CN-121995428-A - Three-dimensional track reconstruction method and equipment for muon imaging

CN121995428ACN 121995428 ACN121995428 ACN 121995428ACN-121995428-A

Abstract

The application discloses a three-dimensional track reconstruction method and equipment for muon imaging, and relates to the field of signal detection and ray imaging; the method comprises the steps of carrying out channel waveform analysis on a preprocessed original waveform signal by adopting a waveform identification technology to obtain a channel waveform analysis result, combining a detector-electronics channel mapping table, utilizing a hit continuity characteristic channel cluster to decode continuous channel information, utilizing a space point clustering algorithm to take spatially adjacent electronic signals in continuous clusters as the same electronic cloud cluster based on the continuous channel information, and utilizing a screening reconstruction algorithm to complete three-dimensional track reconstruction based on three-dimensional barycentric coordinates of a plurality of electronic cloud clusters. The application solves the problem of reconstruction ambiguity of small-angle incident muon cases through channel waveform analysis, hit cluster searching and three-dimensional track reconstruction.

Inventors

LIU SHUBIN
WANG TING
WANG YU
FENG CHANGQING
ZHANG ZHIYONG
SHEN ZHONGTAO

Assignees

中国科学技术大学

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. A method for reconstructing a three-dimensional track of a muon image, comprising: acquiring an original waveform signal, wherein the original waveform signal is acquired through a muon imaging system, and the muon imaging system is a muon imaging system based on a time projection room detector; Preprocessing the original waveform signal to obtain a preprocessed original waveform signal; Carrying out channel waveform analysis on the preprocessed original waveform signal by adopting a waveform identification technology to obtain a channel waveform analysis result; based on the channel waveform analysis result and the detector-electronics channel mapping table, utilizing the hit continuity characteristic channel cluster to decode a continuous cluster, and caching continuous channel information; Based on the continuous channel information, using a space point clustering algorithm to take the electronic signals adjacent to the space in the continuous clusters as the same electronic cloud cluster, wherein the three-dimensional coordinates of the electronic signals are determined through the continuous channel information; Obtaining a three-dimensional barycenter coordinate of each electronic cloud cluster through charge weighting; based on the three-dimensional barycentric coordinates of the plurality of electronic cloud clusters, the three-dimensional track reconstruction is completed by using a screening reconstruction algorithm.
2. The three-dimensional track reconstruction method for muon imaging according to claim 1, wherein preprocessing the original waveform signal to obtain a preprocessed original waveform signal, and specifically comprising: performing baseline subtraction processing on the original waveform signal to obtain an intermediate processing signal; And removing high-frequency noise in the intermediate processing signal by adopting a digital filtering technology to obtain a preprocessed original waveform signal.
3. The three-dimensional track reconstruction method for muon imaging according to claim 1, wherein a channel waveform analysis is performed on the preprocessed original waveform signal by using a waveform recognition technology to obtain a channel waveform analysis result, and the method specifically comprises the following steps: Detecting a plurality of local peaks in the preprocessed original waveform signal by using a local maximum method; Based on the peak values of the plurality of local peaks, determining a plurality of independent sub-peak fitting windows by adopting a peak-to-valley minimum point segmentation method; extracting a sub-peak signal corresponding to each independent sub-peak fitting window from the preprocessed original waveform signal; Fitting each sub-peak signal by adopting a preset function to obtain waveform information of a plurality of channels, wherein the channels correspond to the sub-peak signals one by one, and the waveform information comprises the front time and peak amplitude of the sub-peak signals; and screening the waveform information of the channels by adopting a multi-index combined screening method to obtain a channel waveform analysis result.
4. A method for three-dimensional track reconstruction for muon imaging according to claim 3, wherein detecting a plurality of local peaks in the preprocessed raw waveform signal by using a local maxima method comprises: performing peak detection on the preprocessed original waveform signal by using a local maximum method, and determining a peak point based on the central position when the peak characteristic of the platform is detected; upon detection of non-plateau peak features, the peak is determined using parabolic interpolation and parabolic fit.
5. A three-dimensional track reconstruction method for muon imaging according to claim 3, wherein based on said channel waveform analysis result and a detector-electronics channel mapping table, continuous clusters are decoded by utilizing hit continuity feature channel clusters, and continuous channel information is cached, comprising: threshold screening is carried out on the channel based on the peak amplitude information of the channel; importing a detector-electronics channel mapping table; Based on the detector-electronics channel mapping table, the continuous cluster is decoded by utilizing the channel clustering with the characteristic of hit continuity, and continuous channel information is cached, wherein the continuous channel information comprises channel position and time amplitude information of the continuous cluster.
6. A three-dimensional track reconstruction method for muon imaging according to claim 3, wherein based on said continuous channel information, spatially adjacent electronic signals in successive clusters are used as the same electronic cloud by using a spatial point clustering algorithm, comprising: Determining three-dimensional coordinates of electronic signals in the continuous clusters through the continuous channel information, wherein two-dimensional plane coordinates in the three-dimensional coordinates are determined based on channel positions, and longitudinal depth coordinates in the three-dimensional coordinates are obtained based on electronic drift time conversion; Based on three-dimensional coordinates of electronic signals in the continuous cluster, using a space point clustering algorithm to take the electronic signals adjacent to each other in space in the continuous cluster as the same electronic cloud, and introducing physical constraint conditions in the clustering process to obtain a plurality of electronic cloud; The coordinates and the amount of charge of all signal points in the electron cloud are buffered.
7. The method for three-dimensional track reconstruction of muon imaging according to claim 6, wherein the three-dimensional barycentric coordinates based on said electronic cloud are: ; Wherein, the The three-dimensional barycentric coordinates of the ith electronic cloud; The electric charge quantity of the jth signal point in the ith electronic cloud; The coordinates of the jth signal point in the ith electronic cloud; number of signal points in the i-th electron cloud.
8. The three-dimensional track reconstruction method for muon imaging according to claim 6, wherein the three-dimensional track reconstruction is completed by a screening reconstruction algorithm based on three-dimensional barycentric coordinates of a plurality of electronic clouds, and specifically comprises: Carrying out iterative random sampling and consensus set evaluation by using a random sample consistency algorithm, screening an inner point set conforming to a linear model from a three-dimensional gravity center point cloud, and deleting noise outliers in the inner point set; calculating the eigenvectors of the covariance matrix of the internal point set point cloud by using a principal component analysis algorithm; Determining a direction vector corresponding to the maximum characteristic value as a track trend; fitting the center of the track trend midpoint cloud mean value based on the track trend to obtain an optimal space linear equation; and determining an optimal space linear equation as a three-dimensional track reconstruction result.
9. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to perform the three-dimensional track reconstruction method of muon imaging as set forth in any of claims 1-8.
10. A computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor performs a three-dimensional track reconstruction method of muon imaging as set forth in any of claims 1-8.

Description

Three-dimensional track reconstruction method and equipment for muon imaging Technical Field The application relates to the field of signal detection and ray imaging, in particular to a three-dimensional track reconstruction method and equipment for muon imaging. Background The cosmic ray muon is naturally available, and has the advantages of extremely strong penetrating capacity, wide coverage range and the like. The muon imaging technology is used as an advanced nondestructive detection technology, has great application potential in various fields such as large-scale substance imaging (such as volcanic internal structure perspective and large-scale underground cavity detection), nuclear material and heavy metal detection (realizing non-invasive detection of closed containers such as containers and vehicles), archaeological research (such as pyramid internal closed chamber scanning) and the like, and has the core of imaging quality of reconstructing high-precision muon three-dimensional tracks. Currently, most muon track detection devices reconstruct muon three-dimensional tracks by building multi-layer detector arrays. The basic principle is that each layer of detector (which is usually composed of two groups of orthogonally arranged detection units) can measure two-dimensional coordinate points (X, Y) of muon passing through the layer, and a three-dimensional space straight line can be formed by fitting the coordinate points of multiple layers (at least upper and lower layers), so as to determine an incident track. However, the technical path has a significant limitation that the number of detection layers is often increased to achieve high spatial resolution, which results in a complex system structure and a large volume. In addition, the system has limited geometric acceptance, is influenced by the accumulation efficiency of the multi-layer detector, has limited number of effective muon events available for imaging, and directly influences imaging time and accuracy. The Time Projection Chamber (TPC) in combination with the microstructured gas readout plane (e.g., micromegas, GEM) provides a very promising alternative technology path. A time projection chamber is a gas detector capable of continuously recording a track of charged particles in three dimensions. The working principle of the device is that when muon passes through the sensitive volume of TPC, the muon interacts with working gas to ionize gas molecules to generate electron-ion pairs, electrons move to a reading plane at constant drift speed under the action of a uniform electric field, and the reading plane adopts a microstructure gas detector (such as Micromegas or GEM) with high spatial resolution, so that the arrival position and time information of electron cloud can be accurately measured. The working mechanism enables TPC to acquire three-dimensional continuous sampling information of the track through single detection under the condition of not depending on a multi-layer detection structure. However, the lack of a complete and efficient set of muon three-dimensional track reconstruction algorithms in existing track reconstruction systems presents challenges, especially for reconstruction of small angle-of-incidence muon cases. The traditional reconstruction algorithm has low efficiency in processing the electronic cloud, and most of the traditional reconstruction algorithm is used for respectively reconstructing two-dimensional plane tracks and then obtaining three-dimensional tracks, so that the associated information of the three-dimensional coordinates of the electronic cloud is not effectively utilized. In addition, the projection width of the small-angle incident muon track on the reading plane is obviously compressed, meanwhile, the longitudinal drift distance of the electron cloud is similar, so that the effective position information and the time information of the electron cloud are difficult to extract, track features on the two projection planes are weakened, and matching failure or false track generation is easily caused. Disclosure of Invention The application aims to provide a three-dimensional track reconstruction method and device for muon imaging, which can solve the problems of low reconstruction efficiency and fuzzy reconstruction of small-angle incident muon cases when a traditional reconstruction algorithm processes the muon track detected by TPC. In order to achieve the above object, the present application provides the following solutions: in a first aspect, the present application provides a three-dimensional track reconstruction method for muon imaging, comprising: acquiring an original waveform signal, wherein the original waveform signal is acquired through a muon imaging system, and the muon imaging system is a muon imaging system based on a time projection room detector; Preprocessing the original waveform signal to obtain a preprocessed original waveform signal; Carrying out channel waveform analysis on