refRAM is used to store complete reference window information in each time window, each reference window information includes storage address, valid data depth, minimum channel, maximum channel, minimum time and maximum time; dataRAM is used to store valid pulse information, and several partitions are reserved, each partition is used to store the valid data depth and all valid pulse information in a reference window.

[0017] In some preferred embodiments, adjacent window merging, reference window splitting and reference window merging of boundary areas of adjacent time windows are performed, including:

[0018] Merge adjacent windows: read the first reference window information in refRAM, and compare it with the remaining reference window information one by one. If the time difference and channel difference of the two windows are less than the set threshold, merge the windows, and take the smaller value of the minimum channel and minimum time of the new window, and the larger value of the maximum channel and maximum time of the new window. Take out the valid pulse information in the dataRAM corresponding to the window, sort it in channel order, and rewrite it to the corresponding partition of dataRAM; if the first reference window is compared with all the remaining reference windows, take out the second reference window to start the second round of comparison, and compare it with the remaining reference windows in turn until all windows are compared. At this point, all reference windows in a time window have been fixed;

[0019] Reference window splitting: read the reference window information of refRAM in the first-level cache and make judgments, record the window information close to the time window boundary area and store it directly in the register group, and store the valid pulse information corresponding to other reference windows directly in the second-level cache to find the cluster center channel;

[0020] Merge the reference windows of the boundary area of ​​adjacent time windows: read the data in the register group, take out the first reference window of the boundary area of ​​the first time window as the reference window, and compare it with the reference window of the boundary area of ​​the second time window in turn. If the time difference and channel difference of the two windows are both less than the merging threshold, the windows are merged, and the minimum channel and minimum time of the new window take the smaller value of the two windows, and the maximum channel and maximum time take the larger value of the two windows. Take out the valid pulse information in the dataRAM corresponding to the window, sort it according to the channel order, and rewrite it into the second-level cache; if it cannot be merged, copy the valid pulse information in the dataRAM corresponding to the reference window directly to the second-level cache; according to the above rules, complete the window merging operation of the boundary area of ​​adjacent time windows in turn.

[0021] In some preferred embodiments, based on each processed reference window and the corresponding pulse information, the "first rise and then fall" trend is used to find the central channel of the cluster, including: all valid pulse information in the reference windows are arranged in channel order, and the channel where the energy peak in each window is located is found according to the "first rise and then fall" trend and recorded as a candidate channel; if there is only one candidate channel, it is directly used as the central channel of the cluster; if there are two or more candidate channels, the channel difference and the corresponding time difference between the candidate channels are calculated. If both are less than the threshold, it is considered that the candidate channels belong to the same cluster, and the candidate channel corresponding to the larger energy value is taken as the central channel of the cluster.

[0022] In some preferred embodiments, the position information of the incident particles is restored by the gravity method based on the effective pulse information to achieve online reconstruction of clusters, including: in each cluster information, the impact position of the incident particle in the readout direction is calculated by the gravity method formula :

[0023] ;

[0024] In the formula, For the i Electronic readout channel number, is the energy value of the corresponding channel.

[0025] In some preferred embodiments, a multi-pipeline parallel strategy is used to perform the "generate reference window" operation, and valid pulse information is alternately written into multiple RAM groups, specifically:

[0026] Several front-end boards are provided, and the data packets of the several front-end boards execute the reference window generation operation in parallel within the set multiple time windows, and write the effective pulse information into multiple RAM groups alternately, and two dataRAMs are used in each RAM group for "ping-pong" reading and writing.

[0027] In some preferred embodiments, a multi-pipeline parallel strategy is used to perform the "reference window generation" operation, and the valid pulse information is alternately written into multiple RAM groups. Specifically, 4 front-end boards are provided, and the data packets of the 4 front-end boards perform the reference window generation operation in parallel within 8 time windows, and the valid pulse information is alternately written into 4 RAM groups, and 2 dataRAMs are used in each RAM group for reading and writing:

[0028] In the T0 time window, the 0th data packet of the 0th front-end board performs the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0;

[0029] In the T1 time window, the first data packet of the front-end board No. 0 performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM group 1. At the same time, the 0th data packet of the front-end board No. 1 performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0.

[0030] In the T2 time window, the 2nd data packet of the No. 0 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 2. At the same time, the 1st data packet of the No. 1 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 1. The 0th data packet of the No. 2 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0... and so on. In the T4 time window, the 4th data packet of the No. 0 front-end board continues to execute the "generate reference window" operation and writes the valid pulse information into the 2# data RAM of RAM group 0. At this time, the 0th data packets of the four front-end boards have all completed the "generate reference window" operation, and all valid pulse information has been written into the 1# data RAM of RAM group 0 in channel order.

[0031] In a second aspect, the present invention further provides an online cluster reconstruction device for high counting rate twin-TPC, the device comprising:

[0032] A reference window generating unit is configured to generate a reference window based on the front-end data packet collected by the twin-TPC, and cache the reference window information and the corresponding pulse data to the RAM according to the generated reference window;

[0033] A window merging unit is configured to perform adjacent window merging, reference window splitting and reference window merging processing in the boundary area of ​​adjacent time windows within a data packet;

[0034] The cluster channel unit is configured to find the cluster center channel based on each processed reference window and the corresponding pulse information by using the "first rise and then fall" trend, and filter out the valid pulse information near the cluster center channel;

[0035] The cluster reconstruction unit is configured to restore the position information of the incident particles using the center of gravity method based on the effective pulse information to achieve online reconstruction of the clusters.

[0036] In a third aspect, the present invention further provides an electronic device, comprising:

[0037] at least one processor; and

[0038] A memory communicatively connected to the processor; wherein,

[0039] The memory stores instructions executable by the processor, and the instructions are executed by the processor to enable the processor to perform any one of the methods described above.

[0040] The present invention adopts the above technical solution, and has the following characteristics:

[0041] 1. The present invention performs reference window generation operations on all front-end board data packets in the same time window in spatial order, and stores valid pulse information and reference window information in the same RAM group, thereby avoiding frequent data reading, writing and moving operations and cross-packet merging processing of reference windows in the spatial dimension.

[0042] 2. The present invention adopts a multi-pipeline parallel strategy, that is, the front-end board data executes the "reference window generation" operation in parallel, and writes the effective pulse information into multiple RAM groups alternately, thereby achieving higher parallelism and faster processing speed, and greatly reducing system dead time.

[0043] 3. If all front-end board data are sorted by time before scanning, although the delay can be reduced, the cache of the intermediate results of time sorting not only takes up a large amount of storage resources, but also disrupts the channel order of the data. When subsequently searching for the cluster center channel, it is necessary to re-sort the data according to the channel order. The present invention uses a two-dimensional variable reference window-based method to scan data, which effectively avoids complicated data sorting operations and saves a large amount of FPGA logic resources and storage resources.

[0044] 4. All functions of the present invention are implemented in modular design, and a digital logic implementation scheme is provided, which improves the reusability of the code and facilitates subsequent function expansion and transplantation, and has a certain promoting effect on the technical development of related fields.

[0045] In summary, the present invention can be widely used in the field of nuclear detection, especially in radioactive nuclear beam physics experiments to be carried out on advanced high-current heavy ion accelerator devices in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0047] Figure 1 The front-end board data packet format of some embodiments of the present invention;

[0048] Figure 2 A schematic diagram of a process flow of an online cluster reconstruction method of high count rate twin-TPC in some embodiments of the present invention;

[0049] Figure 3 Performing a "generate reference window" operation in parallel for the four front-end board data of some embodiments of the present invention and writing valid pulse information alternately into the four RAM groups;

[0050] Figure 4A RAM group data format description for some embodiments of the present invention;

[0051] Figure 5 The electronic device structure diagram of some embodiments of the present invention. DETAILED DESCRIPTION

[0052] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0053] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0054] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0055] How to reconstruct the hit clusters from massive data to restore the original incident position of the particles has become a difficulty in twin-TPC track reconstruction. The online cluster reconstruction method, device and equipment of high counting rate twin-TPC provided by the present invention include: generating a reference window based on the front-end data packet collected by twin-TPC, and caching the reference window information and corresponding pulse data to RAM according to the generated reference window; performing adjacent window merging, reference window shunting and reference window merging processing in the boundary area of ​​adjacent time windows; based on each processed reference window, using the "first rise and then fall" trend to find the cluster center channel, and screen out the effective pulse information near the cluster center channel; based on the effective pulse information, using the center of gravity method to restore the position information of the incident particles, and realize cluster online reconstruction. Therefore, the present invention adopts a two-dimensional variable reference window-based method to scan data, effectively avoiding complicated data sorting operations and saving a lot of logical resources and storage resources.

[0056] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0057] Since TPC has many readout electronic channels, it usually adopts the front-end board + subsystem summary board structure. The front-end board integrates dozens or even hundreds of readout channels. In order to reduce the header overhead, the description information and valid pulse information of all channels in the same time window (the time window is a fixed time interval, that is, a packaging operation is performed every fixed time interval, and the data within the time interval is packaged into a data packet) can be used as the payload, plus the header and tail to form a front-end data packet. The specific format is as follows: Figure 1 As shown, the front-end data packet includes a header, a payload and a tail. For example, the header may include a flag, a coarse timestamp and the number of valid pulses, and the payload is sorted in two dimensions of space (channel order) and time. The subsystem summary board receives data from multiple front-end boards through a high-speed interface to achieve detector-level data aggregation and processing. Since cluster reconstruction requires the acquisition of all electronic readout channel data, it can be implemented in the FPGA of the subsystem summary board, taking this as an example, but not limited to this.

[0058] Embodiment 1: Figure 2 As shown, the online cluster reconstruction method of high counting rate twin-TPC provided in this embodiment includes:

[0059] S1. Based on twin-TPC, the front-end data is collected, and a two-dimensional variable reference window is used to scan the data packets of all front-end boards in the same time window in spatial order to generate a reference window, and the generated reference window and corresponding pulse data are cached to RAM.

[0060] In this embodiment, while the data packet of the front-end board is unpacked on the aggregation board, the FPGA is used to sequentially scan the valid pulse information to generate a reference window, wherein the scanning process is:

[0061] S11. Use the first valid pulse information to establish the first two-dimensional reference window ({minimum channel (minChnl), maximum channel (maxChnl), minimum time (minTime), maximum time (maxTime)}) and the window range of the two-dimensional reference window, wherein the valid pulse information is a minimum signal that can be measured by electronics, that is, a valid pulse, characterized by the peak corresponding time information and peak energy information of the valid pulse. The window range of the two-dimensional reference window is based on the two-dimensional reference window, and it is considered to belong to the window range within ± the merging threshold, that is: the channel number interval {minimum channel-spatial merging threshold, maximum channel+spatial merging threshold} and the time interval {minimum time-time merging threshold, maximum time+time merging threshold}.

[0062] S12. Initialize the total number of windows (refWindow_num) in the data packet to 1, the effective data depth (dataNum[0]) in the window (depth refers to the number of valid data in the corresponding reference window) to 1, and store the pulse information in the first partition of the data RAM (dataRAM) (this is the first-level cache).

[0063] S13. If the second valid pulse information is still within the window range of the two-dimensional reference window, modify the reference window according to the time information and channel information of the pulse (the minimum channel and the minimum time are the smaller values ​​of the reference window and the second valid pulse, and the maximum channel and the maximum time are the larger values ​​of the reference window and the second valid pulse), and modify dataNum[0] to 2. The pulse information is stored in the first partition of the data RAM.

[0064] S14. If the second valid pulse information is not within the window range of the two-dimensional reference window, a new reference window is added, refWindow_num is modified to 2, dataNum [1] is set to 1, and the information is stored in the second partition of the data RAM.

[0065] S15. Compare the third valid pulse information with the first two reference windows in turn. If it can be attributed to one of them, modify the reference window and the effective data depth. If not, add a new window, modify the total number of windows, set the effective data depth of the new window to 1, and store the pulse information in the corresponding partition of the data RAM.

[0066] S16. All valid pulse information in a single front-end data packet is traversed in sequence according to the above rules.

[0067] Furthermore, if Figure 4 The data format of the RAM group is as follows: Each RAM group contains 2 dataRAMs and 1 refRAM. The refRAM is used to store the complete reference window information (refWindow) in each time window. The reserved depth is 50, for example, which means that up to 50 reference window information can be stored. Each reference window information includes the storage address (address), effective data depth (dataNum), minimum channel (minChnl), maximum channel (maxChnl), minimum time (minTime) and maximum time (maxTime). The dataRAM is used to store effective pulse information. 50 partitions (refWindow_datablock) are reserved. Each partition is used to store the effective data depth (dataNum) and all effective pulse information (data, including the electronic channel number (ChnlID), time information (Time) and energy information (Energy)) in a reference window.

[0068] In summary, since all front-end board data in the same time window correspond to the same batch of clusters, in order to avoid frequent data reading and writing operations and spatial cross-packet merging processing, the data packets of all front-end boards in the same time window are sequentially subjected to the above-mentioned reference window generation operation in spatial order. The valid pulse information corresponding to each reference window obtained is also cached in the corresponding partition in the data RAM in spatial order, and after the scan is completed, all reference windows are written into the reference window RAM (refRAM) in the order of their appearance.

[0069] S2. Merge adjacent windows within the data packet.

[0070] In this embodiment, step S1 is to divide the window in two dimensions of time and space. It is possible that the valid pulse information belonging to the same cluster is divided into two different reference windows. Therefore, it is necessary to perform an intra-packet window merging operation. The specific process is as follows:

[0071] S21, read the first reference window information in refRAM, and compare it with the remaining reference window information one by one. If the time difference and channel difference of the two windows are both less than the merging threshold, merge the windows, and take the smaller value of the minimum channel and the minimum time of the new window as the minimum value of the two windows, and take the larger value of the maximum channel and the maximum time as the maximum value of the two windows. Then take out the valid pulse information in the dataRAM corresponding to the window, sort it according to the channel order, and rewrite it into the corresponding partition of the dataRAM;

[0072] S22. If the first reference window has been compared with all the remaining reference windows, the second reference window is taken out to start a second round of comparison, and is compared with the remaining reference windows in turn until all the windows have been compared. At this point, all the reference windows in a time window have been fixed.

[0073] S3, reference window diversion.

[0074] In this embodiment, since the detector data is streamed, it is possible that the same cluster information appears in different time windows (data packets), so the reference window near the time window boundary area needs to be merged across packets, and this area usually accounts for a small proportion relative to the entire data packet. Therefore, in order to avoid useless operations and improve timeliness, the reference window information can be diverted, the reference window information of the refRAM in the first-level cache is read and judged, and the window information near the time window boundary area (the start and end time of the time window) is directly stored in the register group to participate in the reference window cross-packet merging operation; and the valid pulse information corresponding to the reference window in the remaining area is directly stored in the second-level cache to find the cluster center channel.

[0075] S4. Reference window cross-packet merging: complete the reference window merging of the boundary area of ​​adjacent time windows.

[0076] In this embodiment, the data in the register group is read, and the first reference window in the first time window boundary area is taken out as the reference window, and it is compared with the reference window in the second time window boundary area in turn. If the time difference and channel difference of the two windows are both less than the merging threshold, the windows are merged, and the minimum channel and minimum time of the new window are taken as the smaller value of the two windows, and the maximum channel and maximum time are taken as the larger value of the two windows. The valid pulse information in the dataRAM corresponding to the window is taken out, sorted in channel order, and written into the second-level cache; if it cannot be merged, the valid pulse information in the dataRAM corresponding to the reference window is directly copied to the second-level cache. According to the above rules, the window merging operation of the adjacent time window boundary areas is completed in turn.

[0077] S5. Find the cluster center channel: Based on the reference window and corresponding pulse data in the second-level cache, use the "first rise and then fall" trend to find the cluster center channel.

[0078] In this embodiment, the reference window obtained by the above operation usually contains only one cluster information, a small part contains two cluster information, and a very small part contains three cluster information. The central channel of each cluster has the largest energy value relative to other channels. Therefore, the channel where the energy peak in each window is located (abbreviated as candidate channel) can be found based on the "first rise and then fall" trend (all valid pulse information in the reference window is arranged in channel order). If there is only one candidate channel, it is directly used as the central channel of the cluster; if there are two or more candidate channels, the channel difference and the corresponding time difference between the candidate channels are calculated. If both are less than the threshold, it is considered that the candidate channels belong to the same cluster, and the candidate channel corresponding to the larger energy value is taken as the central channel of the cluster.

[0079] S6. Cluster boundary detection: filter out the effective pulse information near the cluster center channel.

[0080] In this embodiment, if there is only one central channel in the reference window, the spatial distance (channel difference) between the effective pulse information in the window and the central channel of the cluster and the corresponding time difference are calculated. If the time difference and the channel difference are both less than the threshold, the center of gravity method is used; if there are two or more central channels in the reference window, the effective pulse information in the window is assigned to the cluster with the closest distance (time distance and spatial distance).

[0081] Furthermore, since the weights of time and space are different, the distance is normalized, as shown in formula (1):

[0082] (1).

[0083] in, is the corresponding time difference of the two central channels, T is the reference window merging time threshold, is the channel difference between the two central channels, and N is the particle multiplicity value (i.e., the maximum number of electronic channels that a single incident particle can hit).

[0084] S7. Use the center of gravity method to restore the position information of the incident particles.

[0085] In this embodiment, the purpose of cluster reconstruction is to reconstruct the incident position information of the particle. Through the above S1-S6 operations, the effective pulse information belonging to the same cluster is found, and finally the position information of the incident particle is restored using the centroid method. In each cluster information, the centroid method formula (2) is used to calculate the impact position of the incident particle in the X (readout bar) direction ( ):

[0086] (2).

[0087] in, For the i Electronics read out channel number, is the energy value of the corresponding channel.

[0088] In some possible implementations, the entire process described above can implement pipeline operation, but the front-end board data packets are generated in parallel, while the "generate reference window" stage is executed serially, which greatly increases the system dead time. Therefore, in order to achieve higher parallelism and faster processing speed, the present invention adopts a multi-pipeline parallel strategy, that is, the front-end board data executes the "generate reference window" operation in parallel, and writes the valid pulse information alternately into multiple RAM groups. The specific working process is as follows:

[0089] like Figure 3 As shown in the figure, taking 4 front-end boards as an example, the data packets of the 4 front-end boards are executed in parallel in 8 time windows to generate reference window operations, and the valid pulse information is alternately written into 4 RAM groups. In order to avoid read-write conflicts or data overwriting, 2 data RAMs (dataRAM) are used in each RAM group for "ping-pong" reading and writing. In the T0 time window, the 0th data packet of the No. 0 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0; in the T1 time window, the 1st data packet of the No. 0 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 1, and at the same time, the 0th data packet of the No. 1 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0; in the T2 time window, the 2nd data packet of the No. 0 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 2, and at the same time, the 1st data packet of the No. 1 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 1, and the 0th data packet of the No. 2 front-end board executes the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0... and so on, to the T4 time window, the 4th data packet of the No. 0 front-end board continues to execute the "generate reference window" operation and writes the valid pulse information into the RAM In the 2# data RAM of group 0, at this time, the 0th data packets of the four front-end boards have all completed the "generate reference window" operation, and all valid pulse information has been written into the 1# data RAM of RAM group 0 in channel order, and continue to perform operations such as reference window packet merging and reference window diversion.

[0090] In addition, each RAM group also contains a reference window RAM (refRAM) for storing the complete reference window information in each time window. Since each front-end board data packet is only a fragment of the complete data in the time window, only the reference window information generated by the "generate reference window" operation performed by the front-end boards 0-2 is temporarily stored in the register group. Only when the "generate reference window" operation is completed for the data of the front-end board 3, the complete reference window information is written to the reference window RAM. That is, for a specific RAM group, with 4 time windows as a cycle, only 1 time window performs the reference window RAM write operation each time, and the remaining 3 time windows are sufficient to complete the reference window RAM read operation and refresh operation during the reference window packet merging, reference window diversion and other operations.

[0091] Embodiment 2: Embodiment 1 above provides an online cluster reconstruction method for high-counting rate twin-TPC. Correspondingly, this embodiment provides an online cluster reconstruction device for high-counting rate twin-TPC. The device provided in this embodiment can implement the online cluster reconstruction method for high-counting rate twin-TPC in Embodiment 1, and the device can be implemented by software, hardware, or a combination of software and hardware. For the convenience of description, this embodiment is described by dividing the functions into various units and describing them separately. Of course, the functions of each unit can be implemented in the same or one or more software and / or hardware during implementation. For example, the device may include integrated or separate functional modules or functional units to execute the corresponding steps in each method of Embodiment 1. Since the device of this embodiment is basically similar to the method embodiment, the description process of this embodiment is relatively simple, and the relevant parts can refer to the partial description of Embodiment 1. The embodiment of the online cluster reconstruction device for high-counting rate twin-TPC provided by the present invention is only schematic.

[0092] Specifically, the embodiment provides an online cluster reconstruction device for high counting rate twin-TPC, the device comprising:

[0093] A reference window generating unit is configured to generate a reference window based on the front-end data packet collected by the twin-TPC, and cache the reference window information and the corresponding pulse data to the RAM according to the generated reference window;

[0094] A window merging unit is configured to perform adjacent window merging, reference window splitting and reference window merging processing in the boundary area of ​​adjacent time windows within a data packet;

[0095] The cluster channel unit is configured to find the cluster center channel based on each processed reference window and the corresponding pulse information by using the "first rise and then fall" trend, and filter out the valid pulse information near the cluster center channel;

[0096] The cluster reconstruction unit is configured to restore the position information of the incident particles using the center of gravity method based on the effective pulse information to achieve online reconstruction of the clusters.

[0097] Embodiment 3: This embodiment provides an electronic device corresponding to the online cluster reconstruction method of high counting rate twin-TPC provided in Embodiment 1. The electronic device may be an electronic device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of Embodiment 1.

[0098] like Figure 5 As shown, the electronic device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Component (EISA) bus, etc. The memory stores a computer program that can be run on the processor. When the processor runs the computer program, it executes the method of Embodiment 1. The implementation principle and technical effect are similar to those of Embodiment 1 and will not be repeated here. Those skilled in the art can understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation on the computing device to which the scheme of the present application is applied. The specific computing device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0099] In a preferred embodiment, the logic instructions in the above-mentioned memory can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), optical disk and other media that can store program codes.

[0100] In a preferred embodiment, the processor may be a central processing unit (CPU), a digital signal processor (DSP) or other general-purpose processors of various types, which are not limited herein.

[0101] Embodiment 4: This embodiment provides a computer-readable storage medium storing one or more programs, wherein the one or more programs include computer instructions. When the computer instructions are executed by a computer, the computer executes the method provided in the above-mentioned embodiment 1.

[0102] Embodiment 5: This embodiment provides a computer program product. The computer program product may include a computer program stored on a computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the method provided in the above-mentioned embodiment 1. Its implementation principle and technical effects are similar to those of embodiment 1 and will not be repeated here.

[0103] In a preferred embodiment, the computer-readable storage medium may be a tangible device that holds and stores instructions used by the instruction execution device, such as but not limited to an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination thereof. The computer-readable storage medium stores computer program instructions that cause the computer to execute the method provided in the first embodiment.

[0104] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (apparatus), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0105] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0106] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0107] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In the description of this specification, the description of reference terms "a preferred embodiment", "further", "specifically", "in the present embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradiction.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An online cluster reconstruction method for high count rate twin-TPC, characterized in that: The method includes: Generate a reference window based on the front-end data packets collected by twin-TPC, and cache the reference window information and corresponding pulse data into RAM according to the generated reference window; Merge adjacent windows within the data packet, split reference windows, and merge reference windows in the boundary area of ​​adjacent time windows; Based on each processed reference window and the corresponding pulse information, the "first rise and then fall" trend is used to find the cluster center channel, and the effective pulse information near the cluster center channel is screened out; the process of finding the cluster center channel using the "first rise and then fall" trend is as follows: all the effective pulse information in the reference window is arranged in channel order, and the channel where the energy peak in each window is found according to the "first rise and then fall" trend is recorded as the candidate channel; if there is only one candidate channel, it is directly used as the cluster center channel; if there are two or more candidate channels, the channel difference and the corresponding time difference between the candidate channels are calculated. If both are less than the threshold, it is considered that the candidate channels belong to the same cluster, and the candidate channel corresponding to the larger energy value is taken as the cluster center channel; Based on the effective pulse information, the center of gravity method is used to restore the position information of the incident particles and realize online reconstruction of clusters.

2. The online cluster reconstruction method of high count rate twin-TPC according to claim 1, characterized in that: Generate a reference window based on the front-end data packets collected by twin-TPC, and cache the pulse data to the RAM partition according to the generated reference window, including: The first two-dimensional reference window and the two-dimensional reference window range are established with the first valid pulse information; Initialize the total number of windows in the data packet refWindow_num to 1, the effective data depth dataNum[0] in the window to 1, and store the pulse information in the first partition of the data RAM, which is the first-level cache; If the second valid pulse information is still within the two-dimensional reference window, the reference window is modified according to the time information and channel information of the pulse, and dataNum[0] is modified to 2, and the pulse information is stored in the first partition of the data RAM; if the second valid pulse information is not within the two-dimensional reference window, a new reference window is added, refWindow_num is modified to 2, dataNum[1] is set to 1, and the information is stored in the second partition of the data RAM; Compare the third valid pulse information with the first two reference windows in turn. If it can be attributed to one of them, modify the reference window and the effective data depth. If not, add a new window, modify the total number of windows, set the effective data depth of the new window to 1, and store the pulse information in the corresponding partition of the data RAM; and so on, traverse all the valid pulse information in a single front-end data packet in turn according to the above rules.

3. The online cluster reconstruction method of high count rate twin-TPC according to claim 2, characterized in that: Each RAM group contains 2 data RAMs-dataRAM and 1 reference window RAM-refRAM. RefRAM is used to store the complete reference window information in each time window. Each reference window information includes storage address, effective data depth, minimum channel, maximum channel, minimum time and maximum time. The dataRAM is used to store valid pulse information, and several partitions are reserved. Each partition is used to store the valid data depth and all valid pulse information within a reference window.

4. The online cluster reconstruction method of high count rate twin-TPC according to claim 3, characterized in that: Merge adjacent windows, split reference windows, and merge reference windows in the border area of ​​adjacent time windows, including: Merge adjacent windows: read the first reference window information in refRAM, and compare it with the remaining reference window information one by one. If the time difference and channel difference of the two windows are less than the set threshold, merge the windows, and take the smaller value of the minimum channel and minimum time of the new window, and the larger value of the maximum channel and maximum time of the new window. Take out the valid pulse information in the dataRAM corresponding to the window, sort it in channel order, and rewrite it to the corresponding partition of dataRAM; if the first reference window is compared with all the remaining reference windows, take out the second reference window to start the second round of comparison, and compare it with the remaining reference windows in turn until all windows are compared. At this point, all reference windows in a time window have been fixed; Reference window splitting: read the reference window information of refRAM in the first-level cache and make judgments, record the window information close to the time window boundary area and store it directly in the register group, and store the valid pulse information corresponding to other reference windows directly in the second-level cache to find the cluster center channel; Merge the reference windows of the boundary area of ​​adjacent time windows: read the data in the register group, take out the first reference window of the boundary area of ​​the first time window as the reference window, and compare it with the reference window of the boundary area of ​​the second time window in turn. If the time difference and channel difference of the two windows are both less than the merging threshold, the windows are merged, and the minimum channel and minimum time of the new window take the smaller value of the two windows, and the maximum channel and maximum time take the larger value of the two windows. Take out the valid pulse information in the dataRAM corresponding to the window, sort it according to the channel order, and rewrite it into the second-level cache; if it cannot be merged, copy the valid pulse information in the dataRAM corresponding to the reference window directly to the second-level cache; according to the above rules, complete the window merging operation of the boundary area of ​​adjacent time windows in turn.

5. The online cluster reconstruction method of high count rate twin-TPC according to claim 1, characterized in that: Based on the effective pulse information, the center of gravity method is used to restore the position information of the incident particles and realize the online reconstruction of clusters, including: In each cluster information, the center of gravity formula is used to calculate the impact position of the incident particle in the readout direction. : ； In the formula, Read out the channel number for electronics, is the energy value of the corresponding channel.

6. The online cluster reconstruction method of high count rate twin-TPC according to claim 1, characterized in that: The "Generate Reference Window" operation is performed using a multi-pipeline parallel strategy to alternately write valid pulse information into multiple RAM groups, specifically: Several front-end boards are provided, and the data packets of the several front-end boards execute the reference window operation in parallel within the set multiple time windows, and write the valid pulse information alternately into multiple RAM groups, and each RAM group adopts 2 dataRAM "ping-pong" reading and writing.

7. The online cluster reconstruction method of high count rate twin-TPC according to claim 6, characterized in that: A multi-pipeline parallel strategy is used to perform the "reference window generation" operation, and the valid pulse information is alternately written into multiple RAM groups. Specifically, there are 4 front-end boards, and the data packets of the 4 front-end boards perform the reference window generation operation in parallel within 8 time windows, and the valid pulse information is alternately written into 4 RAM groups. Two dataRAMs are used in each RAM group for "ping-pong" reading and writing: In the T0 time window, the 0th data packet of the 0th front-end board performs the "generate reference window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0; In the T1 time window, the first data packet of the front-end board No. 0 performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM group 1. At the same time, the 0th data packet of the front-end board No. 1 performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM group 0. In the T2 time window, the 2nd data packet of the No. 0 front-end board performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM Group 2. At the same time, the 1st data packet of the No. 1 front-end board performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM Group 1. The 0th data packet of the No. 2 front-end board performs the "Generate Reference Window" operation and writes the valid pulse information into the 1# data RAM of RAM Group 0... and so on. In the T4 time window, the 4th data packet of the No. 0 front-end board continues to perform the "Generate Reference Window" operation and writes the valid pulse information into the 2# data RAM of RAM Group 0. At this time, the 0th data packets of the four front-end boards have all completed the "Generate Reference Window" operation, and all valid pulse information has been written into the 1# data RAM of RAM Group 0 in channel order.

8. An online cluster reconstruction device for high count rate twin-TPC, characterized in that: The device includes: A reference window generating unit is configured to generate a reference window based on the front-end data packet collected by the twin-TPC, and cache the reference window information and the corresponding pulse data to the RAM according to the generated reference window; A window merging unit is configured to perform adjacent window merging, reference window splitting and reference window merging processing in the boundary area of ​​adjacent time windows within a data packet; The cluster channel unit is configured to use the "first rise and then fall" trend to find the cluster center channel based on each processed reference window and the corresponding pulse information, and screen out the valid pulse information near the cluster center channel, wherein the process of finding the cluster center channel using the "first rise and then fall" trend is as follows: all valid pulse information in the reference window is arranged in channel order, and the channel where the energy peak in each window is located is found according to the "first rise and then fall" trend and recorded as a candidate channel; if there is only one candidate channel, it is directly used as the cluster center channel; if there are two or more candidate channels, the channel difference and the corresponding time difference between the candidate channels are calculated, and if both are less than the threshold, it is considered that the candidate channels belong to the same cluster, and the candidate channel corresponding to the larger energy value is taken as the cluster center channel; The cluster reconstruction unit is configured to restore the position information of the incident particles using the center of gravity method based on the effective pulse information to achieve online reconstruction of the clusters.

9. An electronic device, characterized in that: include: at least one processor; as well as A memory communicatively connected to the processor; wherein, The memory stores instructions executable by the processor, and the instructions are executed by the processor to enable the processor to perform the method according to any one of claims 1 to 7.

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