Dual-channel forming method and system for nuclear signal processing

Abstract

The invention discloses a dual-channel forming method and system for nuclear signal processing. The method comprises the following steps: carrying out parallel processing on a digital nuclear pulse signal; the flat tip peak is formed to generate a signal with a flat top and a narrow pulse width feature, the flat top provides a stable sampling window to resist ballistic loss, and the narrow pulse width effectively reduces the pulse accumulation probability under a high counting rate; accurate timing triggering is achieved through symmetrical zero-area trapezoid forming by means of the stable zero crossing point characteristic that the output waveform is irrelevant to the input amplitude, the zero-area characteristic of symmetrical zero-area trapezoid forming further provides automatic baseline recovery capacity, and the defect that a traditional triggering mode is affected by amplitude fluctuation and baseline drift is overcome. Carrying out accumulation discrimination based on the zero crossing point signal to determine an effective event, and obtaining a net amplitude value at the peak value of the flat tip peak signal through delay sampling; therefore, the problem that energy and timing precision are difficult to consider in nuclear signal processing is effectively solved, and synchronous improvement of energy extraction precision and timing reliability at a high counting rate is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of nuclear radiation detection signal processing, specifically relating to a dual-channel shaping method and system for nuclear signal processing. Background Technology

[0002] In the field of nuclear radiation detection, filtering and shaping is a crucial step in nuclear signal processing. Its main purpose is to accurately extract voltage amplitude information proportional to the radiation energy from the weak current pulses output by the detector. Currently, the trapezoidal shaping algorithm is widely used due to its good anti-ballistic defect performance and high energy extraction accuracy. However, this algorithm has inherent drawbacks such as a wide output pulse width and a long dead time. In high-count-rate applications, excessively wide pulses significantly increase the probability of pulse stacking, i.e., overlapping pulses, which easily causes amplitude extraction distortion, limiting the accuracy of energy spectrum measurement and count throughput. To alleviate the stacking problem, the industry typically adopts a strategy of shortening the shaping time, but this inevitably sacrifices the signal-to-noise ratio and energy resolution. Furthermore, accurate pulse arrival time identification (i.e., triggering) is also crucial for nuclear signal processing. Traditional fixed-level triggering methods are easily affected by noise interference and pulse amplitude variations, leading to false triggers and missed triggers at high count rates, resulting in limited timing accuracy. Therefore, a nuclear signal processing scheme that can balance timing accuracy with low stacking and high-precision amplitude extraction at high count rates is needed. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a dual-channel shaping method and system for nuclear signal processing, which solves the technical problem that it is difficult to balance energy and timing accuracy in the existing nuclear signal processing methods, and achieves the effect of synergistic optimization and improved reliability of nuclear signal processing.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A dual-channel shaping method for nuclear signal processing includes the following steps:

[0006] 1) The pulse signal output by the nuclear radiation detector is amplified and converted from analog to digital to obtain a digital signal;

[0007] 2) Perform flat-top peak shaping and symmetrical zero-area trapezoidal shaping on the digital signal in parallel; flat-top peak shaping converts the digital signal into a flat-top peak signal with flat-top characteristics for pulse amplitude extraction, and symmetrical zero-area trapezoidal shaping converts the digital signal into a zero-crossing signal with zero crossing points for pulse arrival time identification.

[0008] 3) Detect the zero-crossing point of the zero-crossing signal, determine the pulse arrival time, and perform accumulation discrimination based on the pulse time interval to determine the valid event;

[0009] 4) For the valid event, perform delayed sampling at the peak of the flat-top peak signal and subtract the baseline value to obtain the net amplitude value.

[0010] Furthermore, in step 1), before performing analog-to-digital conversion on the pulse signal, the amplified pulse signal is also subjected to analog conditioning.

[0011] Furthermore, in step 2), the flat-top peak shaping process is achieved by executing the following time-domain recursive difference equation:

[0012] δ(n) = x(n) - ax(n-1)

[0013] p(n)=p(n-1)+δ(n)-δ(nn a )-δ(nn b -2)+δ(nn c -2)

[0014] q(n) = q(n-1) + p(n) - n a [δ(nn a )-δ(nn b -1)]

[0015]

[0016] y(n) = y(n-1) + r(n)

[0017] Where δ(n) is the unit impulse function, n is the discrete-time index representing the nth sampling point, x(n) is the digital signal, and a = e -ΔT / τ e is the natural constant, ΔT is the sampling period, τ is the attenuation coefficient, and n a n is the rise time of the peak signal at the flat peak. b n is the sum of the rise time and the flat-top time of the peak signal. c y(n) is the sum of the rise time, flat time, and fall time of the flat-top peak signal. p(n) is obtained by accumulating δ(n), q(n) is obtained by accumulating p(n), r(n) is obtained by accumulating q(n), and y(n) is obtained by accumulating r(n). y(n) is the flat-top peak signal.

[0018] Furthermore, in step 2), the symmetric zero-area trapezoidal forming process is achieved by executing the following time-domain recursive difference equation:

[0019] δ(n) = x(n) - ax(n-1)

[0020] p(n)=δ(n)-δ(nJ)-δ(nJK)+δ(n-2J-K)

[0021] q(n) = q(n-1) + p(n)

[0022] r(n) = r(n-1) + p(n)

[0023] z(n) = -r(n) + 2r(nL) - r(n-2L)

[0024] Where J is the number of hypotenuse points of the trapezoid, K is the number of flat vertices of the trapezoid, z(n) is the zero-crossing signal, and L is the number of base points of the trapezoid, L=2J+K.

[0025] Further, in step 3), the stacking judgment is: determine whether the time interval between the current pulse and the pulse corresponding to the previous valid event is greater than a preset threshold. If it is greater, then determine that the current pulse corresponds to a valid event.

[0026] Further, in step 4), the delayed sampling is: after detecting the zero crossing, wait for a preset delay time to ensure that the sampling point accurately corresponds to the peak position of the flat-top peak signal.

[0027] Further, in step 4), the baseline value is obtained by the following baseline estimation method: dynamically judging the density of the pulse sequence, calculating the baseline value in the signal region before its rising edge for isolated or far-spaced pulses; and using the baseline value of the previous valid event for continuously arriving pulses.

[0028] The present invention also includes a dual-channel shaping system for nuclear signal processing, used to implement the dual-channel shaping method for nuclear signal processing as described above. The dual-channel shaping system for nuclear signal processing includes a preamplifier, an analog-to-digital converter (ADC), a field-programmable gate array (FPGA), and an output interface. The preamplifier is connected to a nuclear radiation detector and amplifies the pulse signal output by the detector. The ADC is connected to the preamplifier and converts the amplified pulse signal into a digital signal. The FPGA is connected to the ADC and configured to include a flat-top peak shaping module, a symmetrical zero-area trapezoidal shaping module, a control logic module, and an output interface. The flat-top peak shaping module receives the digital signal and performs flat-top peak shaping processing. The symmetrical zero-area trapezoidal shaping module receives the digital signal and performs symmetrical zero-area trapezoidal shaping processing. The control logic module is connected to both the flat-top peak shaping module and the symmetrical zero-area trapezoidal shaping module and is used to detect the zero-crossing point of the zero-crossing signal, perform accumulation discrimination, control delay sampling, and subtract baseline values. The output interface is connected to the control logic module and outputs the net amplitude value.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The dual-channel shaping method for nuclear signal processing described in this invention achieves high-precision energy extraction and timing triggering simultaneously by processing digitized nuclear pulse signals in parallel. Flat-topped peak shaping generates signals with flat tops and narrow pulse widths. The flat top provides a stable sampling window for amplitude measurement, effectively resisting ballistic defects, while the narrow pulse characteristic significantly reduces the probability of pulse accumulation at high count rates. Simultaneously, symmetrical zero-area trapezoidal shaping utilizes its stable zero-crossing point characteristic, where the output waveform is independent of the input amplitude, to achieve precise timing triggering. Its inherent zero-area characteristic also provides automatic baseline recovery capability, effectively overcoming the shortcomings of traditional triggering methods affected by amplitude fluctuations and baseline drift. Accumulation discrimination is performed based on the zero-crossing signal of the symmetrical zero-area trapezoid to determine valid events, and then the net amplitude value is obtained at the peak of the flat-topped peak signal through delayed sampling. This effectively solves the problem of balancing energy and timing accuracy in existing nuclear signal processing, achieving simultaneous improvement in energy extraction accuracy and timing trigger reliability under high count rate environments, and achieving a comprehensive effect of suppressing pulse accumulation, improving energy resolution, and enhancing timing accuracy. Attached Figure Description

[0031] Figure 1 A comparison diagram of the first forming process of traditional trapezoidal forming and flat-topped peak forming;

[0032] Figure 2 A comparison diagram of the second forming process between traditional trapezoidal forming and flat-topped peak forming;

[0033] Figure 3 A comparison diagram of the forming processes of flat-topped peak forming and symmetrical zero-area trapezoidal forming;

[0034] Figure 4 A schematic diagram of the transfer function model for flat-top peak formation;

[0035] Figure 5 This is a schematic diagram of the first integration result during the flat-top peak forming process;

[0036] Figure 6 This is a schematic diagram of the second integration result during the flat-top peak forming process;

[0037] Figure 7 This is a schematic diagram of the third integration result during the flat-top peak forming process;

[0038] Figure 8 This is a schematic diagram of the fourth integration result during the flat-top peak forming process; Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0040] Example:

[0041] A dual-channel shaping method for nuclear signal processing includes the following steps:

[0042] 1) The pulse signal output by the nuclear radiation detector is amplified and converted from analog to digital to obtain a digital signal;

[0043] 2) Perform flat-top peak shaping and symmetrical zero-area trapezoidal shaping on the digital signal in parallel; flat-top peak shaping converts the digital signal into a flat-top peak signal with flat-top characteristics for pulse amplitude extraction, and symmetrical zero-area trapezoidal shaping converts the digital signal into a zero-crossing signal with zero crossing points for pulse arrival time identification.

[0044] 3) Detect the zero-crossing point of the zero-crossing signal, determine the pulse arrival time, and perform accumulation discrimination based on the pulse time interval to determine the valid event;

[0045] 4) For the valid event, perform delayed sampling at the peak of the flat-top peak signal and subtract the baseline value to obtain the net amplitude value.

[0046] The pulse signal output by the nuclear radiation detector is a weak exponentially decaying pulse signal. Amplification converts it into an exponentially decaying pulse signal with a higher voltage amplitude that is easier to process, without changing its essential exponential decay nature. The amplified exponentially decaying pulse signal is an analog signal, and analog-to-digital conversion is used to convert the analog signal into a digital signal so that the digital chip can understand and perform calculations.

[0047] Among them, the flat-top peak shaping algorithm is an algorithm focused on optimizing pulse energy extraction performance. It uses a specific digital filtering design to shape exponentially decaying pulses into pulse waveforms with a flat top, steep sides, and significantly narrower overall pulse width. The flat top provides an ideal time window for stable amplitude sampling, which can effectively resist ballistic defects and ensure the accuracy of energy extraction. The significantly narrowed pulse width directly reduces the dead time of the system, thereby reducing the probability of pulse accumulation at high count rates. However, the zero-crossing characteristics of this algorithm are not obvious or are amplitude-dependent, and it is weak for timing trigger selection.

[0048] As attached Figure 1 and attached Figure 2As shown, the pulse waveform shaped by the traditional ladder forming algorithm produces pulse accumulation due to the small arrival time interval of the original pulses. This directly leads to the degradation of energy resolution and is an inherent defect in high count rate and timing inaccurate scenarios. In contrast, the flat-top forming algorithm only produces pulse accumulation when the pulse interval is even smaller, thus outputting flat-top pulses with stable amplitude. This indicates that the algorithm has excellent energy resolution and can provide higher resolution energy measurement results.

[0049] Among them, the symmetric zero-area trapezoidal shaping algorithm is an excellent timing method. It can generate pulse output waveforms that are independent of the input pulse amplitude and have stable zero-crossing points, thus providing high timing accuracy and good baseline recovery capability. However, the algorithm itself is not designed for energy extraction and cannot directly output pulse amplitude information that can be used for energy spectrum analysis; see attached. Figure 3 As shown, its output waveform has symmetrical and zero-crossing stability, but it does not have a flat top structure and is not suitable for precise amplitude sampling.

[0050] The dual-channel shaping method for nuclear signal processing described in this invention converts the pulse signal output by the nuclear radiation detector into a digital signal, and then performs flat-top peak shaping and symmetrical zero-area trapezoidal shaping in parallel. Flat-top peak shaping generates a signal with a flat top and narrow pulse width, specifically optimizing the pulse amplitude extraction process. The flat top provides a stable sampling window for amplitude measurement to resist ballistic defects, while the significantly narrowed pulse width reduces the probability of pulse accumulation at high count rates. Simultaneously, the symmetrical zero-area trapezoidal shaping utilizes its stable zero-crossing characteristic, where the output waveform is independent of the input amplitude, to specifically handle precise timing triggering, and its inherent... The zero-area characteristic also brings automatic baseline recovery capability, which can effectively overcome the defects of traditional triggering methods affected by amplitude fluctuations and baseline drift. Then, based on the zero-crossing signal of the symmetrical zero-area trapezoidal formation, the accumulation discrimination is performed to determine the valid event. Finally, based on the valid event, the peak value of the flat-top peak signal is delayed and sampled, and the baseline value is subtracted to ensure that the accurate net amplitude value is obtained at the optimal time. This can effectively solve the problem that it is difficult to balance energy and timing accuracy in existing nuclear signal processing methods, thereby achieving a simultaneous improvement in energy extraction accuracy and timing trigger reliability in high count rate environments, and achieving the effects of suppressing pulse accumulation, improving energy resolution, and improving timing accuracy.

[0051] In step 1), before performing analog-to-digital conversion on the pulse signal, the amplified pulse signal is also subjected to analog conditioning; specifically, the analog conditioning may include, but is not limited to, low-pass filtering, high-pass filtering, and pole-zero cancellation, etc., and the analog conditioning is used to enhance the characteristics of the pulse signal and reduce noise interference.

[0052] In step 2), the flat-top peak shaping process first deconvolves the digital signal into a unit impulse pulse, and then achieves pulse shaping by synthesizing the impulse response with the desired pulse shape. Its transfer function model is as follows: Figure 4 As shown; the flat-top peak shaping process is achieved by executing the following time-domain recursive difference equation:

[0053] δ(n) = x(n) - ax(n-1)

[0054] p(n)=p(n-1)+δ(n)-δ(nn a )-δ(nn b -2)+δ(nn c -2)

[0055] q(n) = q(n-1) + p(n) - n a [δ(nn a )-δ(nn b -1)]

[0056]

[0057] y(n) = y(n-1) + r(n)

[0058] Where δ(n) is the unit impulse function, n is the discrete-time index representing the nth sampling point, x(n) is the digital signal, and a = e -ΔT / τ e is the natural constant, ΔT is the sampling period, τ is the attenuation coefficient, and p(n) is obtained by accumulating and synthesizing δ(n). Its pulse shape can be found in [reference needed]. Figure 5 As shown, q(n) is obtained by accumulating and synthesizing p(n), and its pulse shape can be found in [reference]. Figure 6 As shown, r(n) is obtained by accumulating and synthesizing q(n), and its pulse shape can be found in [reference]. Figure 7 As shown, y(n) is obtained by accumulating and synthesizing r(n). y(n) is a flat-topped signal, and its pulse shape can be found in [reference needed]. Figure 8 As shown; n a n b and n c These are the shape parameters of the flat-top peak shaping algorithm. They are integer constants in units of the number of sampling points, and their values ​​collectively determine the specific shape of the final generated flat-top peak pulse. n a n is the rise time of the peak signal at the flat peak. a It is the key parameter that determines the rising edge or the flat-top start point of the pulse, n b n is the sum of the rise time and the flat-top time of the peak signal. a With n b The difference determines the duration of the flat top, n cn is the sum of the rise time, flattening time, and fall time of the peak signal. c With n b The difference is used to control the shape of the pulse falling edge or the characteristics of the pulse tail, ensuring pulse area or symmetry.

[0059] In step 2), the symmetrical zero-area trapezoidal forming process can effectively eliminate the DC offset and dynamic changes of the digital signal baseline because its transfer function can make the area after the first integration and the second integration both zero, thus achieving automatic baseline recovery and effectively suppressing baseline drift and fluctuation. Therefore, it plays a key role in pulse triggering and stacking discrimination.

[0060] Symmetric zero-area trapezoidal shaping is achieved by executing the following time-domain recursive difference equation:

[0061] δ(n) = x(n) - ax(n-1)

[0062] p(n)=δ(n)-δ(nJ)-δ(nJK)+δ(n-2J-K)

[0063] q(n) = q(n-1) + p(n)

[0064] r(n) = r(n-1) + p(n)

[0065] z(n) = -r(n) + 2r(nL) - r(n-2L)

[0066] Where J is the number of hypotenuse points of the trapezoid, K is the number of flat vertices of the trapezoid, z(n) is the zero-crossing signal, and L is the number of base points of the trapezoid, L=2J+K.

[0067] In step 3), the accumulation judgment is: determine whether the time interval between the current pulse and the pulse corresponding to the previous valid event is greater than a preset threshold. If it is greater, the current pulse is determined to correspond to a valid event. This mechanism can filter out pulses that are distorted due to severe accumulation in the early stage, ensuring that only qualified pulses enter the subsequent processing flow.

[0068] The preset threshold is the dead time mentioned in the background technology. In this solution, the preset threshold must be greater than or equal to the total time required from the pulse arrival time (trigger time) to the system completing the amplitude extraction and processing of the pulse. This total time mainly includes: the peak delay time of the flat-top pulse: due to the inherent delay in the formation of the flat-top pulse, its peak point will lag behind the trigger point, and the peak sampling and data processing time: the time required for the system to sample at the peak point, subtract the baseline, and output the net amplitude value; only when this time window ends is the system ready to receive and process the next pulse without confusion.

[0069] Correspondingly, the specific logic of the stacking judgment is as follows: if the time interval between the current pulse and the previous pulse is greater than a preset threshold, it means that the previous pulse has been processed and the system is ready. The current pulse is regarded as a valid event and enters the amplitude extraction process. If the time interval between the current pulse and the previous pulse is less than or equal to the preset threshold, it means that the previous pulse has not been processed. The arrival of the current pulse will cause pulse stacking. At this time, the system will determine that the current pulse is an invalid event and discard it to prevent it from generating incorrect amplitude information, thereby ensuring the accuracy of energy spectrum measurement.

[0070] In step 4), the baseline value is obtained through the following baseline estimation method: dynamically determine the density of the pulse sequence, calculate the baseline value in the signal region before the rising edge of isolated or far-spaced pulses; for continuously arriving pulses, use the baseline value of the previous valid event; this method of combining "look-ahead calculation" and "baseline preservation" can effectively overcome the measurement error caused by incomplete baseline recovery at high count rates.

[0071] In step 4), the delayed sampling is performed as follows: after detecting the zero crossing, a preset delay time is waited to ensure that the sampling point accurately corresponds to the peak position of the flat-top peak signal. This is because the filter used to achieve flat-top peak shaping generally has an inherent delay, and its peak point will lag behind the trigger time (arrival time). Therefore, after the arrival time, a delay is inserted to ensure that the sampling point accurately falls on the peak position of the flat-top peak waveform. At this precise moment, the system samples the peak value and immediately subtracts the baseline value, finally outputting an accurate and pure pulse net amplitude value for subsequent energy spectrum analysis.

[0072] The present invention also includes a dual-channel shaping system for nuclear signal processing. The dual-channel shaping system is used to implement the dual-channel shaping method for nuclear signal processing as described above. The dual-channel shaping system includes a preamplifier, an analog-to-digital converter (ADC), a field-programmable gate array (FPGA), and an output interface. The preamplifier is connected to a nuclear radiation detector and is used to amplify the pulse signal output by the detector. The ADC is connected to the preamplifier and is used to convert the amplified pulse signal into a digital signal. The FPGA is connected to the ADC and is configured to include a flat-top peak shaping module, a symmetrical zero-area trapezoidal shaping module, a control logic module, and an output interface. The flat-top peak shaping module receives the digital signal and performs flat-top peak shaping processing. The symmetrical zero-area trapezoidal shaping module receives the digital signal and performs symmetrical zero-area trapezoidal shaping processing. The control logic module is connected to both the flat-top peak shaping module and the symmetrical zero-area trapezoidal shaping module and is used to detect the zero-crossing point of the zero-crossing signal, perform accumulation discrimination, control delay sampling, and subtract baseline values. The output interface is connected to the control logic module and is used to output a net amplitude value to an energy spectrum analysis device.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A dual-channel shaping method for nuclear signal processing, characterized in that: Includes the following steps: 1) The pulse signal output by the nuclear radiation detector is amplified and converted from analog to digital to obtain a digital signal; 2) Perform flat-top peak shaping and symmetrical zero-area trapezoidal shaping processes on the digital signals in parallel; Flat-top peak shaping process converts digital signals into flat-top peak signals with flat-top characteristics for pulse amplitude extraction, while symmetrical zero-area trapezoidal shaping process converts digital signals into zero-crossing signals with zero-crossing points for pulse arrival time identification. 3) Detect the zero-crossing point of the zero-crossing signal, determine the pulse arrival time, and perform accumulation discrimination based on the pulse time interval to determine the valid event; 4) For the valid event, perform delayed sampling at the peak of the flat-top peak signal and subtract the baseline value to obtain the net amplitude value.

2. The dual-channel shaping method for nuclear signal processing according to claim 1, characterized in that: In step 1), before performing analog-to-digital conversion on the pulse signal, the amplified pulse signal is also subjected to analog conditioning.

3. The dual-channel shaping method for nuclear signal processing according to claim 1, characterized in that: In step 2), the flat-top peak shaping process is achieved by executing the following time-domain recursive difference equation: δ(n) = x(n) - ax(n-1) p(n)=p(n-1)+δ(n)-δ(nn a )-δ(nn b -2)+δ(nn c -2) q(n)=q(n-1)+p(n)-n a [δ(nn a )–δ(nn b −1)] y(n) = y(n-1) + r(n) Where δ(n) is the unit impulse function, n is the discrete-time index representing the nth sampling point, x(n) is the digital signal, and a = e -ΔT / τ e is the natural constant, ΔT is the sampling period, τ is the attenuation coefficient, and n a n is the rise time of the peak signal at the flat peak. b n is the sum of the rise time and the flat-top time of the peak signal. c y(n) is the sum of the rise time, flat time, and fall time of the flat-top peak signal. p(n) is obtained by accumulating δ(n), q(n) is obtained by accumulating p(n), r(n) is obtained by accumulating q(n), and y(n) is obtained by accumulating r(n). y(n) is the flat-top peak signal.

4. The dual-channel shaping method for nuclear signal processing according to claim 1, characterized in that: In step 2), the symmetric zero-area trapezoidal forming process is achieved by executing the following time-domain recursive difference equation: δ(n) = x(n) - ax(n-1) p(n)=δ(n)-δ(nJ)-δ(nJK)+δ(n-2J-K) q(n) = q(n-1) + p(n) r(n) = r(n-1) + p(n) z(n) = -r(n) + 2r(nL) - r(n-2L) Where J is the number of hypotenuse points of the trapezoid, K is the number of flat vertices of the trapezoid, z(n) is the zero-crossing signal, and L is the number of base points of the trapezoid, L=2J+K.

5. The dual-channel shaping method for nuclear signal processing according to claim 1, characterized in that: In step 3), the stacking judgment is: determine whether the time interval between the current pulse and the pulse corresponding to the previous valid event is greater than a preset threshold. If it is greater, then determine that the current pulse corresponds to a valid event.

6. The dual-channel shaping method for nuclear signal processing according to claim 1, characterized in that: In step 4), the delayed sampling is: after detecting the zero crossing, wait for a preset delay time to ensure that the sampling point accurately corresponds to the peak position of the flat-top peak signal.

7. The dual-channel shaping method for nuclear signal processing according to claim 1, characterized in that: In step 4), the baseline value is obtained by the following baseline estimation method: dynamically determine the density of the pulse sequence, calculate the baseline value in the signal region before its rising edge for isolated or far-spaced pulses; for continuously arriving pulses, use the baseline value of the previous valid event.

8. A dual-channel shaping system for nuclear signal processing, characterized in that: To implement the dual-channel shaping method for nuclear signal processing as described in any one of claims 1-7, the dual-channel shaping system for nuclear signal processing includes a preamplifier, an analog-to-digital converter, a field-programmable gate array, and an output interface; the preamplifier is connected to a nuclear radiation detector and is used to amplify the pulse signal output by the detector; An analog-to-digital converter (ADC) is connected to a preamplifier and is used to convert the amplified pulse signal into a digital signal. A field-programmable gate array (FPGA) is connected to the ADC and is configured to include a flat-top peak forming module, a symmetrical zero-area trapezoidal forming module, a control logic module, and an output interface. The flat-top peak forming module receives the digital signal and performs flat-top peak forming processing. The symmetrical zero-area trapezoidal forming module receives the digital signal and performs symmetrical zero-area trapezoidal forming processing. The control logic module is connected to both the flat-top peak forming module and the symmetrical zero-area trapezoidal forming module and is used to detect the zero-crossing point of the zero-crossing signal, perform accumulation discrimination, control the delay sampling, and subtract the baseline value. The output interface is connected to the control logic module and is used to output the net amplitude value.

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