WO2013174141A1

WO2013174141A1 - Gain stabilizing device for detector system and control method thereof

Info

Publication number: WO2013174141A1
Application number: PCT/CN2012/088081
Authority: WO
Inventors: 陈琳; 阮明; 苗高峰; 吕君; 吴涛
Original assignee: 同方威视技术股份有限公司
Priority date: 2012-05-25
Filing date: 2012-12-31
Publication date: 2013-11-28
Also published as: CN103424768A

Abstract

A gain stabilizing device for a detector system and gain stabilization control method, the device comprising a light source (31); a detector unit (4) for receiving the light coming from the light source (31), and converting a light signal into an electrical signal; an amplification circuit (6) for gain-amplifying the electrical signal coming from the detector unit (4); a data acquisition module (7) coupled with the amplification circuit (6) and used for acquiring the electrical signal having been gain-amplified by the amplification circuit (6), and outputting a detection output value corresponding to the light intensity of the light source (31); and a control unit for comparing the detection output value outputted by the data acquisition module (7) with a predetermined ray energy calibration value, and adjusting the variable gain of the amplification circuit (6) based on the comparison result, so as to enable the detection output value to be consistent with the calibration value.

Description

A gain stabilization device for a detector system and a control method therefor. The present application claims the application No. 201210167077. filed on May 25, 2012, entitled "A Gain Stabilizer for a Detector System" The priority of the Chinese Patent Application, the entire disclosure of which is incorporated herein by reference. Technical field

The present invention relates to a gain stabilizing device for a detector system, and more particularly to a gain stabilizing device for a flicker detector system. The invention is useful for performance stabilization and self-test of radioactive material ray detection systems using scintillation detectors. Additionally, the invention relates to a method of controlling a gain stabilization device for a detector system. Background technique

The detector is an important component of the radioactive material detection system. The scintillation detector has the advantages of high detection efficiency, high measurement sensitivity and wide spectrum response, so the scintillation detector system is widely used in the field of radioactive material detection.

Since scintillator crystals, photomultiplier tubes, and electronic circuits are susceptible to changes in ambient temperature and humidity and self-aging, the performance of the scintillation detector system changes, so such devices must be regularly subjected to gain correction and calibration. At present, the common method is to regularly send the equipment to the authoritative department, and use the standard radioactive source to correct and scale, which brings a lot of inconvenience to the actual use.

The ray has been proposed to use the illuminating characteristics of the LED light source to simulate the illuminating process of the ray in the crystal, and to test the physical properties of the scintillator. However, the similar technology at this stage does not have self-stabilizing and self-calibrating for the detector system. Features.

Accordingly, it is desirable to provide a gain stabilization apparatus for a detector system and a control method thereof that utilizes an illumination source for self-test, self-stabilization, self-calibration of a scintillation detector system, particularly gains to a detector system, and The self-stabilizing control device and method for the luminous intensity of the light source. Summary of the invention

In view of this, the object of the present invention is to solve at least one of the above problems and deficiencies existing in the prior art. Face.

Accordingly, it is an object of the present invention to provide a gain stabilizing apparatus for a detector system, comprising: a stabilizing unit front end module comprising: a light source; and a photometric element for measuring light from the light source Luminous intensity, convert it into light intensity data and output it;

a stabilizing unit control module that receives light intensity data output by the photometric element, compares it with light intensity calibration data of the light source, and adjusts an illumination intensity of the light source based on the comparison result, So that the light intensity data is consistent with the light intensity calibration data;

a detector unit for receiving light from the light source and converting the optical signal into an electrical signal representing the optical signal;

An amplifying circuit for performing gain amplification on an electrical signal from the detector unit;

a data acquisition module, coupled to the amplifying circuit, configured to collect an amplified electrical signal amplified by the gain of the amplifying circuit, and output a detected output value corresponding to the light intensity of the light source;

a control unit, configured to compare a detected output value output by the data acquisition module with a predetermined ray energy calibration value, and adjust a variable gain of the amplification circuit based on the comparison result, so that the detecting The output value is consistent with the nominal value. .

In the above technical solution, the control unit includes a host computer, configured to read a detected output value of the data acquisition module, and calculate a difference between the detected output value output by the data acquisition module and the calibration value. Wherein - when the difference is greater than zero, reducing the gain of the amplifying circuit; when the difference is less than zero, increasing the gain of the amplifying circuit.

In the above technical solution, the stabilizing unit control module calculates a difference between the light intensity data output by the photometric element and the light intensity calibration data of the light source, wherein: when the difference is greater than zero, the The luminous intensity of the light source; when the difference is less than zero, the luminous intensity of the light source is increased.

In the above technical solution, the stabilizing unit front end module further includes: a temperature measuring component for measuring a temperature of the photometric component; the stabilizing unit control module is responsive to a temperature change of the temperature measuring component, The luminous intensity of the light source is adjusted such that the luminous intensity of the light source is independent of the temperature of the photometric element.

Specifically, the detector unit includes: a scintillator detector; and a photomultiplier tube connected to the scintillator detector.

In the above technical solution, the stabilizing unit front end module is coupled to the surface of the scintillator detector and is optically coupled to the scintillator detector.

Specifically, the upper computer is an industrial computer, and the control unit is respectively connected to the stability unit through the communication port, and is enlarged. The circuit communicates with the data acquisition module.

Specifically, the scintillator detector is for detecting gamma rays or neutrons; and the light source is an LED light source. According to another aspect of the present invention, there is provided a control method for gain stabilization of a detector system, comprising the steps of: controlling a illuminating source to emit light at a calibrated illuminating intensity; and driving a detector unit to receive light from the light source, And converting the optical signal into an electrical signal representing the optical signal; performing gain amplification on the electrical signal from the detector unit through the amplifying circuit; collecting the amplified electrical signal amplified by the gain of the amplifying circuit through the data collecting module, and outputting the corresponding a detection output value of the light source intensity; determining a parameter variation of the detector system by comparing the detected output value output by the data acquisition module with a predetermined ray energy calibration value, and based on the parameter The amount of variation adjusts the variable gain of the amplifying circuit such that the detected output value coincides with the nominal value.

In the above technical solution, the step of adjusting the variable gain of the amplifying circuit comprises: reading a detected output value of the data collecting module, and calculating a detected output value output by the data collecting module and the a difference between the calibration values, wherein: when the difference is greater than zero, the gain of the amplifying circuit is decreased; when the difference is less than zero, the gain of the amplifying circuit is increased.

Further, a method for controlling gain stabilization of a detector system is characterized by further comprising the steps of: measuring a luminous intensity from the light source by a photometric element, converting it into light intensity data and outputting; and receiving by the photometric element Outputting the light intensity data, comparing it with the light intensity calibration data of the light source, and adjusting the light emission intensity of the light source based on the comparison result, so that the light intensity data and the light intensity are calibrated The data is consistent.

In the above technical solution, the adjusting step includes: calculating a difference between the light intensity data output by the photometric element and the light intensity calibration data of the light source, wherein: when the difference is greater than zero, reducing the The luminous intensity of the light source; when the difference is less than zero, the luminous intensity of the light source is increased.

In a preferred mode, the control method further includes the steps of: measuring a temperature of the photometric element by a temperature measuring element, and outputting data of a temperature of the photometric element to the stable unit control module; and responding The illumination intensity of the light source is adjusted to a temperature change of the temperature measuring element such that the illumination intensity of the light source is independent of the temperature of the photometric element.

Further, when the difference between the light intensity data output by the photometric element and the light intensity calibration data of the light source and the detection output value output by the data acquisition module and the predetermined ray energy calibration value are both zero At the end, the adjustment of the luminous intensity of the light source and the gain of the detector system is ended.

The above non-specific embodiments of the present invention have at least the advantages and effects of one or more of the following aspects - The present invention is directed to the above-described changes in the stability of the scintillation detector system that are susceptible to changes in ambient temperature and humidity and self-aging. In a preferred embodiment, it provides a stabilizing unit, and the unit is provided by a stabilizing unit front end module. And a stable unit control module; the stability unit front end module may include a light emitting device as a light source, an ambient temperature sensor, a light intensity detecting device and a light reducing sheet, the front unit of the stabilizing unit is mounted close to the surface of the detector, and is detected with the scintillator The light unit is coupled; the stable unit control module controls the luminous intensity and time of the light emitting device in the front end module, and is a control module with automatic correction; cooperates with an amplifying circuit, such as a high precision digital gain amplifying circuit, and a host computer, such as an industrial computer , workstation, can automatically complete the gain correction and calibration of the scintillation detector system.

The invention utilizes the characteristics of the spectrum of the constant pulse light emitted by the illumination source to match the emission, conduction and absorption spectra of the scintillator, and simulates and controls the luminescence intensity of the illuminating source to simulate the luminescence characteristics and the luminescence amount of the ray in the scintillation body, combined with digital control. A gain amplifying circuit that achieves self-stabilization and self-test of the entire detector system without the use of a standard source.

Compared with the prior art, the invention has good stability and real-time performance in realizing timing and non-timed self-checking and self-calibration of the scintillation detector system; and has reasonable design, good compatibility, wide adaptability and no need to be equipped. Complex equipment, no need for radioactive sources, low operating costs, safe operation and so on. Thus, the present invention is widely applicable to the technical field of development and manufacture of various instruments and equipment for detecting the dose, energy spectrum, and count rate of radioactive material rays by using a scintillation detector system. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic structural view of a gain stabilizing apparatus for a detector system according to an embodiment of the present invention.

Figure 2 is a logic diagram showing the self-stabilizing operation of the gain stabilization device for the detector system of Figure 1;

3 is a flow diagram of a control method for gain stabilization of a detector system in accordance with an embodiment of the present invention. detailed description

The technical solutions of the present invention will be further specifically described below by way of embodiments and in conjunction with FIGS. 1-3. In the specification, the same or similar reference numerals indicate the same or similar parts. The following description of the embodiments of the present invention is intended to explain the present general inventive concept, and should not be construed A limitation.

1 shows a schematic structural view of a gain stabilization device for a detector system in accordance with a preferred embodiment of the present invention. As shown in FIG. 1, the upper computer 1 is included; the stable unit control module 2; the stable unit front end module _{3; the} scintillation detector 4; the photomultiplier tube 5 coupled to the scintillator detector; the amplifying circuit 6; and the data collecting module 7.

In a gain stabilization device for a detector system according to the invention, it comprises: a light source 31; a detector unit 4, 5, such as a Nal or Lil detector, for receiving light from the source 31 And converting the optical signal into an electrical signal representing the optical signal; an amplifying circuit 6 for gain amplifying the electrical signal from the detector unit 4, 5; a data acquisition module 7, and the amplifying circuit 6 Phase coupling, for collecting an amplified electrical signal amplified by the amplification circuit 6 and outputting a detection output value corresponding to the light source intensity; a host computer 1 as a control unit for using the data acquisition module The output detected value of 7 is compared with a predetermined ray energy calibration value, and the variable gain of the amplifying circuit 6 is adjusted based on the comparison result such that the detected output value coincides with the calibration value.

In one embodiment, the stabilizing unit front end module 3 is composed of a light source 31, a photometric element 32, a temperature measuring element 33, and a light reducing sheet 34. In the present invention, the light source may employ an LED light source, but the present invention is not limited thereto, and for example, it may be a light source that can be used to simulate a suitable spectrum of a light-emitting process in a crystal, such as a light source of a blue spectrum. The photometric element 32 is for measuring the intensity of illumination from the source, converting it to intensity data and outputting it, which may be any intensity detecting device, such as a photomultiplier tube, suitable for detecting the above spectrum. The temperature measuring element 33 can be any type of thermometer that measures the ambient temperature, thereby indirectly obtaining the temperature of the photometric element 32. The upper computer 1 can be an industrial computer, and communicates with the stable unit control module 2, the amplifying circuit 6 and the data collecting module 7 through the communication port.

The stabilizing unit front end module 3 is in close contact with the surface of the scintillation detector 4 to optically couple the light source 31 to the scintillator detector 4. In the above-described embodiments of the present invention, an external pulsed constant light source may be employed, which may be a controlled light source or an uncontrolled light source, whereby the light source 31 couples the scintillation detector to simulate the illuminating process of the ray in the scintillator crystal. When the light source 31 emits light, a portion of the photons enter the scintillation detector 4, for example, through a dimmer or beam splitter 34, and are then passed to a photomultiplier tube 5 coupled to the scintillation detector 4. The electric signal output from the photomultiplier tube 5 is input to an amplifying circuit 6, for example, a digital gain amplifying circuit. In the amplifying circuit 6, the electric signal is proportionally amplified, and then collected by the data collecting module 7. By using the above light source, a process in which a ray is detected by a detector is simulated.

On the other hand, when the light source 31 emits light, a part of the photons are converted into a light intensity data signal by the photometric element 32, for example, the light intensity detecting means, and transmitted to the stabilizing unit control module 2. In the stability unit control module 2, through the real When the difference ERR0R1 between the intensity data and the calibration value of the luminous intensity of the light source 31 is calculated, the luminous intensity is corrected in real time to ensure the stability of the luminous intensity. In the above embodiment, the calibration value of the luminous intensity of the light source 31 is calibrated by a standard ray source such that the calibrated value of the illuminating intensity of the light source coincides with the illuminating intensity value of the standard ray source.

In the above embodiment, the signal output from the photomultiplier tube 5 is passed through the amplifying circuit 6 and the data acquisition module 7 to the host computer 1 as a control unit. For example, the industrial computer and the workstation are collected by the host computer 1 to the data acquisition module 7. The actual data detected by the characterization detector 4 should be compared to the normal ray energy calibration value of the normal detector system. In this embodiment, the normal detector system should be calibrated by a standard ray source to be calibrated by a standard ray source, and calibrated by a standard ray source. The standard ray energy value of the detector system is a predetermined ray energy calibration value. When the light source 31 is adjusted to coincide with the illuminance intensity value of the standard ray source, it can be estimated that the difference between the actual data detected by the data acquisition module 7 and the characterization of the ray energy calibration value that the normal detector system should obtain. The value is caused by the amount of change in the parameters of the detector system. By automatically adjusting the gain of the amplifying circuit 6, the entire system can be restored to a normal state.

Referring to FIG. 2, the host computer 1 is configured to read the detection output value of the data acquisition module 7, and calculate a difference ERR0R2 between the detection output value output by the data acquisition module 7 and the calibration value, where: When the difference is greater than zero, the gain of the amplifying circuit 6 is lowered; when the difference is less than zero, the increase of the amplifying circuit 6 is increased.

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In a preferred technical solution, the gain stabilization device of the detector system further includes: a stability unit control module

2, receiving light intensity data output by the light metering element 32, comparing it with light intensity calibration data of the light source, and adjusting the light intensity of the light source 31 based on the comparison result, The light intensity data is made to coincide with the light intensity calibration data. Referring to FIG. 2, the stabilization unit control module 2 calculates a difference ERR0R1 between the light intensity data output by the light metering element 32 and the light intensity calibration data of the light source, wherein: when the difference is greater than zero, the light source is lowered. The luminous intensity of 31; when the difference is less than zero, the luminous intensity of the light source 31 is increased.

In the above technical solution, the temperature measuring element 33 is used to measure the temperature of the photometric element 33, that is, the external ambient temperature, and output data of the temperature of the photometric element 32 to the stable unit control module 2 The stabilization unit control module 2 adjusts the illumination intensity of the light source 31 in response to a temperature change of the temperature measurement element 33 such that the illumination intensity of the light source 31 is independent of the temperature of the photometric element 32.

A control method of a gain stabilization device for a detector system according to an embodiment of the present invention will now be described with reference to FIGS. 2 and 3. As shown in FIG. 3, a control method for gain stabilization of a detector system according to the present invention includes the steps of: controlling the illumination source 31 to emit light with a calibrated illumination intensity by the host computer 1 (S1) _; driving the detector unit 4, 5 receiving light from the light source 31, and converting the optical signal into representing the optical signal Electrical signal (S2); gain amplification of the electrical signal from the detector unit 4, 5 by the amplifying circuit 6 (S3); acquisition of the amplified electrical signal amplified by the amplification circuit 6 by the data acquisition module 7, and output Corresponding to the detected output value of the light source 31 (S4); determining the parameter variation of the detector system by comparing the detected output value output by the data acquisition module with a predetermined ray energy calibration value, And adjusting the variable gain of the amplifying circuit based on the parameter variation amount so that the detected output value coincides with the calibration value (S5).

As shown in Fig. 2, in a preferred manner, the self-stabilization of the illumination intensity of the light source 32 can also be achieved by the stabilization unit control module 2. Specifically, the intensity of the light emitted from the light source 31 is measured by the photometric element 32, converted into light intensity data and output; and the light intensity data output by the photometric element 32 is received and combined with the light source The light intensity calibration data of 31 is compared, and the light emission intensity of the light source 31 is adjusted based on the comparison result to make the light intensity data coincide with the light intensity calibration data.

The specific operation flow can be obtained as follows: After the stabilization unit control module 2 receives the correction instruction issued by the upper computer 1, the control stability unit front end module 3 illuminates the illumination source 31 and feeds the light intensity to the stabilization unit control module 2, The stabilization unit control module 2 calculates the value of the difference ERR0R1, changes the illumination parameter value, and controls the illumination intensity until the difference ERR0R1 meets the requirements. The upper machine 1 reads the data acquisition module 7 and compares the signal value with the predetermined ray energy reference value to obtain the difference ERR0R2, and corrects the amplification circuit 6 according to the specific situation, until the requirements are met, the illumination source is turned off, and an operation is completed. Referring to FIG. 2, the difference between the light intensity data output by the photometric element 32 and the light intensity calibration data of the light source 31 and the difference between the detected output value output by the data acquisition module 7 and a predetermined ray energy calibration value When the values are all zero, the adjustment of the luminous intensity of the light source 31 and the gain of the detector system is ended, thereby exiting the self-test state.

The application of the detector system of the present invention to a radioactive material security system, such as a gamma ray monitoring system, will now be briefly described with reference to FIG. In one embodiment, the radioactive material security system includes the self-stabilizing detector system of the present invention, and the workflow thereof is as follows: 1. The upper computer 1 issues an instruction, and the system enters a self-test state; 2. The radioactive material security inspection system passes the detector. The unit 4, 5 measures the environmental background dose, energy spectrum, and count; 3. controls the illumination source 31 to emit light, and automatically adjusts the illumination intensity according to the illumination parameter, so that the light intensity data output by the photometry element 32 and the light of the light source 31 are The strong calibration data is consistent; 4. Detect the luminous intensity of the illumination source 31, subtract the environmental background dose, energy spectrum, and count; 5. Calculate the variation of the detector system parameters; 6. Adjust the gain of the amplification circuit 6 to make the The detection output value outputted by the data acquisition module 7 is consistent with the predetermined ray energy calibration value; 7. The radioactive material security inspection system exits the self-test state.

By adopting the above technical solution, the invention realizes the timing and non-time self-test of the scintillation detector system, and self-engraving It has good stability and real-time performance. At the same time, it has reasonable design, good compatibility, wide adaptability, no need to be equipped with complicated equipment, no need for radioactive source, low operating cost and safe operation. The invention is widely applicable to the technical fields of developing and manufacturing various instruments and equipment for detecting the dose, energy spectrum and counting rate of radioactive material rays by using a scintillation detector system.

While some embodiments of the present general inventive concept are shown and described, it will be understood by those of ordinary skill in the art that the present invention may be modified without departing from the principles and spirit of the present general inventive concept. The scope is defined by the claims and their equivalents.

Claims

Rights request

A gain stabilization device for a detector system, comprising:

a stabilizing unit front end module, comprising: a light source; and a photometric element for measuring an intensity of illumination from the light source, converting it into light intensity data and outputting;

a control unit, configured to compare a detected output value output by the data acquisition module with a predetermined ray energy calibration value, and adjust a variable gain of the amplification circuit based on the comparison result, so that the detecting The output value is consistent with the nominal value.

2. The gain stabilization device for a detector system according to claim 1, wherein: said control unit comprises a host computer for reading a detected output value of said data acquisition module, and calculating The difference between the detected output value output by the data acquisition module and the calibration value, wherein:

When the difference is greater than zero, the gain of the amplifying circuit is decreased; when the difference is less than zero, the gain of the amplifying circuit is increased.

3. The gain stabilization device for a detector system according to claim 1, wherein: said stabilization unit control module calculates light intensity data output by said light metering element and light intensity calibration data of said light source Difference, where:

When the difference is greater than zero, the illumination intensity of the light source is decreased; when the difference is less than zero, the illumination intensity of the light source is increased.

The gain stabilization device for a detector system according to any one of claims 1 to 3, characterized in that - the stabilization unit front end module further comprises: a temperature measuring element for measuring the photometry a temperature of the component, and outputting data of the temperature of the photometric element to the stabilizing unit control module;

The stabilizing unit control module adjusts the illuminating intensity of the light source in response to a temperature change of the temperature measuring element such that the illuminating intensity of the light source is independent of the temperature of the photometric element.

The gain stabilization device for a detector system according to any one of claims 1 to 3, characterized in that the detector unit comprises - a scintillator detector; and is connected to the scintillator detector Photomultiplier tube.

6. The gain stabilizing device for a detector system according to claim 5, wherein said stabilizing unit front end module is coupled to a surface of said scintillator detector and optically coupled to said scintillator detector .

The gain stabilization device for a detector system according to claim 2 or 3, wherein: the upper computer is an industrial computer, and the communication unit is respectively connected to a stability unit control module, an amplification circuit, and a data acquisition module. communication.

8. The gain stabilization device for a detector system according to claim 7, wherein: the scintillator detector is for detecting gamma rays or neutrons; and the light source is an LED light source.

9. A control method for gain stabilization of a detector system, comprising the steps of: controlling a illuminating source to illuminate at a calibrated illuminating intensity;

Driving the detector unit to receive light from the source and converting the optical signal into an electrical signal representative of the optical signal;

Amplifying the electrical signal from the detector unit by an amplification circuit;

Acquiring an amplified electrical signal amplified by the gain of the amplifying circuit through a data acquisition module, and outputting a detected output value corresponding to the light intensity of the light source;

Determining a parameter variation amount of the detector system by comparing a detected output value output by the data acquisition module with a predetermined ray energy calibration value, and variable the amplification circuit based on the parameter variation amount The gain is adjusted such that the detected output value coincides with the nominal value.

10. The control method for gain stabilization of a detector system according to claim 9, wherein said step of adjusting said variable gain of said amplifying circuit comprises: reading a detection output of said data acquisition module a value, and calculating a difference between the detected output value output by the data acquisition module and the calibration value, wherein - when the difference is greater than zero, reducing a gain of the amplifying circuit; when the difference is less than zero , increasing the gain of the amplifying circuit.

11. The control method for gain stabilization of a detector system according to claim 10, further comprising the steps of:

Measuring a luminous intensity from the light source by a photometric element, converting it into light intensity data and outputting; and receiving light intensity data output by the photometric element, and performing the light intensity calibration data with the light source Comparing, and adjusting the luminous intensity of the light source based on the comparison result, so that the light intensity data is consistent with the light intensity calibration data.

12. The control method for gain stabilization of a detector system according to claim 11, wherein the adjusting step comprises:

Calculating a difference between the light intensity data output by the light metering element and the light intensity calibration data of the light source, wherein: when the difference is greater than zero, reducing the light intensity of the light source; when the difference is less than zero At the time, the luminous intensity of the light source is increased.

The control method for gain stabilization of a detector system according to any one of claims 9 to 12, further comprising the step of: measuring a temperature of the photometric element by the temperature measuring element;

The illumination intensity of the light source is adjusted in response to a temperature change of the temperature measuring element such that the illumination intensity of the light source is independent of the temperature of the photometric element.

14. The control method for gain stabilization of a detector system according to claim 13, wherein: a difference between light intensity data output by said photometric element and light intensity calibration data of said light source, and said Number When the difference between the detected output value output by the acquisition module and the predetermined ray energy calibration value is zero, the adjustment of the illumination intensity of the light source and the gain of the detector system is ended.