High-speed nuclear pulse signal acquisition system for multiple measurement of fast neutrons and acquisition method of high-speed nuclear pulse signal acquisition system

Abstract

The invention discloses a high-speed nuclear pulse signal acquisition system and method for multiple measurement of fast neutrons, and the system mainly consists of a pre-amplification module, a high-speed acquisition module, a synchronous triggering module, an Ethernet communication module, a high-voltage power module, and a low-voltage power module. According to the acquisition system, multiple paths of synchronous trigger signals are fanned out through the synchronous trigger module and serve as time starting signals of nuclear pulse sequences acquired by the high-speed acquisition module, then time starting points of all the nuclear pulse signals are synchronized, and the time interval between the time starting signals and the subsequent nuclear pulse sequences is calculated, so that the nuclear pulse sequences are acquired. Therefore, all nuclear pulse signals are marked with ns-level timestamps, and accurate collection of nuclear pulse time information is finally realized. According to the invention, the collection efficiency and collection precision of the high-speed nuclear pulse signal under the conditions of high counting rate and high case rate are obviously improved, and the accuracy of nuclear material nondestructive testing is further improved.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing of nuclear materials, and in particular to a high-speed nuclear pulse signal acquisition system and acquisition method for fast neutron multiplicity measurement. Background Technology

[0002] Nuclear material testing is crucial throughout the nuclear fuel cycle, serving as a vital basis for cost accounting, process control, and quality assurance in nuclear fuel reprocessing plants. It is also a key aspect of nuclear material accounting and nuclear safeguards oversight. Neutrons and gamma rays generated during nuclear fission possess excellent penetrating power and carry important characteristic information about fission nuclides. By measuring and analyzing the multiplicity distribution of fission neutrons, the mass of fissionable materials can be rapidly and accurately determined without the need for standard sample calibration, providing an effective and feasible technical approach for nuclear material testing.

[0003] Traditional thermal neutron multiplicity measurement systems employ 3 Helium counters, as detectors, are complex in structure, expensive, and time-consuming. In recent years, due to the increasing reserves of nuclear waste and the rapid development of nuclear fuel cycle technology, thermal neutron measurement systems have become insufficient to meet current detection needs. In contrast, fast neutron multiplexing measurement systems use scintillator detectors, which can completely preserve information about neutrons and gamma rays produced by nuclear fission, and have a shorter measurement time, giving them a significant advantage over traditional thermal neutron multiplexing measurement systems.

[0004] However, existing fast neutron multiplexing measurement systems are limited by the performance constraints of the pulse acquisition system. When acquiring nuclear pulse timing information, the timing start points of the pulse sequences in different acquisition channels are not synchronized and there is a delay between them, resulting in inaccurate acquisition of timing information. A large amount of information from fission neutrons and gamma rays is not effectively utilized, which has become a technical bottleneck for current fast neutron multiplexing measurement systems in nuclear material detection. Summary of the Invention

[0005] The purpose of this invention is to provide a high-speed nuclear pulse signal acquisition system and method for fast neutron multiplicity measurement. By designing each module of the acquisition system and improving the method for acquiring nuclear pulse time information, the invention solves the problems of insufficient information acquisition accuracy and low information acquisition efficiency of existing fast neutron multiplicity measurement systems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The high-speed nuclear pulse signal acquisition system for fast neutron multiplicity measurement mainly includes a preamplifier module, a high-speed acquisition module, a synchronous trigger module, an Ethernet communication module, a high-voltage power supply module, and a low-voltage power supply module. The preamplifier module includes several single-channel amplifiers based on transimpedance amplifier circuits, used to amplify the output signal of the detector; the relationship between the amplifier output signal and the input signal is as follows: ;in, It is the detector's output current signal. It is the transresistance value, representing the amplification factor. This is the voltage signal output after amplification; The high-speed acquisition module includes several signal acquisition channels, an ADC acquisition circuit, an FPGA, and an Ethernet port, which are used to access the output signal of the preamplifier circuit for digital acquisition. The synchronous triggering module includes a fan-out circuit, which is used to receive the trigger signal from the high-speed acquisition module, fan it out into multiple synchronous trigger signals, and then return them to the multiple signal acquisition channels of the high-speed acquisition module as time start signals. The Ethernet communication module includes an Ethernet data switch, which is connected to the high-speed acquisition module and the host computer via optical fiber, and is used to realize UDP communication between the high-speed acquisition module and the host computer. The high-voltage power supply module is used to provide the working voltage for the detector and communicates with the host computer to control the output voltage. The low-voltage power supply module is used to provide the required operating voltage for the preamplifier module, high-speed acquisition module, synchronous trigger module, Ethernet communication module and high-voltage power supply module.

[0007] This invention further provides a method for acquiring high-speed nuclear pulse signals for fast neutron multiplexing measurements. First, the preamplifier module of the acquisition system receives and amplifies the detector output signal. Then, the host computer sends a command to the high-speed acquisition module via the UDP protocol. Upon receiving the command, the high-speed acquisition module generates a trigger signal through the FPGA and sends it to the synchronization trigger module. The synchronization trigger module fans out the signal into multiple synchronization trigger signals and returns them to the high-speed acquisition module. Subsequently, the host computer sends another command to the high-speed acquisition module. The high-speed acquisition module uses the multiple synchronization trigger signals as the time start signals for several signal acquisition channels to begin digitally acquiring nuclear pulse signals. It also timestamps all nuclear pulse signals at the nanosecond level by calculating the time interval between the time start signal and the subsequent nuclear pulse sequence. Finally, the acquired signals are uploaded to the host computer and saved via the Ethernet communication module.

[0008] Compared with the prior art, the present invention has the following advantages: (1) The present invention achieves forced synchronization of the time start point of all nuclear pulse sequences through the synchronous triggering module, avoiding the timing delay caused by clock asynchrony, greatly improving the acquisition efficiency and accuracy of the nuclear pulse signal acquisition system, realizing high-speed acquisition of a large amount of neutron and γ-ray information generated by nuclear material fission under high event rate, improving the efficiency of information acquisition by the fast neutron multiplicity measurement device, and improving the accuracy of non-destructive testing of nuclear materials. (2) This invention integrates multiple functions such as high voltage output, signal amplification, digital acquisition and Ethernet communication through the design of the internal electronic system. It is different from the existing nuclear pulse signal acquisition device, realizes the innovation of device design, and realizes the rapid and accurate measurement of fast seed multiplicity. Attached Figure Description

[0009] Figure 1 This is a structural block diagram of the data acquisition system of the present invention; Figure 2 This is a structural block diagram of the data acquisition system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the nuclear pulse time information acquisition process of the present invention. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0011] like Figure 1 , Figure 2 As shown, a high-speed nuclear pulse signal acquisition system for fast neutron multiplicity measurement includes a preamplifier module, a high-speed acquisition module, a synchronous triggering module, an Ethernet communication module, a high-voltage power supply module, and a low-voltage power supply module. All of these modules are installed inside a 9U chassis.

[0012] The preamplifier module includes 20 single-channel amplifiers based on transimpedance amplifier circuits, used to amplify the detector's output signal. The preamplifier module is mounted on the inner wall of the chassis and connected to the ±5V power supply output from the low-voltage power module via a 5V-3pin power cable. It is connected to the BNC connector via an SMA to BNC adapter and then to the detector's output signal.

[0013] The high-speed acquisition module includes 20 signal acquisition channels, an ADC acquisition circuit, an FPGA, and an Ethernet port. Mounted on a liner inside the chassis, behind the preamplifier module, the high-speed acquisition module receives the amplified output signal from the preamplifier module via an SMA signal line for digital acquisition. It also receives the fan-out signal from the synchronization trigger module, communicates with the host computer via an Ethernet communication module connected by fiber optic cable, and receives the 12V output from the low-voltage power supply module via a power cable.

[0014] The synchronous trigger module is installed on the liner inside the chassis, behind the high-speed acquisition module. It receives the trigger signal generated by the high-speed acquisition module through the SMA signal line, and then fans out the signal into multiple synchronous trigger signals and returns them to the high-speed acquisition module.

[0015] The Ethernet communication module is installed on the liner inside the chassis, behind the synchronous trigger module. It connects the high-speed acquisition module and the host computer via optical fiber, enabling UDP communication between the high-speed acquisition module and the host computer, and uploading the acquired data to the host computer for storage.

[0016] The high-voltage power supply module is used to power the detector. It is installed on the liner inside the chassis, located to the left of the Ethernet communication module. It uses an FPGA chip as the main control chip and is connected to the high-voltage connector via a power cable. It can output 20 voltage channels simultaneously, with a single output voltage range of 0 to 2000V. It is connected to the serial communication interface via an RS485 communication line and communicates with the host computer via the UART protocol to realize program control of the voltage output value.

[0017] The low-voltage power supply module is installed on the inner wall of the chassis, to the right of the Ethernet communication module. It is powered by 220V and can simultaneously output 20 channels of 12V voltage and 20 channels of ±5V voltage. It is connected to the preamplifier module, high-speed acquisition module, synchronous trigger module, Ethernet communication module and high-voltage power supply module through power cables to provide them with operating voltage.

[0018] The high-speed pulse signal acquisition system of this invention acquires nuclear pulse sequence time information as follows: Figure 3As shown, specifically: the preamplifier module receives and amplifies the output signal of the detector; the host computer sends a command to the high-speed acquisition module via UDP protocol; after receiving the command, the high-speed acquisition module generates a trigger signal through the FPGA and sends it to the synchronization trigger module; the synchronization trigger module fans out the signal into multiple synchronization trigger signals and returns them to the high-speed acquisition module; subsequently, the host computer sends another command to the high-speed acquisition module; the high-speed acquisition module uses the multiple synchronization trigger signals as the time start signals for several signal acquisition channels to begin digital acquisition of the nuclear pulse signal; and timestamps all nuclear pulse signals at the nanosecond level by calculating the time interval between the time start signal and the subsequent nuclear pulse sequence; finally, the acquired signal is uploaded to the host computer and saved via the Ethernet communication module.

[0019] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-speed nuclear pulse signal acquisition system for fast neutron multiplicity measurement, characterized in that, It includes a preamplifier module, a high-speed acquisition module, a synchronous trigger module, an Ethernet communication module, a high-voltage power supply module, and a low-voltage power supply module; The preamplifier module includes several single-channel amplifiers based on transimpedance amplifier circuits, which are used to amplify the output signal of the detector. The high-speed acquisition module includes several signal acquisition channels, an ADC acquisition circuit, an FPGA, and an Ethernet port, which are used to access the output signal of the preamplifier circuit for digital acquisition. The synchronous triggering module includes a fan-out circuit, which is used to receive the trigger signal from the high-speed acquisition module, fan it out into multiple synchronous trigger signals, and then return them to the multiple signal acquisition channels of the high-speed acquisition module as time start signals. The Ethernet communication module includes an Ethernet data switch, which is connected to the high-speed acquisition module and the host computer via optical fiber, and is used to realize UDP communication between the high-speed acquisition module and the host computer. The high-voltage power supply module is used to provide the working voltage for the detector and communicates with the host computer to control the output voltage. The low-voltage power supply module is used to provide the required operating voltage for the preamplifier module, high-speed acquisition module, synchronous trigger module, Ethernet communication module and high-voltage power supply module.

2. A method for acquiring high-speed nuclear pulse signal acquisition systems for fast neutron multiplicity measurement based on claim 1, characterized in that, The preamplifier module of the acquisition system amplifies the output signal of the detector. The host computer sends a command to the high-speed acquisition module via UDP protocol. After receiving the command, the high-speed acquisition module generates a trigger signal through FPGA and sends it to the synchronous trigger module. The synchronous trigger module fans out the signal into multiple synchronous trigger signals and returns them to the high-speed acquisition module. Subsequently, the host computer sends another command to the high-speed acquisition module. The high-speed acquisition module uses the multiple synchronous trigger signals as the time start signals for several signal acquisition channels to start digital acquisition of nuclear pulse signals. It timestamps all nuclear pulse signals at the nanosecond level by calculating the time interval between the time start signal and the subsequent nuclear pulse sequence. Finally, the acquired signals are uploaded to the host computer and saved via Ethernet communication module.

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