CN112711061A

CN112711061A - Monitoring system and monitoring method for ray source

Info

Publication number: CN112711061A
Application number: CN202011293486.4A
Authority: CN
Inventors: 汤晓斌; 边明鑫; 许志恒; 龚频; 刘云鹏
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2020-11-18
Filing date: 2020-11-18
Publication date: 2021-04-27
Anticipated expiration: 2040-11-18
Also published as: CN112711061B

Abstract

The application provides a monitoring system and a monitoring method for a ray source. The monitoring system comprises a vertical flat plate, a plurality of energy conversion units, a plurality of sensors and a processor, wherein the vertical flat plate is opposite to the ray source and is fixedly arranged; the plurality of energy conversion units are arranged on the vertical flat plate and used for receiving rays of the ray source at respective positions and converting the rays into first electric signals; each sensor is separately connected with the transduction unit and used for reading a first electric signal of the transduction unit and converting the first electric signal into a second electric signal; the processor is used for collecting second electric signals output by the plurality of sensors and establishing a relation curve of the second electric signals and the position of the energy conversion unit.

Description

Monitoring system and monitoring method for ray source

Technical Field

The present application relates to the field of sensor monitoring, and in particular, to a monitoring system and a monitoring method for a radiation source.

Background

In recent years, irradiation processing and irradiation degradation technologies are continuously updated, and due to the fact that gamma sources such as Co-60, Cs-137 and the like have high preparation activity and strong ray penetration capacity, the gamma sources are widely applied to the related fields of pesticide degradation, food disinfection, medicine disinfection and the like. The irradiation of the goods is usually performed in a closed irradiation chamber made of concrete, and when the supporting facilities are repaired or replaced, a gamma source is required to be sunk in a water well in the irradiation chamber to shield gamma rays generated by the water well. Therefore, the position and integrity of the gamma source need to be accurately monitored, and if workers mistakenly enter the irradiation chamber under the condition that a lifting system of the gamma source fails or the gamma source is damaged and falls into the irradiation chamber, the workers can suffer huge irradiation dose and threaten life safety.

In order to protect the safety of workers, a camera is usually installed on the well wall, and the position and the integrity of a gamma source are monitored by means of shooting through Cerenkov light generated by the gamma source in water. However, due to the limited brightness produced by cerenkov light in water, it is often difficult for a camera to image the details of the gamma source. In addition, the irradiation dose received by the camera increases with the increase of the service time of the camera, so that the glass of the camera becomes dark due to the color center effect, the imaging effect of the camera also becomes poor due to the irradiation dose received by the camera main body, and the working state of the gamma source is easily judged by mistake. In addition, the gamma source cannot be monitored when the power line of the camera fails, such as breakage or poor contact. In addition, the cameras are expensive and fragile, and cause great working difficulty for workers in the installation and decommissioning disassembly process.

Disclosure of Invention

The embodiment of the application provides a monitoring system for a ray source, which comprises a vertical flat plate, a plurality of energy conversion units, a plurality of sensors and a processor, wherein the vertical flat plate is fixedly arranged and is opposite to the ray source; the plurality of energy conversion units are arranged on the vertical flat plate and used for receiving rays from the ray source at respective positions and converting the rays into first electric signals; each sensor is separately connected with the transduction unit and used for reading a first electric signal of the transduction unit and converting the first electric signal into a second electric signal; the processor is used for collecting second electric signals output by the plurality of sensors and establishing a relation curve of the second electric signals and the position of the energy conversion unit.

According to some embodiments, the monitoring system further includes an early warning module, configured to read the relationship curve output by the processor, and issue a failure alarm when a waveform change of the relationship curve and a standard relationship curve exceeds a first threshold, and issue a displacement alarm when the waveform change of the relationship curve and the standard relationship curve exceeds a second threshold, where the standard relationship curve is a relationship curve obtained when the source frame of the radiation source is at a standard position.

According to some embodiments, the ray source comprises P ray source rod groups, each ray source rod group comprises a row of ray source rods, the transduction units are arranged into P transduction unit groups, each transduction unit group comprises a row of transduction units, wherein the width of each transduction unit group is larger than or equal to that of the corresponding row of ray source rod group, the width of each transduction unit is smaller than or equal to that of the corresponding source rod, the gap between the transduction units is smaller than the minimum gap between the source rods, and P is a natural number.

According to some embodiments, the width of the transduction unit group is greater than or equal to the width of a source frame of the ray source, and the central line of each transduction unit group is aligned with the central line of the corresponding ray source rod group.

According to some embodiments, the sensor comprises a power sensor or a current sensor or a voltage sensor, and the transduction unit comprises a PN junction battery.

According to some embodiments, the source of radiation comprises at least one of a gamma ray source, an X ray source, or an electron accelerator.

An embodiment of the present application further provides a monitoring method for a monitoring system of a radiation source, which includes: collecting second electric signals output by the plurality of sensors by using the processor, and establishing a relation curve between the second electric signals and the positions of the energy conversion units, wherein the second electric signals are converted by reading first electric signals of the energy conversion units by the plurality of sensors, and the first electric signals are converted by respectively receiving rays from the ray source at the respective positions by the plurality of energy conversion units; and determining the information of the ray source according to the relation curve.

According to some embodiments, the monitoring method further comprises: sending out a fault alarm when the waveform change of the relation curve and the standard relation curve exceeds a first threshold value; and sending a displacement alarm when the waveform change of the relation curve and the standard relation curve exceeds a second threshold value.

According to some embodiments, the determining the information of the radiation source according to the relationship curve includes: determining the position of a source rod of the ray source according to the peak position value of the relation curve; determining a vacancy of the ray source without a source rod according to a trough bit value of the relation curve; determining the activity of a source rod of the ray source according to the peak value of the relation curve; and determining the position and integrity information of a source rod of the ray source and the position change of a source frame of the ray source according to the characteristics and the change of the relation curve waveform.

According to some embodiments, the determining the position and integrity information of the source rod of the radiation source and the position change of the source frame of the radiation source according to the characteristics and the change of the relation curve waveform comprises: determining integrity information of source rods of the ray source according to the positions of all the source rods of the ray source reflected by the relation curve; determining the position change of a source frame of the ray source according to the overall movement of the relation curve; and determining the position mutation of the source rod of the radiation source according to the local mutation of the relation curve.

The technical scheme that this application provided, the output signal of the transducer unit that usable data processor created along with the relation curve of position realizes the monitoring to the source frame operating condition and the integrality of ray source, and the reliability is high, need not to maintain, has avoided prior art moreover because the camera ages and causes the erroneous judgement to the source frame operating condition.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that these drawings only show some examples of the application and that other embodiments can be obtained by those skilled in the art without inventive step.

FIG. 1 provides a schematic view of a monitoring system for a radiation source according to an embodiment of the present application.

Fig. 2 provides a schematic view of a source rod set of a radiation source according to an embodiment of the application.

FIG. 3 provides a schematic view of a monitoring system for a radiation source according to another embodiment of the present application.

FIG. 4 provides a partial schematic view of a monitoring system for a radiation source according to an embodiment of the present application.

Fig. 5 provides a schematic structural diagram of a vertical plate according to an embodiment of the present application.

Fig. 6 provides a schematic diagram of a monitoring system for a radiation source according to still another embodiment of the present application.

Fig. 7 provides a schematic flow chart of a monitoring method for a radiation source according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be understood that the terms "first", "second", etc. in the claims, description, and drawings of the present application are used for distinguishing between different objects and not for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this application, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The monitoring system 100 for a radiation source includes a vertical plate 110, a plurality of transducing units 120, a plurality of sensors 130, and a processor 140.

Optionally, the radiation source includes at least one of a gamma ray source, an X ray source, or an electron accelerator, but is not limited thereto.

In the irradiation processing process, if the source rod 210 falls from the source rack into the irradiation chamber or the source rack is not parked in a designated area due to the failure of the lifting system, the irradiation damage to the workers entering the irradiation chamber will be caused, and therefore, the integrity and the position of the source rack need to be determined before the workers enter the irradiation chamber. Therefore, finding a monitoring system with high sensitivity, high precision, high reliability, low error rate, long service life and low cost for the gamma source is a big problem restricting the efficient operation of modern irradiation facilities.

The vertical plate 110 is fixed and faces the radiation source. A plurality of transducer elements 120 are disposed on the vertical plate 110 for receiving radiation at respective locations and converting the radiation into first electrical signals. Each sensor 130 is connected to the transducer unit 120 for reading a first electrical signal of the transducer unit 120 and converting the first electrical signal into a second electrical signal. The processor 140 is configured to collect the second electrical signals output by the plurality of sensors 130 and to establish a relationship between the second electrical signals and the position of the transducer unit 120.

The source comprises P source bar sets, each including an array of source bars 210, as shown in fig. 2. In fig. 2, P is 4, there are 4 ray source bar groups in total, the black column is the source bar 210, the number of the ray source bars included in each ray source bar group may be the same or different, and the activity of the ray emitted by each ray source bar 210 may be the same or different.

The transducing units are arranged into P transducing unit groups, each transducing unit group comprises a row of transducing units, wherein the width of each transducing unit group is larger than or equal to that of the corresponding row of ray source rod groups, and P is a natural number, as shown in figure 2.

Alternatively, to obtain a more accurate relationship, the width of the transducer elements 120 is less than or equal to the width of the corresponding source rods 210, and the spacing between the transducer elements 120 is less than the minimum spacing between the source rods 210, as shown in FIG. 2.

The width of the transduction unit group is larger than or equal to that of the source frame of the ray source, and the central line of each transduction unit group is horizontally aligned with the central line of the corresponding ray source rod group, as shown in fig. 2.

Alternatively, the transducer unit 120 may be a PN junction battery, as shown in fig. 3. The number of rows of PN junction cells 120 and the number of PN junction cells in each row may be set according to actual needs for obtaining an accurate relationship curve. As shown in fig. 4, only three rows of PN junction cells 120 are shown, with P ═ 3. However, since the number of rows of source rods in the source frame is not fixed, the PN junction cells 120 with the same number of rows can be arranged to monitor the source rods 210 in the corresponding row. In addition, although only three PN junction batteries 120 are shown in each row in fig. 1, hundreds, or even thousands of PN junction batteries 120 may be provided in each row due to the large number of source racks.

Further, it will be understood by those skilled in the art that each PN junction cell 120 may be made of a material having greater radiation stability in order to extend the service life of the system.

Each sensor 130 may read the output first electric signals from the plurality of PN junction batteries 120, respectively, and display the actual output value of the PN junction battery 120. In the present embodiment, the number of the sensors 130 is the same as the number of the PN junction batteries 120, and is in one-to-one correspondence with the PN junction batteries, that is, as shown in fig. 4, one sensor 130 is corresponding to each PN junction battery 120 for reading the output first electrical signal of the corresponding PN junction battery 120. Those skilled in the art will appreciate that suitable sensors can be selected as the sensor 130 in the present embodiment according to actual situations. The sensor 130 includes a power sensor, a current sensor, or a voltage sensor, but is not limited thereto. In particular, according to some embodiments, the plurality of sensors may be replaced by a multi-channel sensor to simplify the system, but not limited thereto.

According to some embodiments, the vertical plate 110 having the plurality of PN junction batteries 120 fixed on the surface thereof is fixed at the bottom of the well for a long time, and the vertical plate 110 faces the source rack when the source rack is parked at the bottom of the well. The riser 110 includes a top deck 111 and a bottom bracket 112. The PN junction battery 120 is loaded in the groove 113 on the surface of the top plate 111. The bottom bracket 112 is connected with the top plate 111 and supports the top plate 111 to stably park at the bottom of the well so as to ensure that the PN junction battery 120 statically receives the rays at the position. For example, the top plate 111 may be a metal plate with grooves engraved on the surface thereof to ensure that the PN junction cell 120 is fixed on the surface of the top plate 111 for a long period of time, as shown in fig. 5.

Therefore, the monitoring of the working state and the integrity of the radiation source frame can be realized by utilizing the change relation curve of the output signal of the PN junction battery 120 created by the processor 140 along with the position of the PN junction battery 120, the reliability is high, the maintenance is not needed, and the misjudgment of the position of the radiation source frame caused by the aging of the camera is avoided.

In addition, since the sensor 130 adopted in the present embodiment is placed in the control room, the processor 140 can be placed in the control room, and the distance between the sensor 130 and the processor 140 is shortened, so as to avoid the failure of the monitoring system caused by the connection problem between the two.

FIG. 6 provides a schematic view of a monitoring system for a radiation source according to another embodiment of the present application.

The monitoring system 100 for a radiation source includes a vertical plate 110, a plurality of transducer units 120, a plurality of sensors 130, a processor 140, and an early warning module 150.

On the basis of the embodiment shown in fig. 1, the early warning module 150 may read the relationship curve output by the processor 140, and issue a failure alarm when the waveform variation of the relationship curve and the standard relationship curve exceeds a first threshold, and issue a shift alarm when the waveform variation of the relationship curve and the standard relationship curve exceeds a second threshold. Wherein the standard relation curve is a relation curve obtained when a source frame of the ray source is at a standard position. And when the monitored waveform of the relation curve is suddenly changed compared with the waveform of the standard relation curve, a fault alarm is sent out when the waveform of the relation curve exceeds a first threshold value. When the monitored waveform change of the relation curve and the standard relation curve exceeds a second threshold value, the position of the radiation source frame is wrong, and therefore an alarm is given. It should be noted that the calibration curve will have a certain decay, and the calibration update is required periodically.

After the relationship curve output by the processor 140 is subjected to graph screening by the early warning module 150, whether the integrity and the position of the source frame have faults or not can be judged according to the change of the relationship curve.

As shown in fig. 6, the long-distance wires 160 are respectively used for connecting the PN junction battery 120 and the sensor 130, and respectively transmit the output signal of the PN junction battery 120 to the corresponding sensor 130.

As will be appreciated by those skilled in the art, the early warning module 150 is configured to determine whether a change in the relationship curve created by the processor 140 exceeds a threshold to alert workers to the integrity and location of the source rack as to whether a fault has occurred. Specifically, the position of the source bar 210 of the radiation source can be determined according to the peak value of the relationship curve, and the position change of the source bar 210 of the radiation source can be determined according to the characteristics and the change of the waveform of the relationship curve. For example, if a position of the waveform of the steady relationship curve has a sudden change and exceeds the first threshold, it may be that the position of the source rod 210 has a large change and needs to be maintained, and the early warning module 150 will issue a fault alarm.

In addition, since the PN junction battery 120 is located downhole and the sensor 130 is located in the control room, the long distance wire 160 should be selected to have a lower resistance to reduce the loss of the signal generated by the PN junction battery 120 during transmission.

According to some embodiments, the monitoring system 100 for the radiation source further comprises a short distance wire (not shown in the figures). The short-distance wires are used to connect the plurality of sensors 130 and the processor 140, and the processor 140 and the early warning module 150, so that the readings of the sensors 130 are transmitted to the processor 140, and the relationship curve created by the processor 140 can be transmitted to the early warning module 150.

At S10, the processor 140 collects the second electrical signals output by the plurality of sensors 130 and establishes a plot of the second electrical signals versus the position of the transducer element 120.

The second electrical signal is converted from a first electrical signal of the transducer unit 120 read by the plurality of sensors 130, and the first electrical signal is converted from a first electrical signal of the transducer unit 120 receiving the radiation existing at each position.

The rays existing at the respective positions are received by the PN junction cells 120 distributed in a plurality of rows, respectively. The output first electric signal of the PN junction battery 120 is read using the sensor 130 and converted into a second electric signal. The first electrical signal is a current or voltage signal into which the PN junction battery 120 converts the radiation. The second electrical signal is a current value or a voltage value signal converted by the sensor 130 reading the first electrical signal, and may be an amplitude signal, but not limited thereto.

The processor collects the second electrical signals of the plurality of sensors 130 and creates a plot of the second electrical signals versus the position of the PN junction battery 120 to which the corresponding sensor 130 is connected.

In S20, the information of the source is determined based on the relationship curve.

Specifically, the position of the source bar 210 of the radiation source is determined according to the peak position value of the relationship curve, the vacancy of the radiation source without the source bar 210 is determined according to the valley position value of the relationship curve, the activity of the source bar 210 of the radiation source is determined according to the peak and peak value of the relationship curve, and the position and integrity information of the source bar 210 of the radiation source and the position change of the source frame of the radiation source are determined according to the characteristic and the change of the waveform of the relationship curve.

Wherein, according to the change of the waveform of the relationship curve, the position change and the integrity information of the source bar 210 of the ray source and the position change of the source frame of the ray source are determined, including the following cases.

According to the positions of all source bars 210 of the source of radiation represented by the relation curve, the integrity information of the source bars 210 of the source of radiation is determined.

And determining the position change of the source frame of the ray source according to the overall movement of the relation curve. The curve changes when the source holder position changes, i.e., is lifted out of the well or lowered into the well. The lifting and lowering actions of the source frame are integral actions, the whole source rod group moves, so that the curve changes integrally, if the source frame has a plurality of groups of source rods 210, the curves for the plurality of groups of source rods 210 change, and the characteristics of integral change and simultaneous change of the plurality of groups of curves can be determined for the lifting of the source frame.

And determining the position mutation of the source rod 210 of the radiation source according to the local mutation of the relation curve. For example, if the source holder is broken, i.e., the active rod 210 is dropped, a portion of the points on the curve will change, the output of the transducer unit near the location facing the dropped source rod 210 will decrease, and one peak of the curve will become a valley or disappear, but points at other locations on the curve will not change, and there will be no effect on other sets of curves. That is, only the peak at a specific position on the curve of the source rod 210 is changed, and the other positions are not changed, but are only changed locally, and it is this local change that the source rod 210 can be detected to fall, and the position of the source rod 210 falling can also be known.

Optionally, a fault alarm is issued when the relationship curve changes from the standard relationship curve by more than a preset first threshold value. That is, for example, if a sudden change occurs at a certain position of the waveform of the stationary relationship curve, it may be that the position of the source rod 210 has changed greatly, and an early warning is required to prompt maintenance. The setting of the specific second threshold is determined according to actual conditions.

Optionally, a displacement alarm is issued when the waveform change of the relation curve and a standard relation curve exceeds a second threshold value, wherein the standard relation curve is the relation curve obtained when the source frame of the ray source is at a standard position. When the monitored waveform change of the relation curve and the standard relation curve exceeds a second threshold value, the position of the radiation source frame is wrong, and therefore an alarm is given. It should be noted that the calibration curve will have a certain decay, and the calibration update is required periodically. The setting of the specific second threshold is determined according to actual conditions.

It should be noted that the above-mentioned embodiments described with reference to the drawings are only intended to illustrate the present application and not to limit the scope of the present application, and those skilled in the art should understand that modifications or equivalent substitutions made on the present application without departing from the spirit and scope of the present application should be included in the scope of the present application. Furthermore, unless the context indicates otherwise, words that appear in the singular include the plural and vice versa. Additionally, all or a portion of any embodiment may be utilized with all or a portion of any other embodiment, unless stated otherwise.

Claims

1. A monitoring system for a radiation source, comprising:

the vertical flat plate is fixedly arranged and is opposite to the ray source;

the plurality of energy conversion units are arranged on the vertical flat plate and used for receiving rays from the ray source at respective positions and converting the rays into first electric signals;

a plurality of sensors, each sensor being individually connected to the transducing unit for reading a first electrical signal of the transducing unit and converting the first electrical signal into a second electrical signal;

and the processor is used for collecting second electric signals output by the plurality of sensors and establishing a relation curve of the second electric signals and the position of the energy conversion unit.

2. The monitoring system of claim 1, further comprising:

and the early warning module is used for reading the relation curve output by the processor, sending out a fault alarm when the waveform change of the relation curve and a standard relation curve exceeds a first threshold value, and sending out a displacement alarm when the waveform change of the relation curve and the standard relation curve exceeds a second threshold value, wherein the standard relation curve is obtained when the source frame of the ray source is at a standard position.

3. The monitoring system of claim 1, wherein the radiation source comprises P radiation source bar groups, each radiation source bar group comprises a row of radiation source bars, the transduction units are arranged into P transduction unit groups, each transduction unit group comprises a row of transduction units, wherein the width of each transduction unit group is greater than or equal to that of the corresponding row of radiation source bar groups, the width of each transduction unit is less than or equal to that of the corresponding source bar, the gap between the transduction units is less than the minimum gap between the source bars, and P is a natural number.

4. The monitoring system of claim 3, wherein the width of the group of transducing units is equal to or greater than the width of a source gantry of the source, and a centerline of each group of transducing units is aligned with a centerline of the corresponding group of source rods.

5. The monitoring system of claim 1, wherein the sensor comprises a power sensor or a current sensor or a voltage sensor and the transducing unit comprises a PN junction battery.

6. The monitoring system of claim 1, wherein the radiation source comprises at least one of a gamma ray source, an X-ray source, or an electron accelerator.

7. A monitoring method of a monitoring system for a radiation source as claimed in any one of claims 1 to 6, comprising:

collecting second electric signals output by the plurality of sensors by using the processor, and establishing a relation curve between the second electric signals and the positions of the energy conversion units, wherein the second electric signals are converted by reading first electric signals of the energy conversion units by the plurality of sensors, and the first electric signals are converted by respectively receiving rays from the ray source at the respective positions by the plurality of energy conversion units;

and determining the information of the ray source according to the relation curve.

8. The monitoring method of claim 7, further comprising:

sending out a fault alarm when the waveform change of the relation curve and the standard relation curve exceeds a first threshold value;

and sending a displacement alarm when the waveform change of the relation curve and the standard relation curve exceeds a second threshold value.

9. The monitoring method according to claim 7, wherein said determining information of said radiation source according to said relation curve comprises:

determining the position of a source rod of the ray source according to the peak position value of the relation curve;

determining a vacancy of the ray source without a source rod according to a trough bit value of the relation curve;

determining the activity of a source rod of the ray source according to the peak value of the relation curve;

and determining the position and integrity information of a source rod of the ray source and the position change of a source frame of the ray source according to the characteristics and the change of the relation curve waveform.

10. The monitoring method of claim 9, wherein said determining position and integrity information of a source rod of said source and position change of a source frame of said source from characteristics and changes of said relationship curve waveform comprises:

determining integrity information of source rods of the ray source according to the positions of all the source rods of the ray source reflected by the relation curve;

determining the position change of a source frame of the ray source according to the overall movement of the relation curve;

and determining the position mutation of the source rod of the radiation source according to the local mutation of the relation curve.