A method for muon track reconstruction and imaging based on a muon detector

Abstract

This invention discloses a muon track reconstruction method and imaging method based on a muon detector, comprising the following steps: S1, determining the azimuth angles of the first, second, and third scintillators hit by the muon in any muon penetration event; S2, determining the x and y coordinates of the muon's incident and exit points based on the azimuth angle of the first scintillator; determining the z-axis coordinates of the muon's incident and exit points based on the azimuth angles of the second and third scintillators; S3, determining the muon's track based on the x, y, and z-axis coordinates of the incident and exit points. Compared with existing technologies, this invention significantly improves the accuracy of z-axis positioning while maintaining high detection efficiency, thereby improving the accuracy of muon track reconstruction and ore body imaging.

Description

Technical Field

[0001] This invention relates to the field of muon imaging technology, specifically to a method for reconstructing muon tracks and an imaging method based on a muon detector. Background Technology

[0002] Cosmic ray muons have a wide energy spectrum and strong penetrating power. Muon transmission imaging technology, which is based on muons, is a non-contact, long-distance imaging technology. It has the advantages of wide detection range, low detection cost, and green exploration in the exploration of deep mineral resources (about 600m from the ground).

[0003] Currently, muon imaging used in mineral resource exploration typically involves deploying a muon detection system in the borehole and using the difference in flux transmitted by cosmic ray muons to invert the density of underground ore bodies. The process is as follows:

[0004] (1) Drilling layout and installation of muon detection system

[0005] Based on prior information such as geological and geophysical exploration data, wells are deployed above the predicted area of ​​the target ore body, such as... Figure 1 As shown;

[0006] A muon detector is lowered along the wellbore axis inside the well. The muon detector typically consists of a scintillator (model: EJ-200) and matching electronics, and is connected to the ground data acquisition device via a transmission cable.

[0007] (2) Muzi Event Collection and Muzi Track Reconstruction

[0008] High-energy muons from cosmic rays are naturally incident from the Earth's surface into the ground (orange dashed line in the figure). Some muons pass through the overlying rock strata, ore body and surrounding rock before reaching the muon detector in the well.

[0009] The muon detector in the well generates a scintillation signal by the deposited energy produced when muons pass through a scintillator. This signal is transmitted to a ground data acquisition system via a transmission cable to record raw data such as the corresponding scintillator number, trigger time, and signal amplitude for each event.

[0010] The zenith and azimuth angles of the muon can be reconstructed based on the scintillator number, and the point of impact on the detector can be derived from this, thus constructing the muon track and obtaining the muon flux.

[0011] (3) Ore body density inversion and imaging based on muon flux

[0012] The muon transmittance along each path was calculated by comparing it with the muon flux under conditions of no ore body or homogeneous rock mass.

[0013] A voxel model covering the well was established, and the penetration length of each muon path in the model was linked to the corresponding transmittance, thus constructing a physical relationship of "path integral density - transmittance".

[0014] Algebraic reconstruction inversion is used to jointly solve the muon path and invert the average density of each voxel or the density difference with the surrounding rock.

[0015] Based on the obtained density distribution, areas with significant density differences from the surrounding rock mass were identified and interpreted as potential mineral resource occurrence spaces.

[0016] Currently, drilling-type muon detectors used for deep mineral resource exploration employ a cylindrical structure with orthogonal coupling of arc-shaped scintillator strips and wedge-shaped long strip scintillators. The purpose is to maximize muon detection efficiency within the narrow space of a borehole and to achieve three-dimensional reconstruction of the muon incident position for imaging of ore bodies / anomalies outside the well.

[0017] The aforementioned drilling-type muon detector can detect the approximate location of underground ore bodies under drilling conditions, but it still has the following shortcomings in practical applications, mainly due to the limitations of existing detector structures and location reconstruction methods:

[0018] (1) Design and arrangement of scintillators

[0019] Currently, drilling-type muon detectors used in deep-earth mineral resource exploration employ an orthogonal coupling method of arc-shaped scintillator strips and wedge-shaped strip scintillators to acquire the energy deposition of each scintillator. The circumferential angle is subdivided using multiple wedge-shaped pixels, while the axial direction is achieved by stacking longer arc-shaped strips in layers to increase the effective thickness and detection area. This design significantly improves detection efficiency and statistical output with a fixed borehole diameter, but it also results in a large solid angle range corresponding to each strip scintillator. A single channel receives muons from a wide zenith angle range simultaneously. During muon track reconstruction, the incident direction inferred from the hit scintillator and limited layering information is a large fan-shaped area, thus reducing zenith angle resolution.

[0020] (2) Muon tracks reconstructed by the charge centroid method

[0021] In the existing structure, the muon traverses the arc-shaped scintillator along the well axis. Coordinates are typically estimated by weighting the energy of each deposition layer. However, in reality, due to random effects such as energy fluctuations and multiple scattering within the scintillator, muons at different zenith angles and along different paths can easily produce similar energy distribution patterns, even within the same group. It may correspond to multiple different realities. Tracks, therefore for The reconstructed coordinates tend to represent the average sedimentary center rather than a precise geometric location, leading to... Coordinate estimation suffers from significant systematic errors and statistical fluctuations.

[0022] In summary, existing drilling-type muon detection systems, in their structural design, prioritize increasing the effective detection area at the expense of muon zenith angle resolution, further hampered by the use of the charge centroid method for reconstruction. The large axial coordinate error ultimately resulted in low accuracy in the reconstruction of the muzi track and the imaging of the ore body. Summary of the Invention

[0023] This invention provides a muon track reconstruction method and imaging method based on a muon detector to solve the technical problem of low accuracy in existing muon track reconstruction and ore body imaging technologies.

[0024] To achieve the above objectives, the present invention adopts the following technical solution.

[0025] On the one hand, a muon track reconstruction method based on a muon detector is provided and applied to a muon detector;

[0026] The muon detector comprises: a first scintillator layer, a second scintillator layer, and a third scintillator layer; the first scintillator layer is formed by multiple vertically arranged elongated first scintillators forming a cylindrical shape; the second scintillator layer comprises multiple elongated second scintillators spirally and tightly wound around the inner wall of the first scintillator layer; and the third scintillator layer comprises multiple elongated third scintillators spirally and tightly wound around the outer wall of the first scintillator layer, wherein the winding directions of the second and third scintillators are opposite.

[0027] The method includes the following steps:

[0028] S1. Based on the numbers of the first, second, and third scintillators hit by the muon in any muon penetration event, determine the azimuth angles of the first, second, and third scintillators hit by the muon.

[0029] S2. Determine the incident and exit points of the muon based on the azimuth angle of the first scintillator hit by the muon. Axis coordinate values;

[0030] The incident and exit points of the muon are determined based on the azimuth angles of the second and third scintillators hit by the muon. Axis coordinate values;

[0031] S3. Based on the incident and exit points of the muon The axis coordinates determine the path of the muon;

[0032] Among them, the scintillators hit by the muon include scintillators that are incident on the muon and scintillators that are ejected from the muon.

[0033] Therefore, this invention introduces an inner and outer double-helix coupling structure into a drilling-type muon detector, thereby... The coordinates are transformed into a spiral phase difference, making Z-axis localization no longer relies on the axial segmentation of the scintillator, but is determined by the linear response of the phase difference. Based on this, a double-helix coupled localization algorithm is further proposed. Through the synergistic effect of the double-helix structure and this algorithm, the accuracy of z-axis localization is significantly improved while maintaining high detection efficiency, thereby enhancing the accuracy of muon track reconstruction and ore body imaging. It should be noted that when a muon incident and emitted simultaneously strike the detector's scintillator (in which case there are three incident and three emission points respectively), it can be considered a muon breakdown event.

[0034] In some embodiments, in step S1, the azimuth angles of the first, second, and third scintillators hit by the muon are determined according to the following formula:

[0035] ;

[0036] ;

[0037] ;

[0038] In the formula, , , These are the azimuth angles of the first, second, and third scintillators hit by the muon, respectively. , , These represent the azimuth increments of each scintillator in the first, second, and third scintillator layers as a function of the circumference. , , These are the numbers of the first, second, and third scintillators that were hit by the muon.

[0039] In some embodiments, in step S2, the incident point and exit point of the muon are determined according to the following formula. Axis coordinate values:

[0040] ;

[0041] ;

[0042] The incident and exit points of the muon are determined using the following formula. Axis coordinate values:

[0043] ;

[0044] In the formula, The helix angle of the scintillator; , The radii of the first scintillator layer, the second scintillator layer, and the third scintillator layer, respectively; , These are the azimuth angles of the first, second, and third scintillators that were hit by the muon.

[0045] To avoid azimuth angle jump errors, in some embodiments, steps S1 and S2 further include: normalizing the azimuth angle to normalize its value to a specified value. Within the range. Because the helical plastic glider spans multiple circumferential cycles along the axial direction, the azimuth angle will... The periodicity of the numbering can lead to ambiguity in the multiple loops, causing a shift in the solution when finding the intersection point of the inner and outer layers of lines. To address this, this invention performs a normalization (wrap) process on the azimuth angles obtained from the numbering, mapping the angles to a fixed interval. This step is also known as angle wrapping or principal value representation in signal processing and interferometry. The aforementioned normalization method is existing technology.

[0046] In some embodiments, the process between steps S2 and S3 further includes: The axis coordinate values ​​are corrected to eliminate axial deviations introduced by multiple revolutions. Periodic ambiguities are addressed. The axial coordinate values ​​are corrected to eliminate axial deviations introduced by multiple ring numbers, while also ensuring the uniqueness of the azimuth angle.

[0047] On the other hand, an imaging method based on a muon detector is provided, comprising the following steps:

[0048] The muon flux is obtained from the tracks of multiple muons;

[0049] The muon transmittance on each track was calculated by comparing it with the muon flux under conditions of no ore body or homogeneous rock mass.

[0050] A voxel model covering the well was established, and the penetration length of each muon track in the model was correlated with the corresponding transmittance, thus constructing the physical relationship between path integral density and transmittance.

[0051] Algebraic reconstruction and inversion were used to jointly solve for the Muzi track and obtain the density distribution of the rock mass.

[0052] Based on the density distribution of the rock mass, areas with significant density differences from the surrounding rock mass are identified, and these areas are determined to be mineral resource occurrence spaces.

[0053] The muon tracks are obtained using the muon track reconstruction method based on the muon detector described above.

[0054] In another aspect, a computer device is provided, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above-described method.

[0055] In another aspect, a computer-readable storage medium is provided that stores a computer program or instructions thereon, which, when executed by a processor, implement the steps of the above-described method.

[0056] In another aspect, a computer program product is provided, including a computer program or instructions that, when executed by a processor, implement the steps of the above-described method.

[0057] This invention has at least the following technical effects or advantages: Existing drilling-type muon detectors, due to... Axial positioning is treated as a problem of strip-length projection or axial segmentation, inevitably sacrificing zenith angle and axial resolution when increasing the detection area. This invention addresses this by introducing an inner and outer double-helix coupling structure into a drilling-type muon detector. The coordinates are transformed into a spiral phase difference, making The z-axis positioning no longer relies on the axial segmentation of the scintillator, but is determined by the linear response of the phase difference. Based on this, a double-helix coupling positioning algorithm is further proposed. Through the synergistic effect of the double-helix structure and this algorithm, the accuracy of z-axis positioning is significantly improved while maintaining high detection efficiency, thereby enhancing the accuracy of muon track reconstruction and ore body imaging. Furthermore, this invention also solves practical engineering problems such as axial deviation and azimuth jump errors caused by the introduction of the inner and outer double-helix coupling structure; the error between the reconstructed result and the actual result does not exceed 5 mm. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of existing mineral exploration using muon detection systems;

[0059] Figure 2 This is a three-dimensional structural diagram of the scintillator arrangement in the muon detector of the present invention;

[0060] Figure 3 This is a schematic diagram (top view) of the muon detector's state during a single muon breakdown event in this invention.

[0061] Figure 4 This is a schematic diagram (stereoscopic view) of the state of the muon detector during a single muon breakdown event in this invention.

[0062] Figure 5 For the muon detector in this invention Schematic diagram in coordinate system;

[0063] Figure 6 This is a schematic diagram showing the azimuth angles corresponding to different numbered scintillators in this invention;

[0064] Figure 7 For the second scintillator layer in this invention Schematic diagram in coordinate system;

[0065] Figure 8 The third scintillator layer in this invention Schematic diagram in coordinate system;

[0066] Figure 9 For the second and third scintillator layers in this invention A schematic diagram of overlapping coordinates;

[0067] Figure 10 This is the muon opacity imaging result obtained through software simulation in this invention;

[0068] Figure 11 This is the muon opacity imaging result obtained by reconstructing muon tracks in this invention;

[0069] Figure 12 This invention uses simulation software to obtain the muon flux diagram under the condition of no ore vein.

[0070] Figure 13 This invention presents a muon flux diagram obtained through simulation software under ore vein conditions. Detailed Implementation

[0071] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0072] Example 1

[0073] A muon track reconstruction method based on muon detectors, applied to, for example Figure 2 and Figure 3The muon detector shown comprises a first scintillator layer 11, a second scintillator layer 12, and a third scintillator layer 13. The first scintillator layer consists of multiple vertically arranged elongated scintillators forming a cylindrical shape. The second scintillator layer comprises multiple elongated scintillators spirally and tightly wound around the inner wall of the first scintillator layer. The third scintillator layer comprises multiple elongated scintillators spirally and tightly wound around the outer wall of the first scintillator layer. The winding directions of the elongated scintillators in the second and third scintillator layers are opposite. "Tightly wound" means there are no gaps between adjacent elongated scintillators to maximize muon capture. For ease of fabrication, a hollow aluminum cylinder 2 is placed at the center of the muon detector, and the first, second, and third scintillator layers 11, 12, and 13 are located on the outer surface of the hollow aluminum cylinder 2. In this embodiment, for ease of distinction, the elongated scintillators in the first scintillator layer 11 are red, the elongated scintillators in the second scintillator layer 12 are blue, and the elongated scintillators in the third scintillator layer 13 are green. All elongated scintillators are scintillators with a cross-sectional dimension of [missing information]. The length of the elongated scintillators in the first scintillator layer 11 is 500 mm. The elongated scintillators in the second scintillator layer 12 and the third scintillator layer 13 are arranged at a helix angle. 21° spiral winding, with a length of 535mm.

[0074] The Muzi track reconstruction method includes the following steps:

[0075] S1. Based on the numbers of the first, second, and third scintillators hit by the muon in any muon penetration event, determine the azimuth angles of the first, second, and third scintillators hit by the muon.

[0076] S2. Determine the incident and exit points of the muon based on the azimuth angle of the first scintillator hit by the muon. Axis coordinate values;

[0077] The incident and exit points of the muon are determined based on the azimuth angles of the second and third scintillators hit by the muon. Axis coordinate values;

[0078] S3. Based on the incident and exit points of the muon The axis coordinates determine the path of the muon;

[0079] Among them, the scintillators hit by the muon include scintillators that are incident on the muon and scintillators that are ejected from the muon.

[0080] Specifically, by utilizing the natural incidence of cosmic ray muons, energy is deposited on the struck scintillator. The SiPM coupled to the scintillator generates amplitude information to identify the scintillator element first struck by the muon; the scintillator with the highest signal amplitude is identified as having been struck by a muon. When the incident and emitted muons simultaneously pass through the three layers of scintillators, the signals triggered by multiple channels are clustered according to a time window. Multiple scintillators belonging to the same muon strike are grouped into one event, obtaining the raw data for each event. When a muon incident and emitted simultaneously strike the detector's scintillator (at which point there are three incident and three emission points), it can be considered a valid event, such as... Figure 3 and Figure 4 As shown. Figure 3 and Figure 4 In the diagram, the yellow lines represent the muon tracks, and the red dots represent the incident and exit points.

[0081] It should be noted that the incident and exit points of a muon can be distinguished by the order of signal arrival times; that is, the signal arrival time at the incident point precedes the signal arrival time at the exit point. Furthermore, in the scintillator readout muon track detection system, the same muon hit event is constructed using a coincidence time window + multiple triggering mechanism, employing a "threshold trigger + coincidence determination" event construction method for muon detection DAQ. First, the front-end electronics process the SiPM signal of each detection channel. When the signal exceeds a preset threshold, a hit occurs in that channel. Simultaneously, the readout circuit samples and stores the signal and time information of the hit, then digitizes it. Subsequently, the motherboard aggregates data from multiple data acquisition boards and performs coincidence processing on the motherboard side. If multiple hit information from different detection channels satisfies consistency under a preset coincidence logic (i.e., the coincidence condition is met), these signals are determined to be the same event caused by the same particle passage; otherwise, they are not merged into the same event.

[0082] In step S1, in order to ensure that the number of each scintillator can be accurately mapped to the corresponding azimuth angle... This invention constructs a coordinate system based on a double-helix muon detector. Coordinates. First, establish coordinates on any cross-section of the detector. Coordinate system as Figure 6 As shown, the preferred cross-section is the middle section of the detector.

[0083] like Figure 5 As shown, from Initially, each scintillator proceeds sequentially in either clockwise or counterclockwise direction according to its corresponding azimuth angle. Numbering starts from 0. This refers to the numbering of the scintillators. For a three-layered scintillator arrangement, since they are evenly spaced along the circumference on the reference section, and the number of the inner three layers of scintillators is... , , Establish the relationship shown in the following formula:

[0084] ;

[0085] ;

[0086] ;

[0087] in , These are the radii of the first scintillator layer, the second scintillator layer, and the third scintillator layer, respectively. Let be the width of the scintillator. Therefore, the relationship between the scintillator and the azimuth angle satisfies the following:

[0088] ;

[0089] ;

[0090] ;

[0091] in, , , These are the azimuth increments of each scintillator in the first, second, and third scintillator layers as the circumference changes.

[0092] At this point, the scintillator's number can be accurately mapped to its corresponding azimuth angle. Simply multiply the corresponding angle increment by the corresponding number. That's all, that's all , , ,in , , These are the numbers of the first, second, and third scintillators that were hit (including both entry and exit) by the muon in a specific muon penetration event. It should be noted that the azimuth angle in this invention... This refers to a scintillator in In coordinate system The value of the coordinates, Figure 7 The diagram shows the azimuth angles corresponding to scintillators numbered 0-3 in a certain scintillator layer. .

[0093] In step S2, to ensure that the azimuth angle corresponding to the number of each scintillator is... Able to map precisely to The coordinate values ​​of the axes can be calculated using the following formula:

[0094] ;

[0095] ;

[0096] ;

[0097] In the formula, The helix angle of the scintillator; , , The radii of the first scintillator layer, the second scintillator layer, and the third scintillator layer, respectively; , , These are the azimuth angles of the first, second, and third scintillators hit by the muon, respectively. Based on the above formula, the coordinates of the muon's incident point can be calculated. and the coordinates of the launch point .

[0098] The derivation of the above formula is as follows: Expanding along the circumference of the detector, establish the scintillators in the second scintillator layer (blue layer) and the third scintillator layer (green layer). Coordinate system as Figure 8 As shown. The detector travels along... The axis unfolds into Plane after creation coordinate system and The relationship between the coordinate systems is as follows: , , , ;use Represents a layer of blue, red, or green. ; The strip represents the number of a certain scintillator layer. On the unfolded plane, the centerline of the plastic glider satisfies: ;

[0099] in It was Mu Zi who was there. The step size of the l-axis in the coordinate system. for The step size of the axis.

[0100] The spiral scintillators of the green (g) outer layer and the blue (b) inner layer are approximately two straight lines on the unfolded plane (the width and thickness of the scintillators are ignored in this calculation, and the calculation is derived based on the centerline of the scintillators). The slope of the straight lines is: ;

[0101] Therefore, the system of equations for the straight lines can be obtained as follows:

[0102] - (1)

[0103] - (2)

[0104] In the formula, , These represent the green scintillator determined by... The z-coordinate is determined by the coordinates and the blue scintillator. , These represent the green and blue scintillators respectively. Parameterized arc length in a coordinate system The spiral angle of the green and blue scintillators.

[0105] For the same impact event at the same end (incident or exit), the inner and outer layer impacts originate from the same muon track; therefore, the axial positions determined by the two layers must be consistent (e.g., Figure 9 As shown), the intersection points satisfy: The intersection point can be solved using the above conditions, thus obtaining the z-coordinate of the hit point. The specific steps are as follows:

[0106] By combining equations (1) and (2), we can obtain:

[0107] ;

[0108] when When, cancel out both sides of the above equation. have to:

[0109] - - ;

[0110] because , , , ;

[0111] Substituting into the above formula, we get:

[0112] - - ;

[0113] ;

[0114] Solving for:

[0115] ;

[0116] Will Substituting into equation (1), we get:

[0117] ;

[0118] Therefore, we can conclude that:

[0119] The radius of the red scintillator in the middle layer is known to be... This allows us to determine the point of impact. Axis coordinates and The axis coordinates are as follows:

[0120] ;

[0121] ;

[0122] In step S3, after obtaining the muon incident point... coordinates and launch point coordinates Subsequently, since the muon moves approximately in a straight line within the effective length of the detector, its trajectory direction vector in the detector coordinate system... That is, by and The connection is determined, thus yielding the following formula:

[0123] ;

[0124] At this point, the reconstruction of the Mun track in a Mun penetration event can be completed.

[0125] As a preferred option, in order to avoid deviations in numerical calculations of the data, and also to ensure the azimuth angle To ensure uniqueness, steps S1 and S2 further include: normalizing the azimuth angle to normalize its value to a specified value. Within the interval. This embodiment introduces the wrap function to wrap the azimuth angle. Values ​​normalized to Within the interval, the normalization formula is as follows:

[0126] ;

[0127] The above normalization formula applies to the first, second, and third scintillators and is used to determine the plastic scintillator strip number. In this case, calculate the azimuth angle corresponding to the flashing bar. normalized value In the formula, The azimuth angle is set to zero offset, which can be manually calibrated during installation; , indicating that the scintillator number follows The direction of increment (+1 indicates that the number increases, -1 indicates that the number decreases); express When it increases, the intersection point is at The space can move clockwise or counterclockwise (+1 indicates counterclockwise, -1 indicates clockwise). Indicates the circumferential angle step size; Represents the first scintillator layer Root scintillator, , , ,for example The first layer representing the blue scintillator Root scintillator. The total number of scintillator numbers in a certain layer, for example This indicates the total number of blue flashing elements.

[0128] In numerical calculations, if angles are not normalized, the same physical direction (which exists) may be misused as an angle with abrupt changes in range, leading to "jump errors" in the residuals and fitting. For example, the azimuth angles R of the incident or exit points of a muon might be 10° and 350°, which are geometrically only 20° different. However, without the wrap function, these angles could be amplified to a magnitude of 340° in numerical calculations. Therefore, to avoid such abrupt changes, this function is defined to ensure that the output always falls within (…). )between.

[0129] As a preferred embodiment, steps S2 and S3 further include: ... The axis coordinate values ​​are corrected to eliminate axial deviations introduced by multiple ring numbering.

[0130] Since the detector uses a three-layer spiral scintillator for coupling and positioning, the true azimuth angle is:

[0131] = +2 ;

[0132] The integer term represents the number of mapping revolutions, i.e. how many whole revolutions the reconstructed azimuth angle deviates from the true azimuth angle; This is the actual azimuth angle; The azimuth angle calculated using the above method is the reconstructed azimuth angle.

[0133] ;

[0134] in = - This indicates the offset; if the correct offset is not selected... and ,but = - Will because caused by the jump The offset.

[0135] The derivation yields:

[0136]

[0137]

[0138] ;

[0139] In the formula ( - The term ) is the axial offset correction term introduced by the muon due to the ambiguity in the numbering of multiple turns of the spiral. When using the above formula for reconstruction in simulation or field measurement, an appropriate integer should be selected. and .

[0140] Due to pitch Indicates the intersection point is Offset on the axis is equivalent to on The spatial step size, therefore, for a cylindrical detector, the helix angle is... Under the given conditions, we have: Therefore, this pitch can be used to give... The upper bound, that is, for an event on a certain layer, the maximum number of complete loops that it can traverse from the top to the bottom of the detector is no more than: ;

[0141] in The altitude is the height of the detector.

[0142] so The method of selection is as follows:

[0143] ;

[0144] in The value is typically set to 1 to cover boundary events and small deviations caused by plastic flash thickness.

[0145] So put Substitute We can obtain:

[0146] ;

[0147] Then, through and At the upper limit Enumerate positive integers, and compare them with the true azimuth angle of the muon. Perform calibration comparisons and select the one with the smallest error. and The value is taken as the preferred value.

[0148] The corresponding deviation for the entire lap at this point is:

[0149] = ( - );

[0150] Therefore, the calculated whole-circle deviation can be used to... Coordinate value correction: .in Before and after correction, respectively. Coordinate values.

[0151] right The following is an example of how to calculate the axis coordinate values ​​for correction:

[0152] effective height of the detector The overall diameter of the detector is The radius of the green layer centerline is approximately 75.1 mm; the helix angle is... ; =48, =35; therefore 472mm, cot21°=2.605.

[0153] according to have to 1230;

[0154] Therefore:

[0155] 0.41;

[0156] ;

[0157] so and The range of enumeration is: , ;

[0158] Take the following two EventID records as an example:

[0159] EventID:913

[0160] Energy Deposition (GeV):

[0161] GreenLayer: 0.00428374 GeV

[0162] RedLayer:0.0019166GeV

[0163] BlueLayer:0.000968663GeV

[0164] In:Layer=0,Strip=59,Copy=4844,Edep=4.28374MeV

[0165] In:Layer=1,Strip=66,Copy=3337,Edep=1.9166MeV

[0166] In:Layer=2,Strip=8,Copy=5424,Edep=0.968663MeV

[0167] Out:Layer=2,Strip=8,Copy=5424,Edep=0.964582MeV

[0168] Out:Layer=1,Strip=67,Copy=3386,Edep=1.13087MeV

[0169] Out:Layer=0,Strip=60,Copy=4863,Edep=4.28374MeV

[0170] EventID:1205

[0171] EnergyDeposition(GeV):

[0172] GreenLayer:0.000647961GeV

[0173] RedLayer:0.00299932GeV

[0174] BlueLayer:0.00338716GeV

[0175] In:Layer=0,Strip=39,Copy=4443,Edep=0.647961MeV

[0176] In:Layer=1,Strip=47,Copy=2384,Edep=2.99932MeV

[0177] In:Layer=2,Strip=56,Copy=6384,Edep=3.38716MeV

[0178] Out:Layer=2,Strip=56,Copy=6383,Edep=3.38397MeV

[0179] Out:Layer=1,Strip=47,Copy=2383,Edep=0.712755MeV

[0180] Out:Layer=0,Strip=39,Copy=4443,Edep=0.647604MeV

[0181] In this context, EventID represents the sequence number of the hit event, EnergyDeposition represents the deposited energy, GreenLayer represents the green layer, RedLayer represents the red layer, BlueLayer represents the blue layer, In represents the incident signal, Out represents the emitted signal, layer represents the hit sequence, 0 represents the green layer, 1 represents the red layer, and 2 represents the blue layer. Strip represents the manually defined plastic scintillator number, copy represents the model volume number in the Geant4 simulation software, and Edep represents the deposited energy.

[0182] Indexing via strip: ;

[0183] This is a section of Python code about indexing by strip number, indicating how to use the strip number to determine which strip in the Geant4 simulation software was hit by a muon and which model volume number copy was affected. This indicates a modulo operation, preventing negative numbers from occurring during simulation due to multi-threaded data recording. .

[0184] Next by

[0185] ;

[0186] ;

[0187] Solve for the In / Out of the green layer: =49.22° / 34.21°;

[0188] In / Out of the blue layer: =-65.74° / -47.23°.

[0189] Due to axial error = - ;

[0190] in =105.1mm, =127.1mm;

[0191] Therefore, by , , available:

[0192] In: =0.06498, =34.335;

[0193] Out: =0.06531, =-17.045;

[0194] Therefore, in the example above, the In terminal (greenstrip=59, bluestrip=8) of EventID:913 records a true Z-coordinate of 123.84 mm in the simulation.

[0195] Green layer step size angle: =360 / 80=4.5;

[0196]

[0197] Blue layer step size angle: =360 / 66=5.45;

[0198]

[0199] Subsequently passed and Enumerate ∈{-2,-1,0,1,2}:

[0200] , .

[0201] Table 1 enumerates the specific data in Example 1:

[0202]

[0203] Finally obtained ( , )=(-2,2), =124.05mm.

[0204] Similarly, the Out terminal of EventID: 913 (greenstrip=60, bluestrip=8) records a true Z-coordinate of 98.08 mm in the simulation.

[0205] ;

[0206] ;

[0207] enumerate: , .

[0208] Table 2 enumerates the specific data for Example 2:

[0209]

[0210] get( , )=(-2,2), =94.92mm.

[0211] The In end can be obtained by stripping, and the actual Z coordinate recorded in the simulation is 103.15 mm.

[0212] ;

[0213] ;

[0214] enumerate: , .

[0215] Table 3 enumerates the specific data for Example 3:

[0216]

[0217] Finally obtained ( , )=(-2,1), =100.37mm.

[0218] The Out end can be obtained by stripping, and the actual Z coordinate recorded in the simulation is 94.91 mm.

[0219] ;

[0220] ;

[0221] enumerate: , .

[0222] Table 4 enumerates the specific data for Example 4:

[0223]

[0224] Finally obtained ( , )=(-2,1), =96.85mm.

[0225] Example 2

[0226] An imaging method based on a muon detector includes the following steps:

[0227] The muon flux is obtained from the tracks of multiple muons;

[0228] The muon transmittance on each track was calculated by comparing it with the muon flux under conditions of no ore body or homogeneous rock mass.

[0229] A voxel model covering the well was established, and the penetration length of each muon track in the model was correlated with the corresponding transmittance, thus constructing the physical relationship between path integral density and transmittance.

[0230] Algebraic reconstruction and inversion were used to jointly solve for the Muzi track and obtain the density distribution of the rock mass.

[0231] Based on the density distribution of the rock mass, areas with significant density differences from the surrounding rock mass are identified, and these areas are determined to be mineral resource occurrence spaces.

[0232] The muon tracks are obtained using the muon track reconstruction method based on the muon detector described above.

[0233] Detailed experimental procedure:

[0234] I. Model Building and Parameter Setting

[0235] (1) Based on the application scenario (wellbore constraints, downhole length constraints, etc.), determine the structure and geometric parameters of the detector, including: detector height H, detector radius R, width W and thickness T of the scintillator strip, and the helix angle θ of the inner blue layer and the outer green layer scintillator. The helix angle is used to define the drift relationship of the plastic scintillator strip in the circumferential coordinates as it advances axially, thus providing a basis for subsequent z- Joint reconstruction provides the geometric basis; the width W and the number of plastic scintillator lines N within the layer affect the corresponding azimuth step size Δ. This affects the accuracy of the azimuth angle and the detection efficiency;

[0236] (2) Establish a three-dimensional simulation model corresponding to mineral resource exploration. The model consists of a mountain, vertical logging, and the ore body surrounding the well. Specifically, this includes: setting the overall size and material parameters of the mountain (such as density and main components to characterize the background surrounding rock); setting up a vertical drilling structure inside the mountain and adjusting the drilling depth range according to the ore body's location in space, so that the detector can form an effective muon penetration path between the detector and the ore body area at a preset depth; and setting up the three-dimensional geometry of the ore body around the well, assigning the ore body a corresponding density or equivalent attenuation coefficient to reflect the density difference between the ore body and the surrounding rock of the mountain. Subsequently, a double-helix muon detector is deployed in a designated depth range within the well to form a detection scene for muon transmission statistics and track reconstruction.

[0237] II. Data Collection

[0238] (1) Set the conditions that meet the output recording muon (the incident and the exit simultaneously hit the three layers of scintillators), and record the number (strip) of the scintillator it hits and the energy deposition (E / MeV);

[0239] (2) Clustering data for the same event, such as using EventID numbers to record data under that event; relevant data collection examples are as follows:

[0240] EventID:197

[0241] Energy Deposition (GeV):

[0242] GreenLayer: 0.00454287 GeV

[0243] RedLayer: 0.0032383 GeV

[0244] BlueLayer: 0.00290852 GeV

[0245] In:Layer=0,Strip=35,Copy=1540,Edep=4.54287MeV

[0246] In:Layer=1,Strip=39,Copy=1111,Edep=3.2383MeV

[0247] In:Layer=2,Strip=5,Copy=1694,Edep=2.90852MeV

[0248] Out:Layer=2,Strip=5,Copy=1694,Edep=2.90685MeV

[0249] Out:Layer=1,Strip=39,Copy=1110 f Edep=0.922443MeV

[0250] Out:Layer=0,Strip=37,Copy=1561,Edep=3.06552MeV

[0251] EventID:334

[0252] EnergyDeposition(GeV):

[0253] GreenLayer:0.0020502GeV

[0254] RedLayer:0.0024242GeV

[0255] BlueLayer:0.00449805GeV

[0256] In:Layer=0,Strip=38,Copy=1573,Edep=2.0502MeV

[0257] In:Layer=1,Strip=1,Copy=47,Edep=2.4242MeV

[0258] In:Layer=2,Strip=10,Copy=1750,Edep=4.49805MeV

[0259] Out:Layer=2,Strip=8,Copy=1727,Edep=4.47512MeV

[0260] Out:Layer=1,Strip=1,Copy=47,Edep=2.42417MeV

[0261] Out:Layer=0,Strip=38,Copy=1573,Edep=2.04945MeV

[0262] EventID:454

[0263] EnergyDeposition(GeV):

[0264] GreenLayer:0.00208056GeV

[0265] RedLayer:0.00186247GeV

[0266] BlueLayer:0.00413702GeV

[0267] In:Layer=0,Strip=17,Copy=1336,Edep=2.08056MeV

[0268] In:Layer=1,Strip=37,Copy=1045,Edep=1.86247MeV

[0269] In:Layer=2,Strip=36,Copy=2031,Edep=4.13702MeV

[0270] Out:Layer=2,Strip=17,Copy=1821,Edep=4.13693MeV

[0271] Out:Layer=1,Strip=37,Copy=1045,Edep=1.86176MeV

[0272] Out:Layer=0,Strip=17,Copy=1336,Edep=2.07812MeV

[0273] EventID:553

[0274] EnergyDeposition(GeV):

[0275] GreenLayer:0.0111374GeV

[0276] RedLayer:0.00985444GeV

[0277] BlueLayer:0.00833747GeV

[0278] In:Layer=0,Strip=5,Copy=1210,Edep=11.1374MeV

[0279] In:Layer=1,Strip=11,Copy=330,Edep=9.85444MeV

[0280] In:Layer=2,Strip=19,Copy=1851,Edep=8.33747MeV

[0281] Out:Layer=2,Strip=18,Copy=1839,Edep=8.33249MeV

[0282] Out:Layer=1,Strip=11,Copy=327,Edep=0.474757MeV

[0283] Out:Layer=0,Strip=6,Copy=1220,Edep=5.10331MeV

[0284] The data of the electronic signal output triggered by the scintillator is used to distinguish each event and identify it using EventID. The layer indicates the order of the hits: 0 indicates the hit of the outer green layer, 1 indicates the hit of the middle red layer, and 2 indicates the hit of the inner blue layer. The copy number indicates the corresponding strip number defined by the user in Geant4.

[0285] III. Muzi Coordinates and Track Reconstruction

[0286] The reconstructed muon tracks were obtained using the muon track reconstruction method based on muon detectors described in Example 1. .

[0287] IV. Image Reconstruction

[0288] Based on Beer-Lambert's law, the transmittance T under two conditions—with and without ore bodies—is expressed as follows:

[0289] ;

[0290] ;

[0291] in, Indicates incident intensity, Indicates the intensity after passing through depth L. This represents the linear attenuation coefficient related to energy. This indicates the effective count of muons when there is a mineral vein. The effective count of muons when there are no mineral veins can be represented by the Beer-Lambert law, which allows us to derive the relevant opacity. As shown in the following formula:

[0292] ;

[0293] This allows for the analysis of flux differences and density anomalies caused by the presence of ore bodies through opacity analysis, enabling the transmission imaging of the detected ore veins using a double-helix muon detector. Figure 10 and 11 The results show the muon opacity imaging obtained by the simulation software Geant4 and the muon opacity imaging obtained by the muon tracks reconstructed by this invention. The comparison shows that the two are basically consistent.

[0294] Figure 12 and 13 Mun flux maps are shown for both the vein-free and vein-containing conditions. Reconstructed mun imaging results demonstrate... Figure 13 In the region between approximately 225° and 280°, and with a zenith angle between approximately 5° and 45°, a high-density area exists, resulting in lower muon flux compared to other regions. Figure 10 and Figure 11 The results of the opacity imaging are consistent with those in the image, so it can be inferred that there is a gold deposit with a density difference from the surrounding mountains and surrounding rocks at a location of approximately 225°–280° and a zenith angle of approximately 5°–45°.

[0295] Example 3

[0296] A computer device includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described above.

[0297] Example 4

[0298] A computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the above-described method.

[0299] Example 5

[0300] A computer program product includes a computer program or instructions that, when executed by a processor, implement the steps of the above-described method.

[0301] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0302] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention and form different embodiments.

[0303] Furthermore, some of the embodiments described herein are methods or combinations of method elements that can be implemented by a processor of a computer system or by other means of performing the functions. Therefore, a processor having the necessary instructions for implementing the methods or method elements forms means for implementing the methods or method elements. Furthermore, the elements described herein in the apparatus embodiments are examples of means for implementing the functions performed by elements for the purposes of carrying out the invention.

[0304] The various techniques described herein can be implemented in combination with hardware or software, or a combination thereof. Thus, the methods and apparatus of the present invention, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embedded in a tangible medium, such as a floppy disk, CD-ROM, hard disk, or any other machine-readable storage medium, wherein when the program is loaded into and executed by a machine such as a computer, the machine becomes an apparatus for practicing the present invention.

[0305] When the program code is executed on a programmable computer, the computing device generally includes a processor, a processor-readable storage medium (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. The memory is configured to store program code; the processor is configured to execute the method of the present invention according to instructions in the program code stored in the memory.

[0306] By way of example, and not limitation, computer-readable media include computer storage media and communication media. Computer storage media stores information such as computer-readable instructions, data structures, program modules, or other data. Communication media generally embodies computer-readable instructions, data structures, program modules, or other data in the form of modulated data signals such as carrier waves or other transmission mechanisms, and includes any information delivery medium. Any combination of the above is also included within the scope of computer-readable media.

[0307] As used herein, unless otherwise specified, the use of ordinal numbers such as “first,” “second,” “third,” etc., to describe ordinary objects merely indicates different instances of similar objects and is not intended to imply that the objects being described must have a given order in time, space, ordering, or any other manner.

[0308] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

[0309] Finally, it should be noted that this invention does not explain in detail the common knowledge recognized by those skilled in the art. The above description is only a specific embodiment of this invention and is not intended to limit this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A method for reconstructing muon tracks based on a muon detector, characterized in that, Applied to muon detectors; The muon detector comprises: a first scintillator layer, a second scintillator layer, and a third scintillator layer; the first scintillator layer is formed by multiple vertically arranged elongated first scintillators forming a cylindrical shape; the second scintillator layer comprises multiple elongated second scintillators spirally and tightly wound around the inner wall of the first scintillator layer; and the third scintillator layer comprises multiple elongated third scintillators spirally and tightly wound around the outer wall of the first scintillator layer, wherein the winding directions of the second and third scintillators are opposite. The method includes the following steps: S1. Based on the numbers of the first, second, and third scintillators hit by the muon in any muon penetration event, determine the azimuth angles of the first, second, and third scintillators hit by the muon. S2. Determine the incident and exit points of the muon based on the azimuth angle of the first scintillator hit by the muon. Axis coordinate values; The incident and exit points of the muon are determined based on the azimuth angles of the second and third scintillators hit by the muon. Axis coordinate values; S3. Based on the incident and exit points of the muon The axis coordinates determine the path of the muon; Among them, the scintillators hit by the muon include the scintillators that are incident on the muon and the scintillators that are ejected from the muon; In step S1, the azimuth angles of the first, second, and third scintillators hit by the muon are determined according to the following formula: ； ； ； In the formula, , , These are the azimuth angles of the first, second, and third scintillators hit by the muon, respectively. , , These represent the azimuth increments of each scintillator in the first, second, and third scintillator layers as a function of the circumference. , , These are the numbers of the first, second, and third scintillators that were hit by the muon; In step S2, the incident point and exit point of the muon are determined according to the following formula. Axis coordinate values: ； ； The incident and exit points of the muon are determined using the following formula. Axis coordinate values: ； In the formula, The helix angle of the scintillator; , The radii of the first scintillator layer, the second scintillator layer, and the third scintillator layer, respectively; , These are the azimuth angles of the first, second, and third scintillators that were hit by the muon.

2. The muon track reconstruction method based on a muon detector according to claim 1, characterized in that, Steps S1 and S2 also include: normalizing the azimuth angle to normalize its value to a specified value. Within the range.

3. The muon track reconstruction method based on a muon detector according to claim 1, characterized in that, The steps between S2 and S3 also include: ... The axis coordinate values ​​are corrected to eliminate axial deviations introduced by multiple ring numbering.

4. An imaging method based on a muon detector, characterized in that, Includes the following steps: The muon flux is obtained from the tracks of multiple muons; The muon transmittance on each track was calculated by comparing it with the muon flux under conditions of no ore body or homogeneous rock mass. A voxel model covering the well was established, and the penetration length of each muon track in the model was correlated with the corresponding transmittance, thus constructing the physical relationship between path integral density and transmittance. Algebraic reconstruction and inversion were used to jointly solve for the Muzi track and obtain the density distribution of the rock mass. Based on the density distribution of the rock mass, areas with significant density differences from the surrounding rock mass are identified, and these areas are determined to be mineral resource occurrence spaces. The muon tracks are obtained by the muon track reconstruction method based on a muon detector as described in any one of claims 1-3.

5. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-3.

6. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1-3.

7. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1-3.

Images