CN212379578U

CN212379578U - Barrier-free array type rapid positioning system for radioactive source

Info

Publication number: CN212379578U
Application number: CN202020916204.0U
Authority: CN
Inventors: 张志勇; 刘思平; 杨奎; 廉小龙; 李晨
Original assignee: Shanghai Ergonomics Detecting Instrument Co ltd
Current assignee: Shanghai Ergonomics Detecting Instrument Co ltd
Priority date: 2020-05-26
Filing date: 2020-05-26
Publication date: 2021-01-19
Anticipated expiration: 2030-05-26

Abstract

The utility model discloses a quick positioning system of accessible array radiation source, including main detector array, camera, vice detector array and detection area, main detector array installs for seven probe arrays, and the parallel pedestrian's direction of central point position probe, vice detector array are three probe arrays, the perpendicular pedestrian's direction of middle probe, detection area 4 is 4 mx 1.8 m's space, the beneficial effects of the utility model are that: (1) the radiation detection area can reach a plane of 4m multiplied by 4m and is dozens of times larger than the channel type pedestrian detection area; (2) if the radiation of the detected person is normal, the person does not need to stay and directly passes through the device; (3) if the radiation of the detected person exceeds the standard, not only alarm information but also the specific position of the person with the radiation exceeding the standard is given, and the whole process is recorded through a camera and is shot, amplified and displayed to a user. (4) The acquisition signal is 200ms, which is 5 times faster than the existing conventional pedestrian access door in 1 second.

Description

Barrier-free array type rapid positioning system for radioactive source

Technical Field

The utility model relates to a location technical field specifically is a quick positioning system of accessible array radiation source.

Background

As international terrorism rampant and nuclear smuggling and nuclear diffusion are difficult to be restrained, China faces greater and greater danger of nuclear terrorism. The nuclear anti-terrorism is one of three international anti-terrorism items, and the traditional channel type detection method of the radioactive substances of the pedestrians is to set a channel to detect the pedestrians. This kind of detection mode is because the rate of detection is high near apart from the detector, but the narrow detection speed in passageway is slow, and near leading to the fact personnel to pass through inefficiency from the staff, and in case also has certain influence to the staff in the emergence radiation.

Disclosure of Invention

An object of the utility model is to provide a barrier-free array type radiation source quick positioning system to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

a barrier-free array type rapid positioning system for a radioactive source comprises a main detector array, a camera, an auxiliary detector array and a detection area, wherein the main detector array is arranged into a seven-probe array, a probe at the center position is parallel to the direction of a pedestrian and is used for detecting radiation characteristics in a mode of being vertical to the pedestrian, the auxiliary detector array is a three-probe array, a middle probe is vertical to the direction of the pedestrian and is used for detecting the radiation characteristics in the advancing direction of the pedestrian, and the specific position of an overproof radiator is determined by cross combination; the detection area 4 is a space of 4m × 4m × 1.8m, a plane of 4m × 4m is coded, the plane is divided into 16 feature grids of 1m × 1m, the feature grids are divided into 4 heights according to the height of 1.8m, the total detection area is divided into 64 feature grids, radiation features are coded, the radiation features are coded, and the camera is installed above the detection area. The camera detects the radiation characteristics, determines the radiation position according to the codes, and transmits the position information to the camera to snap the personnel with the radiation exceeding the standard.

As a further aspect of the present invention: the main detector array and the auxiliary detector array are both sodium iodide detector arrays with lead shielding, lead is surrounded on the side face of a sodium iodide crystal and extends forwards, radiation response characteristics of lead shielding of a single crystal are calculated by a Monte Carr algorithm, then a model is corrected through a specific experiment, and radiation of a positioning system under various conditions is simulated according to the result of the experimental correction to obtain actual radiation characteristic data.

As a further aspect of the present invention: the thickness of the lead shield is 2cm, and the distance extending forwards is 5 cm.

As a further aspect of the present invention: the probe comprises a shell, a PMT (photomultiplier tube) and a front-end signal amplification circuit, a cylindrical lead shielding layer and a sodium iodide crystal probe, wherein the PMT and the front-end signal amplification circuit are arranged in the shell.

As a further aspect of the present invention: the outer shell cover is made of aluminum-plastic plate light materials, and the thickness of the outer shell cover is 4 mm.

Compared with the prior art, the beneficial effects of the utility model are that: (1) the radiation detection area can reach a plane of 4m multiplied by 4m and is dozens of times larger than the channel type pedestrian detection area; (2) if the radiation of the detected person is normal, the person does not need to stay and directly passes through the device; (3) if the radiation of the detected person exceeds the standard, not only alarm information but also the specific position of the person with the radiation exceeding the standard is given, and the whole process is recorded through a camera and is shot, amplified and displayed to a user. (4) The acquisition signal is 200ms, which is 5 times faster than the existing conventional pedestrian access door in 1 second.

Drawings

FIG. 1 is a schematic view of a barrier-free array type radiation source rapid positioning system

FIG. 2 is a radiation characteristic diagram of a Monte Carlo simulation bare crystal.

Fig. 3 is a graph comparing radiation characteristics after lead shielding.

Fig. 4 is a schematic diagram of a single crystal lead shield.

Fig. 5 is a schematic view of the installation orientation.

In the figure: 1-a main detector array; 2. a camera; 3. a secondary detector array; 4. detecting a region; 5. PMT and front end signal amplifying circuit; 6. a cylindrical lead shielding layer and a 7-sodium iodide crystal probe.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1, embodiment 1: the embodiment of the utility model provides an in, a quick positioning system of accessible array radiation source, include: eight parts including a front 7 sodium iodide main detector array 1, a side 3 sodium iodide auxiliary detector array 3, a sodium iodide nuclide identification probe, a 3He neutron detector, a radiation signal processing circuit board, a camera 2, an equipment housing and an upper computer.

The sodium iodide detector is a 3 inch x 3 inch cylindrical crystal with a lead shield surrounding the outside of the crystal. And (4) leading the lead shielding layer out of the detector for a certain distance, and determining the distance of the lead shielding layer out of the detector finally according to the detection height and the distance. The size of the lead shielding is accurately calculated by a Monte Carlo method and corrected by experiments, so that the simulation effect is close to the actual scene application as far as possible. After a single crystal simulation model is corrected through experiments, an array sodium iodide detector model of the front 7 side 3 is established according to the final application scene of the product.

The final model of the detector array is determined by a Monte Care algorithm through a plurality of experiments. The height of the detectors is 3m, the distance between the front detectors is 50cm, and the distance between the side detectors is 50 cm.

The downward inclination angle and the left and right inclination angles of the detector are obtained through a Monte Carlo algorithm. An optimal model is finally obtained by simulating hundreds of models.

The sodium iodide nuclide identification probe is different from a positioning array sodium iodide probe. Lead shielding is not required to improve nuclide identification efficiency. The position of the probe is arranged below the central positioning probe of the front detector array and is close to the front for a certain distance. The nuclide identification algorithm adopts a characteristic peak nuclide identification method.

The neutron detector is a cylindrical 3He gas detector, and in order to improve the detection efficiency of neutrons, a slowing layer with a certain thickness is wrapped around the detector. The neutron detection does not determine the specific position, once neutron alarm occurs, the alarm level is the highest level, and the detection area is completely displayed in red.

The radiation signal circuit processes the board, which includes signal conversion and collection for all detectors. The radiation acquisition signal is 200ms, and the radiation signal around the detector is uninterruptedly acquired and transmitted to the upper computer for analysis and processing.

The neutron detector adopts signal acquisition with 1s frequency for ensuring the stability of data because of less signals.

The camera carries out real-time video recording on the detection area, and when radiation position information is transmitted to the camera, the camera starts short-time high-definition video recording and captures the license plate for storage. When the alarm is not given, the video is only recorded in a conventional mode and stored according to the day.

The equipment outer cover is made of aluminum-plastic plate light materials, and the thickness of the equipment outer cover is 4 mm. The light weight of the aluminum-plastic plate can reduce the shielding of the shell to radioactive rays to the maximum extent. The aluminum-plastic plate has smooth appearance, completely surrounds the detector and the signal processing circuit board, and has good attractive effect.

The upper computer and the upper computer are divided into a user operation interface and a background data processing system. The user operation interface is divided into a dose rate display interface, a detection plane grid schematic diagram and a camera video interface. The background data processing system comprises a detection grid region code, a radiation positioning algorithm and a dosage rate algorithm.

The barrier-free array type radioactive source rapid positioning system has the detection mode that detected personnel pass through a detection area below a detector array at normal speed. The acquisition frequency of the positioning probe is 200ms, and the specific position of the person with radiation exceeding the standard is given in the fastest 1s, and the person with radiation exceeding the standard is recorded and photographed. The person who radiates normally passes through the device at normal speed without stopping.

The utility model relates to an integrated multiple radiation detector's positioning system, including the cylindrical sodium iodide crystal of 3 inches x 3 inches, 1 nuclide discernment sodium iodide crystal, 1 neutron pipe detector of 10 location. FIG. 1 is a simplified schematic diagram of a detector array, wherein a side auxiliary detector array may be mounted to the left or right of the main detector depending on the actual field.

The utility model discloses in concrete implementation, the detector array height is 3m, and detection area 4 is a 4 mx 1.8 m's space, and the detection plane is a 4 mx 4 m's accessible plane. The side detector array is centered on the detection side.

In one embodiment of the invention, the detector is suspended in the air at a height of 3m from the ground by a ceiling. The specific height can be finely adjusted according to the actual environment. The scope of embodiments of the present invention is not so limited. On the contrary, the embodiments of the invention are intended to embrace all such alterations, modifications and equivalents as fall within the spirit and scope of the appended claims.

In this embodiment, after the initial single crystal model is built, parameters such as the number of detectors, the shielding mode, the detector angle, and the like are modified. An optimal detector array model is found. The simulation results are shown in detail in fig. 2 and 3.

Example 2: on the basis of embodiment 1, fig. 4 is a schematic diagram of the result of the detector in an embodiment of the present invention. As shown in fig. 5, the detector mainly comprises 5 parts, a sodium iodide crystal probe 7, a cylindrical lead shielding layer 6, a PMT and signal amplification circuit board 5, and a detector protection shell. The cylindrical lead shielding layer 6 in this embodiment is 2cm thick and extends 5cm from the front end of the detector. The lead shielding mode is subjected to Monte Carlo simulation and experimental verification and is an optimal model.

The embodiment of the utility model provides an in lead shielding go out detector front end distance, not necessarily be 5 cm. And may vary depending on the particular installation environment. The scope of embodiments of the present invention is not so limited.

Fig. 5 is a schematic view of the installation position of the radioactive source positioning system according to an embodiment of the present invention, which only includes the sodium iodide detector array for positioning, as shown in fig. 5, each detector of the detector array has a certain angle change, and the angle change includes an up-down inclination angle and a left-right inclination angle. The up and down inclination angles are unified to be 45 degrees, and the left and right inclination angles are changed to a certain degree according to the installation position.

In one embodiment of the present invention, the nuclide identification detector is a 3 inch × 3 inch sodium iodide crystal, and the front end of the detector is not processed for improving the nuclide identification efficiency. The position is located off-center of the main array detector. The central position is lower, and more radioactive rays can be detected by being close to the detection plane without object shielding.

In one embodiment of the present invention, the neutron detector is a 3He gas detector with a diameter of 50mm × L600 mm. A layer of moderating body with a certain thickness is wrapped around the neutron detector to improve the neutron detection efficiency.

In one embodiment of the present invention, the camera is located under the main detector, and the field of view covers the whole 4m × 4m detection area. And after radiation alarm, video recording and snapshot actions are taken after radiation positioning information is received.

The utility model discloses an in the embodiment, the shell adopts the plastic-aluminum board, when protecting the detector main part, helps reducing the shielding effect of dustcoat to the ray, improve equipment's detection efficiency.

The thickness of the aluminum-plastic plate is 4 mm.

The upper computer is divided into a user interface and a background data processing interface. The background data includes positional feature codes of the array detector input when debugging with 137 Cs. And after debugging is finished, comparing the code of the actual source test with the Monte Carlo simulation calculation code, and correcting the simulation result to obtain a model correction parameter.

In the position feature coding, the codes comprise common industrial nuclide and medical nuclide. Each species includes 16 feature points at 4 different height planes. The height is 0m, 0.6m, 1.2m, 1.8 m.

When the radiation overproof personnel enter a detection area to trigger alarm, the position of the radiation overproof personnel is determined according to the position characteristic codes, position information is transmitted to the camera, the camera records and captures the radiation overproof personnel, and the video recording is stopped after the radiation alarm is released. The radiation alarm can be released manually, and when the radiation value is lower than the alarm value, the system can be automatically released. It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a quick positioning system of accessible array radiation source, includes main detector array (1), camera (2), vice detector array (3) and detection area (4), its characterized in that, main detector array (1) is installed to seven probe arrays, and the parallel pedestrian direction of central point position probe, vice detector array (3) are three probe arrays, and the perpendicular pedestrian direction of middle probe, detection area (4) are 4 mx 1.8 m's space, encode 4 mx 4 m's plane simultaneously, divide into 16 characteristic grids of 1 mx 1m, divide into 4 heights according to 1.8 m's height again, and total detection area has divided into 64 characteristic grids, encodes the radiation characteristic, and camera (2) are installed in the top of detection area (4).

2. The barrier-free array type radiation source rapid positioning system according to claim 1, wherein the main detector array (1) and the auxiliary detector array (3) are sodium iodide detector arrays with lead shielding.

3. The system of claim 2, wherein the lead shield has a thickness of 2cm and a forward extension distance of 5 cm.

4. The system of claim 1, wherein the probe comprises a housing, and a PMT and front-end signal amplification circuit (5), a cylindrical lead shield (6) and a sodium iodide crystal probe (7) mounted in the housing.

5. The system of claim 4, wherein the housing cover is made of aluminum-plastic plate with a thickness of 4 mm.