CN108279431B

CN108279431B - Portable radiation dosimeter, dose monitoring equipment and segmented processing method

Info

Publication number: CN108279431B
Application number: CN201810412050.9A
Authority: CN
Inventors: 查钢强
Original assignee: Xi'an Aikesi Optoelectronic Technology Co ltd
Current assignee: Xi'an Aikesi Optoelectronic Technology Co ltd
Priority date: 2018-05-02
Filing date: 2018-05-02
Publication date: 2023-06-06
Anticipated expiration: 2038-05-02
Also published as: CN108279431A

Abstract

The invention relates to a portable radiation dosimeter, dose monitoring equipment and a segmentation processing method, and belongs to the technical field of radioactive detection instruments. The portable radiation dosimeter comprises: a CZT detector, a signal processing system, a processor and a shield made of metallic material. The CZT detector, the signal processing system and the processor are sequentially coupled, and the CZT detector, the signal processing system and the processor are all arranged in the shielding cover. Compared with the prior art, the signal processing system is adopted to amplify, shape and screen the electric signal output by the CZT detector and then output the amplified, shaped and screened electric signal to the processor for preprocessing, so that the amplitude, pulse width and the like of the output signal can be changed, the dose linearity of the portable radiation dosimeter and the dose monitoring equipment is improved, and the portable radiation dosimeter still has higher detection efficiency when the working voltage of the CZT detector is reduced to the safe voltage of a human body.

Description

Portable radiation dosimeter, dose monitoring equipment and segmented processing method

Technical Field

The invention belongs to the technical field of radioactive detection instruments, and particularly relates to a portable radiation dosimeter, dose monitoring equipment and a sectional processing method.

Background

People face special personal safety, environmental safety and other problems while widely utilizing nuclear energy and nuclear technology. Thus, in nuclear technology applications, ensuring the safety of the public and the surrounding ecological environment requires real-time monitoring of the surrounding radiation dose by an environmental-level dose rate meter.

The main probe parts of the dosimeters in the market are mainly a G-M tube and a silicon diode, and the application of the two types of personal dosimeters is greatly limited due to the fact that the G-M tube has larger dead time and lower detection efficiency on gamma rays, and meanwhile, the silicon diode has poorer angular response and lower detection efficiency on gamma rays. The dosimeter of the novel CZT semiconductor detector can make up the defects of low detection efficiency and long dead time of the G-M tube and the silicon diode. Therefore, the dose rate meter based on the CZT semiconductor detector is an ideal X and gamma dose rate meter.

The CZT semiconductor detector needs a higher working voltage to achieve a higher detection efficiency, however, for a personal dosimeter for home use, the working voltage of the detector needs to be reduced to a safe voltage of a human body based on the characteristics of safety, reliability and portability. However, as the working voltage of the detector decreases, the detection efficiency also decreases correspondingly, so how to reduce the working voltage to the safety voltage of the human body under the condition of ensuring that the detector has higher detection efficiency is a focus of industry attention.

Disclosure of Invention

In view of the foregoing, it is an object of the present invention to provide a portable radiation dosimeter, a dose monitoring device and a segmented processing method, which effectively improve the above-mentioned problems.

Embodiments of the present invention are implemented as follows:

in one aspect, an embodiment of the present invention provides a portable radiation dosimeter comprising: a CZT detector, a signal processing system, a processor and a shield made of metallic material. The CZT detector, the signal processing system and the processor are coupled, the CZT detector, the signal processing system and the processor are arranged in the shielding cover, the signal processing system is used for amplifying, shaping and screening electric signals output by the CZT detector and outputting the electric signals to the processor, and the processor is used for preprocessing the electric signals output by the signal processing system according to a preset standard.

In a preferred embodiment of the present invention, the signal processing system includes: the CZT detector, the pre-amplifying module, the preprocessing module and the comparison module are sequentially coupled; the pre-amplification module is used for amplifying the received electric signals output by the CZT detector and outputting the amplified electric signals to the preprocessing module; the preprocessing module is used for shaping and amplifying the electric signals output by the pre-amplifying module and outputting the electric signals to the comparison module; the comparison module is used for outputting signals meeting preset standards in the electric signals output by the preprocessing module to the processor for processing.

In a preferred embodiment of the present invention, the pre-amplification module comprises: the MOS tube is grounded at the source electrode, the drain electrode of the MOS tube is respectively coupled with the first input end and the second input end of the first amplifier, the grid electrode of the MOS tube is respectively coupled with the CZT detector and the output end of the first amplifier, and the output end of the first amplifier is further coupled with the preprocessing module.

In a preferred embodiment of the present invention, the preprocessing module includes: a differentiating circuit and an amplifying circuit, the differentiating circuit being coupled to the pre-amplifying module and the amplifying circuit, respectively, the amplifying circuit being coupled to the comparing module; the differentiating circuit is used for shaping the electric signal output by the pre-amplifying module and outputting the shaped electric signal to the amplifying circuit; the amplifying circuit is used for amplifying the electric signal output by the differentiating circuit and outputting the electric signal to the comparing module.

In a preferred embodiment of the present invention, the differentiating circuit is a CR differentiating circuit.

In a preferred embodiment of the present invention, the amplifying circuit includes: the first input end of the second amplifier is coupled with the differential circuit, the second input end of the second amplifier is coupled with the output end of the second amplifier, the output end of the second amplifier is coupled with the comparison module, and the second input end of the second amplifier is also grounded.

In a preferred embodiment of the present invention, the comparing module includes: and the first input end of the comparator is coupled with the reference voltage, the second input end of the comparator is coupled with the preprocessing module, and the output end of the comparator is coupled with the processor.

The embodiment of the invention also provides a dose monitoring device, which comprises: the portable radiation dosimeter comprises a control terminal and the portable radiation dosimeter, wherein the control terminal is coupled with a processor in the portable radiation dosimeter.

On the other hand, the embodiment of the invention also provides a segmentation processing method, which is applied to the portable radiation dosimeter, and comprises the following steps: response data to X and gamma rays are obtained; judging whether the response data is smaller than a first preset value, if so, obtaining the dose rate according to a first preset calibration coefficient and the obtained response data, and if the response data is larger than or equal to the first preset value, obtaining the dose rate according to a second preset calibration coefficient and the obtained response data.

Compared with the prior art, the portable radiation dosimeter, the dose monitoring device and the segmentation processing method provided by the embodiment of the invention have the advantages that the CZT detector has higher atomic number, so that the thickness of the detection material can reach the centimeter level, the excellent detection efficiency is ensured, and in addition, the portable radiation dosimeter has the characteristics of high energy resolution, high sensitivity, small volume, light weight and the like. In addition, the signal processing system is adopted to amplify, shape and screen the electric signal output by the CZT detector and then output the electric signal to the processor for processing, so that the amplitude, pulse width and the like of the output signal can be changed, the dose linearity of the portable radiation dosimeter and the dose monitoring equipment is improved, and the portable radiation dosimeter still has higher detection efficiency when the working voltage of the CZT detector is reduced to the safe voltage of a human body. The shielding case not only can protect the CZT detector, the signal processing system and the processor which are arranged in the shielding case from being damaged, but also can prolong the service life; and the CZT detector, the signal processing system and the processor can be prevented from being interfered by external electromagnetic signals, so that the accuracy of the radiation dose rate is improved. The present invention further provides: good detection efficiency, high sensitivity, small volume, strong anti-interference capability and the like.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the embodiments of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings. Like reference numerals refer to like parts throughout the several views of the drawings. The drawings are not intended to be drawn to scale, with emphasis instead being placed upon illustrating the principles of the invention.

Fig. 1 shows a schematic structural diagram of a portable radiation dosimeter according to an embodiment of the invention.

Fig. 2 is a block diagram of a signal processing system in fig. 1 according to an embodiment of the present invention.

Fig. 3 shows a schematic circuit diagram of the pre-amplifier module of fig. 2 provided by an embodiment of the present invention.

Fig. 4 shows a schematic circuit diagram of the preprocessing module in fig. 2 according to an embodiment of the present invention.

Fig. 5 shows a schematic circuit diagram of the comparison module in fig. 2 according to an embodiment of the present invention.

Fig. 6 shows a comparison of the radiation dose rate before and after the segmentation process.

Fig. 7 shows a block diagram of a dose monitoring device according to an embodiment of the present invention.

Fig. 8 shows a method flowchart of a segmentation processing method according to an embodiment of the present invention.

Icon: 10-portable radiation dosimeter; 11-shielding case; 13-CZT detector; 15-a signal processing system; 151-a pre-amplification module; 152-a preprocessing module; 1521-differentiating circuit; 1522-amplifying circuit; 153-comparison module; 17-a processor; 20-dose monitoring device; 21-control terminal.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," "coupled" and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

An embodiment of the present invention provides a portable radiation dosimeter 10, as shown in fig. 1. The portable radiation dosimeter 10 comprises: a CZT detector 13, a signal processing system 15, a processor 17 and a shield 11.

The shielding 11 is used for protecting the CZT detector 13, the signal processing system 15 and the processor 17, i.e. the CZT detector 13, the signal processing system 15 and the processor 17 are all arranged in the shielding 11. The shape of the shield 11 may be various, for example, a rectangular parallelepiped, a cylindrical body, an elliptic cylindrical body, or the like. The shield 11 is made of a metallic material, for example, iron, aluminum, copper, etc., to protect the CZT detector 13, the signal processing system 15 and the processor 17 from external electromagnetic signals to improve accuracy of the radiation dose rate. In this embodiment, the shield 11 is preferably provided with a communication port (not shown) that is coupled to the processor 17. The communication port is used for communicating with external equipment so as to facilitate outputting detected signals to the external equipment and receiving control instructions of the external equipment, thereby facilitating the processing of updating, maintenance and the like of the portable radiation dosimeter 10. The communication port may be a USB port, an RS232 port, or an RJ45 port.

The CZT detector 13 is a detector made of CdZnTe ternary compound semiconductor material, and since cadmium zinc telluride (CdZnTe) has a high atomic number, the thickness of the detection material can reach the order of centimeters, thereby ensuring excellent detection efficiency. The CZT detector 13 is a novel nuclear radiation detection component, outputs pulse signals, does not need refrigeration, has the characteristics of high energy resolution, high sensitivity, small volume, light weight and the like, and is mainly used for energy spectrum measurement of X and gamma rays. The CZT detector 13 may be a CZT detector 13 commonly used in the market at present, for example, the CZT detector 13 may be of DT-P01 type. Wherein, the length, width and thickness dimensions of the CZT detector 13 are preferably not greater than (i.e. not greater than) 20mmX10mm, which includes various dimensions, for example, 20mmX8mm, 20mmX10mm, 10mmX20mmX5mm, etc., in this embodiment, it is further preferred that the length, width and thickness dimensions of the CZT detector 13 are 20mmX5mm.

The signal processing system 15 is configured to amplify, filter, shape, screen, and analog-to-digital convert the electrical signal output by the CZT detector 13, so as to improve the dose linearity of the portable radiation dosimeter 10. In this embodiment, as shown in fig. 2, the signal processing system 15 preferably includes: a pre-amplification module 151, a pre-processing module 152 and a comparison module 153.

The pre-amplifying module 151 is coupled to the CZT detector 13 and the preprocessing module 152, respectively, and is configured to amplify the received electrical signal output by the CZT detector 13 and output the amplified electrical signal to the preprocessing module 152. In this embodiment, as shown in fig. 3, preferably, the pre-amplifying module 151 includes: a MOS transistor Q1 and a first amplifier U1. The source electrode of the MOS transistor Q1 is grounded, and further preferably, the source electrode of the MOS transistor Q1 is grounded through a first resistor R1. The drain of the MOS transistor Q1 is respectively coupled with the first input end and the second input end of the first amplifier U1, in addition, the drain of the MOS transistor Q1 is also connected with a +5V power supply through a second resistor R2, and the drain of the MOS transistor Q1 is also connected with the +5V power supply through a third resistor R3. The grid electrode of the MOS tube Q1 is respectively coupled with the CZT detector 13 and the output end of the first amplifier U1, and preferably, the grid electrode of the MOS tube Q1 is connected with the CZT detector 13 through a first capacitor C1; the grid electrode of the MOS tube Q1 is further coupled with the output end of the first amplifier U1 through a second capacitor C2, and the grid electrode of the MOS tube Q1 is further coupled with the output end of the first amplifier U1 through a fourth resistor R4. The output of the first amplifier U1 is also coupled to the preprocessing module 152. The second input of the first amplifier U1 is furthermore connected to ground via a fifth resistor R5. The first power end of the first amplifier U1 is connected with a +5V power supply, and the second power end is grounded.

The MOS transistor Q1 is an input stage of an operational amplifier, and is used for improving input impedance and amplifying a signal output by the CZT detector 13. The amplitude and pulse width can be changed by adjusting the C2 and R4 through the second capacitor C2 as a feedback capacitor and the fourth resistor R4 as a feedback resistor.

Wherein, preferably, the first input terminal of the first amplifier U1 may be a non-inverting input terminal, and the second input terminal of the first amplifier U1 may be an inverting input terminal. The first power supply end of the first amplifier U1 is an in-phase power supply end, and the second power supply end of the first amplifier U1 is an anti-phase power supply end.

The port HV in FIG. 3 is used to connect to an external high voltage power source, which may be as low as 20-100V, for powering the CZT detector 13. Port 1 in fig. 3 is used to connect with the preprocessing module 152.

The preprocessing module 152 is coupled to the pre-amplifying module 151 and the comparing module 153, respectively, and is configured to filter, shape, amplify and output the electrical signal output by the pre-amplifying module 151 to the comparing module 153. In this embodiment, as shown in fig. 4, the preprocessing module 152 preferably includes: a differentiating circuit 1521 and an amplifying circuit 1522.

The differentiating circuit 1521 is coupled to the pre-amplifying module 151 and the amplifying circuit 1522, respectively, and in this embodiment, the differentiating circuit 1521 is preferably a CR differentiating circuit. As shown by the left dashed box in fig. 4, it is further preferable that the differentiating circuit 1521 includes: a third capacitor C3 and a sixth resistor R6. One end of the third capacitor C3 is used to connect with the pre-amplifying module 151, and further, one end of the third capacitor C3 is used to connect with the output end of the first amplifier U1 in the pre-amplifying module 151. The other end of the third capacitor C3 is grounded via a sixth resistor R6, and the other end of the third capacitor C3 is further coupled to the amplifying circuit 1522. The pulse signal output from the pre-amplifier module 151 is converted into a quasi-gaussian signal by the differentiating circuit 1521, and the differentiating circuit 1521 can filter out a noise signal superimposed on the output signal of the CZT detector 13.

The amplifying circuit 1522 is coupled to the differentiating circuit 1521 and the comparing module 153, respectively, and is configured to amplify the signal output from the differentiating circuit 1521 and output the amplified signal to the comparing module 153. In this embodiment, as shown in the right dashed box in fig. 4, the amplifying circuit 1522 preferably includes: and a second amplifier U2. The first input terminal of the second amplifier U2 is coupled to the differentiating circuit 1521, further, the first input terminal of the second amplifier U2 is connected to the other terminal of the third capacitor C3, and the first input terminal of the second amplifier U2 is further grounded via a sixth resistor R6. In addition, the first input terminal of the second amplifier U2 is further grounded via a seventh resistor R7, and the first input terminal of the second amplifier U2 is further connected to a +5v power supply via an eighth resistor R8. The second input of the second amplifier U2 is coupled to its output, and further preferably the second input of the second amplifier U2 is connected to its output via a ninth resistor R9. In addition, the second input terminal of the second amplifier U2 is further grounded, and further preferably, the second input terminal of the second amplifier U2 is further grounded after being connected in series through a tenth resistor R10 and a fourth capacitor C4. The output of the second amplifier U2 is coupled to the comparing module 153, and further, the output of the second amplifier U2 is coupled to the comparing module 153 via an eleventh resistor R11. The first power end of the second amplifier U2 is connected with a +5V power supply, and the second power end is grounded.

Wherein preferably the first input of the second amplifier U2 may be a non-inverting input and the second input of the second amplifier U2 may be an inverting input. The first power supply end of the second amplifier U2 is an in-phase power supply end, and the second power supply end of the second amplifier U2 is an anti-phase power supply end.

Wherein port 2 in fig. 4 is used for connection with port 1 in fig. 3, and port 3 in fig. 4 is used for connection with comparison module 153.

The comparing module 153 is coupled to the preprocessing module 152 and the processor 17, respectively, and is configured to output a signal meeting a preset standard in the electrical signals output by the preprocessing module 152 to the processor 17 for processing. In this embodiment, as shown in fig. 5, the comparing module 153 preferably includes: and a comparator U3. The first input of the comparator U3 is coupled to a reference voltage, and further preferably the first input of the comparator U3 is connected to the reference voltage via a twelfth resistor R12, and furthermore the first input of the comparator U3 is grounded via a thirteenth resistor R13. The second input of the comparator U3 is coupled to the preprocessing module 152, and further preferably, the first input of the comparator U3 is connected to the preprocessing module 152 via a fourteenth resistor R14, and furthermore, the first input of the comparator U3 is grounded via a fifteenth resistor R15. The output of the comparator U3 is coupled to the processor 17, preferably the output of the comparator U3 is coupled to the processor 17 after being connected to a sixteenth resistor R16. The first power end of the comparator U3 is connected with a +5V power supply, and the second power end of the comparator U3 is grounded. The quasi-gaussian signal output by the preprocessing module 152 is filtered by the comparing module 153 to output a square wave signal. The comparison module 153 is further configured to convert the received analog signal into a digital signal for output.

In this embodiment, the comparison module 153 preferably outputs a signal greater than the reference voltage from the electrical signals output by the preprocessing module 152. The predetermined standard is a reference voltage, which may be set according to actual requirements, for example, in this embodiment, the reference voltage is set to +5v.

Wherein preferably the first input of the comparator U3 may be an inverting input and the second input of the comparator U3 may be a non-inverting input. The first power supply end of the comparator U3 is an in-phase power supply end, and the second power supply end of the comparator U3 is an anti-phase power supply end.

Wherein port 4 in fig. 5 is for connection with port 3 in fig. 4, and port 5 in fig. 5 is for connection with processor 17.

The processor 17 is coupled to the signal processing system 15 for preprocessing the electrical signal output by the signal processing system 15 according to a preset standard. The processor 17 is preferably coupled to a comparison module 153 in the signal processing system 15 and further connected to an output of a comparator U3 in the comparison module 153. The processor 17 processes the signals output by the comparison module 153 according to preset criteria to reduce the output bias of the portable radiation dosimeter 10, particularly in low dose rate environments. The preset standard refers to that the manager performs the segment calibration processing on the signal received by the processor 17 according to the preset threshold according to the actual use requirement.

For the sake of more clear explanation of the principle of the preset criteria, the following description will be given by way of example only with respect to the case of two preset thresholds, and the case of the remaining preset thresholds is similar, and is not repeated here. Preferably, when the processor 17 receives the signal output by the comparing module 153, the value of the received signal is determined with the first threshold, and if the value of the received signal is smaller than the first threshold, the dose rate y1 is obtained according to the first preset calibration coefficient and the obtained signal value. If the value of the received signal is greater than or equal to the first threshold value, the dose rate y2 is obtained according to the second preset calibration coefficient and the obtained signal value. The expression is as follows:

wherein a and b are first preset calibration coefficients, c and d are second preset calibration coefficients, y is a dose rate, and X is a value of a signal received by the processor 17, namely response data of the portable radiation dosimeter 10 to X and gamma rays.

As shown in fig. 6, after the signals output from the comparing module 153 are processed in segments according to the preset standard, the output deviation of the portable radiation dosimeter 10 becomes smaller, especially at low dose rates, from the original deviation of 280% to-12%. The deviation data before and after the segment calibration are shown in table 1.

TABLE 1

It is readily apparent from the data in the meter that the signal output by the comparison module 153 is segmented so that the output deviation of the portable radiation dosimeter 10 is small, especially at low dose rates.

Wherein a, b, c, d is obtained by standard radiation field calibration, for example, the portable radiation dosimeter 10 is placed in a standard dose field of a first threshold segment (x < 1000), response data of the portable radiation dosimeter 10 to radiation at a plurality of sets of dose rates is tested to obtain an array (xi, yi), and coefficients a, b are obtained by least squares linear fitting, wherein the expression is as follows: yi=axi+b.

Placing the portable radiation dosimeter 10 in a standard dose field of a second threshold segment (x is larger than or equal to 1000), testing response data of the portable radiation dosimeter 10 to radiation under a plurality of groups of dose rates to obtain an array (xi, yi), and obtaining coefficients c and d by using least square method straight line fitting, wherein the expression is as follows: yi=cxi+d.

In order to make the calibration factor a, b, c, d as accurate as possible, as many sets of response data of the portable radiation dosimeter 10 to radiation at different dose rates should be tested as possible, typically no less than 3 sets.

It should be understood that, in the foregoing, only the case of the preset standard under the two preset thresholds is shown, and it may also include the case of a plurality of preset thresholds, for example, the first preset value is 100, the second threshold is 200, the third preset value is 300, and so on, and therefore, the case of the preset standard under the two preset values shown in the foregoing, and the value of the preset threshold, and so on, are not to be construed as limiting the present invention, regardless of the change of the value of the preset threshold, and how many preset thresholds are set, and so on, as long as they are included in the scope of the present invention in the principle thereof.

The processor 17 may be an integrated circuit chip, and has a signal processing capability. The processor 17 may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processing, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general purpose processor may be a microprocessor or the processor 17 may be any conventional processor 17 or the like. For example, when the processor 17 is an STM32 single-chip microcomputer, a general purpose input/output (General Purpose Input Output, simply referred to as GPIO) port of the single-chip microcomputer is connected to an output end of the comparator U3.

The embodiment of the present invention also provides a dose monitoring device 20 as shown in fig. 7. The dose monitoring device 20 comprises: a control terminal 21 and the portable radiation dosimeter 10 described above, said control terminal 21 being coupled to a processor 17 in said portable radiation dosimeter 10. The control terminal 21 is operable to receive signals transmitted by the processor 17, i.e. the dose rate output by the portable radiation dosimeter 10. In addition, the control terminal 21 may perform data update, program update, etc. on the portable radiation dosimeter 10 in time according to actual use requirements, for example, update preset criteria stored in the processor 17, etc. The control terminal 21 includes, but is not limited to, a computer.

The embodiment of the invention also provides a sectional processing method which is applied to the portable radiation dosimeter 10. As shown in fig. 8, the segmentation processing method includes the steps of: S101-S102.

Step S101: response data to X-rays and gamma-rays are obtained.

The response data may be obtained by a dosimeter, which may be placed in a radiation field of unknown emissivity to obtain response data to X, gamma rays, for example.

Step S102: and judging whether the response data is smaller than a first preset value.

If the response data is smaller than the first preset value, step S103 is executed, and if the response data is not smaller than the first preset value, step S104 is executed.

Step S103: and obtaining the dose rate according to the first preset calibration coefficient and the obtained response data.

Comparing the obtained response data with a first preset value, and if the response data is smaller than the first preset value, obtaining the dose rate according to a first preset calibration coefficient and the obtained response data. Preferably, if the response data is smaller than a first preset value, the dose rate is obtained according to the formula y=ax+b, where y is the dose rate, X is the obtained response data to X and γ rays, and a and b are first preset calibration coefficients.

Step S104: and obtaining the dose rate according to the second preset calibration coefficient and the obtained response data.

And if the response data is larger than or equal to (not smaller than) the first preset value, obtaining the dose rate according to the second preset calibration coefficient and the obtained response data. Preferably, if the response data is not less than the first preset value, that is, the response data is greater than or equal to the first preset value, the dose rate is obtained according to the formula y=cx+d, where y is the dose rate, X is the obtained response data to X and γ rays, and c and d are the second preset calibration coefficients.

The first predetermined calibration coefficients a, b and the second predetermined calibration coefficients c, d are obtained by standard radiation field calibration, and the method of obtaining the same is described in the description of the predetermined standard of the processor 17 and will not be described here.

The first preset value is a value set or divided by a user or a manager according to actual use needs, for example, the first preset value may be set to 1000. It should be understood that the first preset value in the above is only a preferred example for the sake of understanding, and it may be the remaining value, and thus it should not be construed as limiting the present invention. In addition, a plurality of preset thresholds, for example, 500, 1000, 1500, etc. can be set according to actual needs, and the principle is similar.

In summary, the embodiment of the invention provides a portable radiation dosimeter, a dose monitoring device and a segmented processing method. The portable radiation dosimeter comprises: a CZT detector, a signal processing system, a processor, and a shield. Wherein the signal processing system comprises: the device comprises a pre-amplifying module, a preprocessing module and a comparison module. The CZT detector has higher atomic number, so that the thickness of the detection material can reach the centimeter level, thereby ensuring the excellent detection efficiency, and the CZT detector has the characteristics of high energy resolution, high sensitivity, small volume, light weight and the like. In addition, the signal processing system is adopted to amplify, shape, filter and screen the electric signal output by the CZT detector and then output the electric signal to the processor for preprocessing, so that the amplitude, pulse width and the like of the output signal can be changed, and the dose linearity of the portable radiation dosimeter and the dose monitoring equipment can be improved. Further, the pre-amplifying module is used for amplifying the received pulse signals output by the CZT detector and outputting the amplified pulse signals to the preprocessing module; the pulse signal output by the pre-amplification module is converted into a quasi-Gaussian signal to be output after passing through the pre-processing module, and in addition, the pre-processing module can also filter noise signals superposed in the output signals of the CZT detector; the quasi-Gaussian signal output by the preprocessing module is filtered by the comparison module and then square wave signals are output. In addition, the processor is adopted to preprocess the signal output by the received comparison module, so that the portable radiation dosimeter still has higher detection efficiency when the working voltage of the CZT detector is reduced to the safe voltage of a human body, and the output deviation of the portable radiation dosimeter can be effectively reduced, so that the output deviation of the portable radiation dosimeter is reduced, and particularly, the effect is remarkable when the dosage rate is low. The shielding case not only can protect the CZT detector, the signal processing system and the processor which are arranged in the shielding case from being damaged, but also can prolong the service life; and the CZT detector, the signal processing system and the processor can be prevented from being interfered by external electromagnetic signals, so that the accuracy of the radiation dose rate is improved. The present invention further provides: good detection efficiency, high sensitivity, small volume, strong anti-interference capability and the like.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art.

Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A portable radiation dosimeter comprising: the CZT detector, the signal processing system and the processor are all arranged in the shielding case, the signal processing system is used for amplifying, shaping and screening the electric signals output by the CZT detector and outputting the electric signals to the processor, and the processor is used for preprocessing the electric signals output by the signal processing system according to a preset standard;

wherein the signal processing system comprises: the CZT detector, the pre-amplifying module, the preprocessing module, the comparing module and the processor are sequentially coupled;

the pre-amplification module is used for amplifying the received electric signals output by the CZT detector and outputting the amplified electric signals to the preprocessing module;

the preprocessing module is used for shaping and amplifying the electric signals output by the pre-amplifying module and outputting the electric signals to the comparison module;

the comparison module is used for outputting signals meeting preset standards in the electric signals output by the preprocessing module to the processor for processing;

wherein the pre-amplification module comprises: the MOS transistor is grounded at the source electrode, the drain electrode of the MOS transistor is respectively coupled with the first input end and the second input end of the first amplifier, the grid electrode of the MOS transistor is respectively coupled with the CZT detector and the output end of the first amplifier, and the output end of the first amplifier is further coupled with the preprocessing module;

the preprocessing module comprises: a differentiating circuit and an amplifying circuit, the differentiating circuit being coupled to the pre-amplifying module and the amplifying circuit, respectively, the amplifying circuit being coupled to the comparing module;

the differentiating circuit is used for shaping the electric signal output by the pre-amplifying module and outputting the shaped electric signal to the amplifying circuit;

the amplifying circuit is used for amplifying the electric signal output by the differentiating circuit and outputting the electric signal to the comparing module.

2. The portable radiation dosimeter of claim 1, wherein the differentiating circuit is a CR differentiating circuit.

3. The portable radiation dosimeter of claim 1, wherein the amplification circuit comprises: the first input end of the second amplifier is coupled with the differential circuit, the second input end of the second amplifier is coupled with the output end of the second amplifier, the output end of the second amplifier is coupled with the comparison module, and the second input end of the second amplifier is also grounded.

4. The portable radiation dosimeter of claim 1, wherein the comparison module comprises: and the first input end of the comparator is coupled with the reference voltage, the second input end of the comparator is coupled with the preprocessing module, and the output end of the comparator is coupled with the processor.

5. A dose monitoring device, comprising: a control terminal and a portable radiation dosimeter according to any of claims 1-4, the control terminal being coupled to a processor in the portable radiation dosimeter.

6. A segmented processing method for use in a portable radiation dosimeter according to any of claims 1-4, the method comprising:

response data to X and gamma rays are obtained;

judging whether the response data is smaller than a first preset value, if so, obtaining the dose rate according to a first preset calibration coefficient and the obtained response data, and if the response data is larger than or equal to the first preset value, obtaining the dose rate according to a second preset calibration coefficient and the obtained response data.

7. The segmentation process according to claim 6, wherein the step of comparing the obtained response data with a first preset value, obtaining a dose rate according to a first preset calibration coefficient and the obtained response data if the response data is smaller than the first preset value, and obtaining a dose rate according to a second preset calibration coefficient and the obtained response data if the response data is greater than or equal to the first preset value comprises:

comparing the obtained response data with a first preset value, obtaining a dose rate according to a formula y=ax+b if the response data is smaller than the first preset value, and obtaining the dose rate according to a formula y=cx+d if the response data is larger than or equal to the first preset value, wherein y is the dose rate, X is the obtained response data to X and gamma rays, a and b are first preset calibration coefficients, c and d are second preset calibration coefficients, and a, b, c, d can be obtained through standard radiation field calibration.