CN-122017940-A - High-speed nuclear pulse signal acquisition system and method for fast neutron multiple measurement

CN122017940ACN 122017940 ACN122017940 ACN 122017940ACN-122017940-A

Abstract

The invention discloses a high-speed nuclear pulse signal acquisition system for fast neutron multiple measurement and an acquisition method thereof, wherein the acquisition system mainly comprises a pre-amplification 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 acquisition system fans out multi-channel synchronous trigger signals through the synchronous trigger module, and takes the multi-channel synchronous trigger signals as time starting signals of a nuclear pulse sequence acquired by the high-speed acquisition module, so that the time starting points of all the nuclear pulse signals are synchronized, ns-level time stamps are marked on all the nuclear pulse signals through calculating the time intervals of the time starting signals and the follow-up nuclear pulse sequence, and the accurate acquisition of the nuclear pulse time information is finally realized. The invention remarkably improves the acquisition efficiency and the acquisition precision of the high-speed nuclear pulse signal under the conditions of high counting rate and high case rate, and further improves the accuracy of nondestructive detection of nuclear materials.

Inventors

CHEN LIAN
LI JIATONG
WANG JUNYU
LEI HAOYU
LEI WENMING
LUO JIANDONG
HEI DAQIAN
LI JI
TANG YAJUN
CAI PINGKUN

Assignees

兰州大学
中国核动力研究设计院

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (2)

1. The high-speed nuclear pulse signal acquisition system for the fast neutron multiple measurement is characterized by comprising a pre-amplification 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 pre-amplification module comprises a plurality of single-channel amplifiers based on a transimpedance amplification circuit and is used for transimpedance amplification of an output signal of the access detector; The high-speed acquisition module comprises a plurality of paths of signal acquisition channels, an ADC acquisition circuit, an FPGA and an Ethernet port, and is used for accessing the output signals of the pre-amplification circuit to carry out digital acquisition; The synchronous trigger module comprises a fan-out circuit, a timing circuit and a timing circuit, wherein the fan-out circuit is used for accessing the trigger signal from the high-speed acquisition module, fanning out the trigger signal into a plurality of paths of synchronous trigger signals and returning the synchronous trigger signals to a plurality of paths of signal acquisition channels of the high-speed acquisition module to serve as time starting signals; the Ethernet communication module comprises an Ethernet data switch, is respectively connected with the high-speed acquisition module and the upper computer through optical fibers and is used for realizing UDP communication between the high-speed acquisition module and the upper computer; the high-voltage power supply module is used for providing working voltage for the detector and is in communication connection with the upper computer to control output voltage; the low-voltage power supply module is used for providing required working voltage for the pre-amplifying module, the high-speed acquisition module, the synchronous triggering module, the Ethernet communication module and the high-voltage power supply module.
2. The acquisition method of the high-speed nuclear pulse signal acquisition system for fast neutron multiple measurement is characterized in that a pre-amplification module of the acquisition system is connected with an output signal of a detector for amplification, an upper computer sends an instruction to the high-speed acquisition module through a UDP protocol, the high-speed acquisition module generates a trigger signal through an FPGA after receiving the instruction and sends the trigger signal to a synchronous trigger module, the synchronous trigger module fans out the signal into a plurality of paths of synchronous trigger signals and returns the signals to the high-speed acquisition module, then the upper computer sends the instruction to the high-speed acquisition module again, the high-speed acquisition module starts to digitally acquire nuclear pulse signals by taking the plurality of paths of synchronous trigger signals as time initial signals of a plurality of paths of signal acquisition channels, ns-level time stamp marks are carried out on all the nuclear pulse signals by calculating time intervals of the time initial signals and a subsequent nuclear pulse sequence, and finally acquired signals are uploaded to the upper computer through an Ethernet communication module and stored.

Description

High-speed nuclear pulse signal acquisition system and method for fast neutron multiple measurement Technical Field The invention relates to the field of nondestructive detection of nuclear materials, in particular to a high-speed nuclear pulse signal acquisition system and method for fast neutron multiple measurement. Background The nuclear material detection runs through each link of nuclear fuel circulation, is an important basis for the nuclear fuel post-treatment plant to carry out cost accounting, process control, quality assurance and other works, and is also a key investigation content of nuclear material balance and nuclear assurance supervision. Neutrons and gamma rays generated in the fission process of the nuclear material have good penetrating power and carry important characteristic information of fissile nuclides, and the quality of the fissile material can be rapidly and accurately obtained under the condition of no standard sample scale by measuring and analyzing the distribution of the multiple of the fissile neutrons, so that an effective and feasible technical approach is provided for the detection of the nuclear material. The traditional thermal neutron multiple measuring system adopts 3 He counting tubes as detectors, has complex structure, high cost and long measuring time, and in recent years, as the nuclear waste reserves are increased, the nuclear fuel circulation process is developed rapidly, and the thermal neutron measuring system has difficulty in meeting the current detection requirements. The fast neutron multiple measuring system uses the scintillator detector, the information of neutrons and gamma rays generated by fission can be completely reserved, the measuring time is short, and the fast neutron multiple measuring system has obvious advantages compared with the traditional thermal neutron multiple measuring system. However, the existing fast neutron multiple measurement system is limited by the performance limitation of the pulse acquisition system, when the nuclear pulse time information is acquired, the time starting points of pulse sequences of different acquisition channels are not synchronous, and delay exists between the time starting points, so that the acquisition of the time information is inaccurate, a large amount of information of fission neutrons and gamma rays is not effectively utilized, and the fast neutron multiple measurement system becomes a technical bottleneck in nuclear material detection. Disclosure of Invention The invention aims to provide a high-speed nuclear pulse signal acquisition system and a high-speed nuclear pulse signal acquisition method for fast neutron multiple measurement, which solve the problems of insufficient information acquisition accuracy and low information acquisition efficiency of the conventional fast neutron multiple measurement system in the background art by improving the design of each module of the acquisition system and the nuclear pulse time information acquisition method. In order to achieve the above purpose, the present invention provides the following technical solutions: the high-speed nuclear pulse signal acquisition system for the fast neutron multiple measurement mainly comprises a pre-amplification 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 pre-amplification module comprises a plurality of single-channel amplifiers based on a transimpedance amplification circuit and is used for transimpedance amplification of an output signal of the access detector, and the relation between the output signal and the input signal of the amplifier is as follows: Wherein, the method comprises the steps of, Is the output current signal of the detector,Is the trans-impedance value, represents the amplification factor,Is the amplified voltage signal; The high-speed acquisition module comprises a plurality of paths of signal acquisition channels, an ADC acquisition circuit, an FPGA and an Ethernet port, and is used for accessing the output signals of the pre-amplification circuit to carry out digital acquisition; The synchronous trigger module comprises a fan-out circuit, a timing circuit and a timing circuit, wherein the fan-out circuit is used for accessing the trigger signal from the high-speed acquisition module, fanning out the trigger signal into a plurality of paths of synchronous trigger signals and returning the synchronous trigger signals to a plurality of paths of signal acquisition channels of the high-speed acquisition module to serve as time starting signals; the Ethernet communication module comprises an Ethernet data switch, is respectively connected with the high-speed acquisition module and the upper computer through optical fibers and is used for realizing UDP communication between the high-speed acquisition module and the upper computer; the high-voltage power supply modu