Multifunctional signal processing device for nuclear measurement

Abstract

The invention relates to the technical field of nuclear radiation monitoring, and provides a multifunctional signal processing device for nuclear measurement, which comprises three signal conditioning modules respectively used for conditioning signals of three nuclear measurement detectors, the signal processing device comprises a signal processing module and a signal processing module, weak signals output by the signal processing module are shielded by a tri-coaxial cable and a connector and then enter corresponding channels to be amplified, filtered, subjected to gain adjustment and signal conditioning and then subjected to isolated output, the signal processing module further comprises a signal processing module, and the conditioned signals are sampled and counted by a high-speed ADC and a counter to form digital signals. The multifunctional signal processing device for nuclear measurement is used for processing output signals of various detectors of a nuclear measurement system, can carry out digital processing on weak pulse signals, weak current signals and stacked and overlapped charge pulses, and is simple and efficient.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear radiation monitoring, and in particular to a multifunctional signal processing device for nuclear measurement. Background Art

[0002] Nuclear measurement systems usually include nuclear radiation detectors and nuclear electronics measurement systems. The signal processing part of the nuclear electronics measurement system receives various analog signals from nuclear radiation detectors, and converts them into easily identifiable digital signals after amplification, shaping, sampling and other processing. The function, performance and reliability of the signal processing device will greatly affect the safety and reliability of the nuclear measurement system.

[0003] In the nuclear measurement system, nuclear radiation detectors mainly include counter tube detectors, fission ionization chamber detectors and boron-coated ionization chamber detectors. Different detectors will output various types of analog signals such as weak charge pulses, weak currents, and accumulated overlapping charge pulses under different working conditions. This requires a signal processing device that can process different types of analog signals to process them, so as to meet the nuclear measurement signal detection of multiple channels and obtain effective nuclear information.

[0004] At present, common signal processing devices for nuclear measurement can only process signals for one type of nuclear radiation detector, and their front ends need to be connected to a preamplifier, which has the following disadvantages or shortcomings: the measurement functions of various signal processing devices are relatively simple, and it is often necessary to equip multiple signal processing devices to meet the signal processing requirements of the entire nuclear measurement system, which increases the use cost and system failure rate; the front end of the signal processing device needs to be connected to a preamplifier, which increases the use of cables and connectors, affecting the reliability of the system. Summary of the invention

[0005] In order to overcome the shortcomings or deficiencies of the prior art, the present invention proposes a multifunctional signal processing device for nuclear measurement, which is used for processing the output signals of various detectors in the nuclear measurement system. It can digitally process weak pulse signals, weak current signals and accumulated overlapping charge pulses respectively, which is simple and efficient.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is as follows: a multifunctional signal processing device for nuclear measurement, the signal processing device digitizes the analog signals output by nuclear measurement counting tube detectors, fission ionization chamber detectors and boron-coated ionization chamber detectors, and displays the processed signals; the signal processing device includes three signal conditioning modules, which are respectively used for signal conditioning of three types of nuclear measurement detectors, and the weak signals output by them are shielded through three coaxial cables and connectors and enter the corresponding channels for amplification, filtering, gain adjustment, and signal conditioning and then isolated and output; the signal processing device also includes a signal processing module, which uses a high-speed ADC and a counter to sample and count the conditioned signals to form digital signals.

[0007] In the above technical scheme, the signal processing device includes a base plate, a test interface module, a signal processing module, an information display module, a status indication module, a low-voltage power supply module, an AC IN module, a communication I / O module, a switch quantity I / O module, an analog quantity I / O module, and a signal conditioning module, wherein the test interface module, the signal processing module, the information display module, the status indication module, and the low-voltage power supply module are installed on the front of the base plate through a 96-pin connector, and the AC IN module, the communication module, the switch quantity module, the analog quantity I / O module, and the signal conditioning module are installed on the rear of the base plate through a 96-pin connector. The signal conditioning module is replaced according to the type of detector actually used, including a counter tube type detector signal conditioning module, a fission ionization chamber type detector signal conditioning module, and a boron-coated ionization chamber type detector signal conditioning module.

[0008] The multifunctional signal processing device for nuclear measurement of the present invention is easy to use, does not need to be connected to other components, can be applied to the output signal processing of various detectors in the nuclear measurement system, can simultaneously perform digital processing on weak pulse signals, weak current signals and accumulated overlapping charge pulses, and can solve the problems that the existing signal processing devices have a single function, need to be equipped with multiple signal processing devices, and need to be connected to a preamplifier at the front end. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the front panel of the signal processing device of the present invention.

[0010] Figure 2 Schematic diagram of the rear panel of the signal processing device of the present invention.

[0011] Figure 3 This is a circuit schematic diagram of the signal conditioning module of the counting tube detector in the present invention.

[0012] Figure 4 This is a circuit schematic diagram of a signal conditioning module for a fission ionization chamber type detector in the present invention.

[0013] Figure 5 This is a circuit schematic diagram of a signal conditioning module for a boron-coated ionization chamber detector in the present invention.

[0014] Figure 6 This is a circuit schematic diagram of the signal processing module in the present invention. DETAILED DESCRIPTION

[0015] The implementation modes of the present invention are further described below in conjunction with the accompanying drawings and specific examples.

[0016] like Figure 1 , Figure 2 As shown, an embodiment of the present invention provides a multifunctional signal processing device for nuclear measurement, and the signal processing device consists of a baseboard, a test interface module, a signal processing module, an information display module, a status indication module, a low-voltage power supply module, an AC IN module, a communication I / O module, a switch quantity I / O module, an analog quantity I / O module, and a signal conditioning module.

[0017] The test interface module, signal processing module, information display module, status indication module, and low-voltage power supply module are installed on the front of the base plate through a 96-pin connector. Figure 1 shown.

[0018] The AC IN module, communication module, switch module, analog I / O module, and signal conditioning module are installed on the rear of the base plate through a 96-pin connector. Figure 2 shown.

[0019] All modules except the signal conditioning module are universal modules. The signal conditioning module is replaced according to the type of detector actually used, including the signal conditioning module of the counter tube type detector, the signal conditioning module of the fission ionization chamber type detector and the signal conditioning module of the boron coated ionization chamber type detector.

[0020] Figure 3 The circuit schematic diagram of the signal conditioning module of the counter tube type detector is given. The module is mainly composed of 5 parts, namely, high voltage generation filter circuit, integral amplifier / secondary amplifier / tertiary amplifier, signal conditioning circuit, DAC circuit and ADC circuit, as follows:

[0021] The high voltage generating and filtering circuit is mainly used to generate high voltage and filter interference signals in the high voltage power supply, and the high voltage is provided to the detector after filtering.

[0022] The high-voltage power supply module of the counter tube is composed of an externally purchased high-voltage module (0V~1500V) and the corresponding high-voltage control, high-voltage sampling, and high-voltage regulation circuits. The high-voltage module supplies power to a relay, which is controlled by a signal processing module. The signal processing module detects the "source-off range detector high-voltage power supply" signal and the "automatic source-off range detector high-voltage power supply" signal, and after performing a logical "or" operation on them, controls the corresponding high-voltage shutoff relay to operate. When the "source-off range detector high-voltage power supply" signal and the "automatic source-off range detector high-voltage power supply" signal disappear at the same time, the corresponding relay is controlled to restore the high-voltage module power supply.

[0023] The integral amplifier / secondary amplifier / tertiary amplifier is a three-stage amplifier used to amplify the weak pulse signal from the boron-coated proportional counter tube.

[0024] The signal conditioning circuit mainly identifies, filters, shapes and drives the amplified signal to output voltage pulses of different frequencies with a pulse width less than 1us and an amplitude greater than 1V.

[0025] The DAC circuit controls the high voltage module and the discrimination level generating circuit to output corresponding voltages according to the high voltage setting value and the discrimination threshold setting value provided by the signal processing module.

[0026] The ADC circuit samples the high voltage division, the discrimination level, and the ±12V voltage, and transmits them to the signal processing module for calculation.

[0027] Figure 4 The circuit schematic diagram of the signal conditioning module of the fission ionization chamber detector is given. The module is mainly composed of 7 parts, namely, high voltage generation filter circuit, integral amplifier / secondary amplifier / tertiary amplifier, signal conditioning circuit, MSV filter circuit, MSV processing circuit, DAC circuit and ADC circuit, as follows:

[0028] The high voltage generating and filtering circuit is mainly used to generate high voltage and filter interference signals in the high voltage power supply, and the high voltage is provided to the detector after filtering.

[0029] The high-voltage power supply module of the fission ionization chamber is composed of an externally purchased high-voltage module (0V~1500V) and corresponding high-voltage control, high-voltage sampling, and high-voltage regulation circuits. The high-voltage module supplies power to a relay, which is controlled by a signal processing module.

[0030] The integral amplifier / secondary amplifier / tertiary amplifier is a three-stage amplifier used to amplify the weak pulse signal from the fission ionization chamber detector.

[0031] The signal conditioning circuit mainly identifies, filters, shapes and drives the amplified signal to output voltage pulses of different frequencies with a pulse width less than 1us and an amplitude greater than 1V.

[0032] The DAC circuit controls the high voltage module and the discrimination level generating circuit to output corresponding voltages according to the high voltage setting value and the discrimination threshold setting value provided by the signal processing module.

[0033] The MSV filter circuit is a bandpass filter, which processes the stacked pulse signal to extract the effective pulse and sends it to the MSV processing module.

[0034] The MSV processing module converts the filtered stack pulses into mean square voltage, and transmits it to the signal processing module after ADC sampling.

[0035] The ADC circuit samples the high voltage division, the discrimination level, and the ±12V voltage, and transmits them to the signal processing module for calculation.

[0036] Figure 5 The circuit schematic diagram of the signal conditioning module of the boron-coated ionization chamber detector is given. The module is mainly composed of five parts, namely, high voltage generation filter circuit, current IV conversion circuit, signal conditioning circuit, DAC circuit and ADC circuit, as follows:

[0037] The high voltage generating and filtering circuit is mainly used to generate high voltage and filter interference signals in the high voltage power supply, and the high voltage is provided to the detector after filtering.

[0038] The high-voltage power supply module is composed of an externally purchased high-voltage module (0V~1500V) and corresponding high-voltage control, high-voltage sampling, and high-voltage regulation circuits. The high-voltage module supplies power to a relay, which is controlled by a signal processing module.

[0039] The current IV conversion circuit is used to amplify the weak current signal from the boron-coated ionization chamber and perform IV conversion.

[0040] The signal conditioning circuit mainly performs filtering processing on the voltage value after IV conversion.

[0041] The DAC circuit controls the high voltage module to output a corresponding voltage according to the high voltage setting value given by the signal processing module.

[0042] The ADC circuit samples the filtered IV voltage value, the high voltage divided voltage, and the ±12V voltage, and transmits them to the signal processing module for calculation.

[0043] Figure 6The circuit schematic diagram of the signal processing module is given. The signal processing module is based on a TIARM processor RM48L952. All functions except data display (including pulse counting, data processing, indicator light control, relay output control, RS232 communication, 4-20mA output control, etc.) are controlled and processed by the processor. The main frequency of RM48L952 can reach 220MHz, and the internal RAM capacity is 256K.

[0044] The main functions of the ARM processor chip peripherals are as follows:

[0045] 1) The internal UART1 is connected to the test interface module RS232 transceiver (non-isolated type) through the baseboard for device parameter setting and reading;

[0046] 2) The internal ADC is used to monitor the digital +5V power supply voltage of the low-voltage power module;

[0047] 3) The internal SPI1 is connected to the signal conditioning module ADC (for high voltage, ±12V, and discrimination threshold monitoring) and DAC (for adjusting the high voltage output value and the discrimination threshold output value) through the baseboard;

[0048] 4) The internal SPI3 is connected to the analog I / O module DAC through the baseboard to control the 4-20mA analog output;

[0049] 5) Internal SPI5 is connected to non-volatile memory for storing device parameters;

[0050] 6) The internal Edge module is used to collect the pulse count output by the signal conditioning module;

[0051] 7) The internal ADC module is used to collect the MSV voltage output of the preamplifier;

[0052] 8) Internal GIO is used to control the switch input and output of the switch I / O module, the high-voltage switch of the signal conditioning module, the indicator light of the status indication module, etc.;

[0053] 9) The internal CAN module is connected to the CAN transceiver of the information display module through the baseboard and is used to send measurement data to the information display module.

[0054] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0055] The above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multifunctional nuclear measurement signal processing device, characterized in that: The signal processing device performs digital processing on the analog signals output by the nuclear measurement counting tube detector, the fission ionization chamber detector and the boron-coated ionization chamber detector, and displays the processed signals; the signal processing device includes three signal conditioning modules, which are respectively used for signal conditioning of three types of nuclear measurement detectors, and the weak signals output by them are shielded through three coaxial cables and connectors and enter the corresponding channels for amplification, filtering, gain adjustment, and signal conditioning and then isolated output; the signal processing device also includes a signal processing module, which uses a high-speed ADC and a counter to sample and count the conditioned signals to form digital signals.

2. The multifunctional nuclear measurement signal processing device according to claim 1, characterized in that: The signal processing device comprises a base plate, a test interface module, a signal processing module, an information display module, a status indication module, a low-voltage power supply module, an AC IN module, a communication I / O module, a switch quantity I / O module, an analog quantity I / O module, and a signal conditioning module, wherein the test interface module, the signal processing module, the information display module, the status indication module, and the low-voltage power supply module are installed at the front of the base plate through a 96-pin connector, and the AC IN module, the communication module, the switch quantity module, the analog quantity I / O module, and the signal conditioning module are installed at the rear of the base plate through a 96-pin connector. The signal conditioning module is replaced according to the type of detector actually used, and comprises a counter tube type detector signal conditioning module, a fission ionization chamber type detector signal conditioning module, and a boron-coated ionization chamber type detector signal conditioning module.

3. The multifunctional nuclear measurement signal processing device according to claim 2, characterized in that: The counter tube type detector signal conditioning module is composed of five parts, namely, high voltage generation filter circuit, integral amplifier / secondary amplifier / tertiary amplifier, signal conditioning circuit, DAC circuit and ADC circuit, as follows: The high voltage generating and filtering circuit is used to generate high voltage and filter interference signals in the high voltage power supply, and the high voltage is provided to the detector after filtering; The counter tube high-voltage power supply module is composed of a high-voltage module and corresponding high-voltage control, high-voltage sampling, and high-voltage regulation circuits. The high-voltage module is powered by a relay connected to the relay, which is controlled by a signal processing module. The signal processing module detects the "source-off range detector high-voltage power supply" signal and the "automatic source-off range detector high-voltage power supply" signal, and after performing a logical "or" operation on them, controls the corresponding high-voltage shutoff relay to act. When the "source-off range detector high-voltage power supply" signal and the "automatic source-off range detector high-voltage power supply" signal disappear at the same time, controls the corresponding relay to restore the high-voltage module power supply; The integral amplifier / secondary amplifier / tertiary amplifier is a three-stage amplifier, which is used to amplify the weak pulse signal from the boron-coated proportional counter tube; The signal conditioning circuit is used to identify, filter, shape and drive the amplified signal to output voltage pulses of different frequencies with a pulse width less than 1us and an amplitude greater than 1V; The DAC circuit controls the high voltage module and the discrimination level generating circuit to output corresponding voltages according to the high voltage setting value and the discrimination threshold setting value given by the signal processing module; The ADC circuit samples the high voltage division, the discrimination level, and the ±12V voltage, and transmits them to the signal processing module for calculation.

4. The multifunctional nuclear measurement signal processing device according to claim 2, characterized in that: The fission ionization chamber detector signal conditioning module is composed of 7 parts, namely, high voltage generation filter circuit, integral amplifier / secondary amplifier / tertiary amplifier, signal conditioning circuit, MSV filter circuit, MSV processing circuit, DAC circuit and ADC circuit, as follows: The high voltage generating and filtering circuit is used to generate high voltage and filter interference signals in the high voltage power supply, and the high voltage is provided to the detector after filtering; The high-voltage power supply module of the fission ionization chamber is composed of a high-voltage module and corresponding high-voltage control, high-voltage sampling, and high-voltage regulation circuits. The high-voltage module supplies power to a relay, which is controlled by a signal processing module. The integral amplifier / secondary amplifier / tertiary amplifier is a three-stage amplifier, which is used to amplify the weak pulse signal from the fission ionization chamber detector; The signal conditioning circuit is used to identify, filter, shape and drive the amplified signal to output voltage pulses of different frequencies with a pulse width less than 1us and an amplitude greater than 1V; The DAC circuit controls the high voltage module and the discrimination level generating circuit to output corresponding voltages according to the high voltage setting value and the discrimination threshold setting value given by the signal processing module; The MSV filter circuit is a bandpass filter, which processes the stacked pulse signal to extract the effective pulse and sends it to the MSV processing module; The MSV processing module converts the filtered stacked pulses into mean square voltage, and transmits it to the signal processing module after ADC sampling; The ADC circuit samples the high voltage division, the discrimination level, and the ±12V voltage, and transmits them to the signal processing module for calculation.

5. The multifunctional nuclear measurement signal processing device according to claim 2, characterized in that: The signal conditioning module of the boron-coated ionization chamber detector consists of five parts, namely, a high voltage generation filter circuit, a current IV conversion circuit, a signal conditioning circuit, a DAC circuit and an ADC circuit, as follows: The high voltage generating and filtering circuit is used to generate high voltage and filter interference signals in the high voltage power supply, and the high voltage is provided to the detector after filtering; The high-voltage power supply module is composed of a high-voltage module and corresponding high-voltage control, high-voltage sampling, and high-voltage regulation circuits. The high-voltage module supplies power to a relay, which is controlled by a signal processing module. The current IV conversion circuit is used to amplify the weak current signal from the boron-coated ionization chamber and perform IV conversion; The signal conditioning circuit is used to filter the voltage value after IV conversion; The DAC circuit controls the high voltage module to output a corresponding voltage according to the high voltage setting value given by the signal processing module; The ADC circuit samples the filtered IV voltage value, the high voltage divided voltage, and the ±12V voltage, and transmits them to the signal processing module for calculation.

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