Radiation effect test system and method for camera photosensitive element

Abstract

The application discloses a radiation effect test system and method for a camera photosensitive element, and relates to the technical field of radiation effect test.The radiation effect test system for the camera photosensitive element comprises a radioactive source, a darkroom, a dark box, a camera A, a camera B and a computer; the darkroom can move horizontally and linearly relative to the ground to approach or move away from the radioactive source; the dark box is arranged in the darkroom, and the camera A and the camera B are arranged in cavities A and B of the dark box respectively.The method for testing the radiation effect of the camera photosensitive element in a radiation field comprises two sub-methods: 1. a method for testing the influence of different radiation dose rates on the image quality of the camera; and 2. a method for testing the radiation resistance of the camera photosensitive element.The application is used for testing the radiation effect of a specific model of camera photosensitive element in a radiation field, and is helpful to prolong the service life of the camera in a radiation environment and ensure the stable image quality of the camera in the radiation environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radiation effect test, in particular to a radiation effect test system and method for a camera photosensitive element. BACKGROUND

[0002] With the development of nuclear industry, more and more nuclear energy utilization and nuclear technology need to contact ionizing radiation environment. Since ionizing radiation can cause damage to the human body, remote operation and observation means are needed. The camera is an extension of the human eye, which can help people obtain necessary environmental condition information in the radiation environment. In the radiation environment, the radiation dose rate is not consistent everywhere. The closer to the radiation source, the higher the radiation dose rate. The farther away from the radiation source, the lower the radiation dose rate.

[0003] In the radiation environment, the photosensitive element (image sensor) of the camera will be affected by the radiation effect and produce radiation response, resulting in radiation noise in the shooting picture, and further causing the shooting picture quality to decrease. Generally speaking, the higher the radiation dose rate at the location of the camera, the more serious the picture quality decrease caused by single particle effect. The higher the total radiation dose received by the camera, the more serious the picture quality decrease caused by total radiation dose effect, and even the higher the probability of camera damage.

[0004] In the radiation environment, the camera performing the shooting task is usually carried on the nuclear robot and moves with the nuclear robot. In order to avoid the shooting picture quality of the camera being lower than expected (i.e. keeping the shooting picture quality of the camera always above an acceptable level), on the one hand, when the total radiation dose received by the camera reaches a certain value, the camera needs to be removed from the radiation field and replaced with a new camera to avoid the damage to the photosensitive element of the camera caused by nuclear radiation which is difficult to repair. On the other hand, considering the influence of radiation dose rate on the shooting picture quality of the camera, when planning the moving path of the robot in the radiation field (the camera is carried on the nuclear robot), the area with high radiation dose rate which causes serious picture quality loss should be avoided as much as possible.

[0005] In summary, it is necessary to design a reasonable and effective test system and method to explore (test) the radiation effect of the photosensitive element of the camera in the radiation field (the radiation effect includes the radiation resistance of the photosensitive element of the camera and the influence of different radiation dose rates on the shooting picture quality of the camera), which is very necessary to improve the service life of the camera in the radiation environment and ensure the stability of the shooting picture quality of the camera in the radiation environment. SUMMARY

[0006] The present application aims to overcome the deficiencies of the prior art, and provides a radiation effect test system and method for a camera photosensitive element, which is used to test the total radiation dose resistance of the camera photosensitive element and the influence of different radiation dose rates on the camera shooting picture quality.

[0007] The technical scheme of the present application is: a radiation effect test system for a camera photosensitive element, comprising a radioactive source, a darkroom, a dark box, a camera A, a camera B and a computer;

[0008] The radioactive source is directly or indirectly arranged on the ground;

[0009] The darkroom is movably arranged on the ground and can move horizontally and linearly relative to the ground to approach or move away from the radioactive source; a side wall of the darkroom opposite to the radioactive source is defined as wall A, a video test card and a light source are fixedly arranged on the wall A inside the darkroom, all the other walls of the darkroom except the wall A are defined as wall B, the wall A has the property of being penetrable by rays, the wall B has the property of shielding rays, and the wall A and the wall B both have the property of shielding visible light;

[0010] The dark box is arranged inside the darkroom, the dark box has an inner cavity A and an inner cavity B, a radiation dose meter is fixedly arranged outside the dark box, a lens extension hole A communicating with the inner cavity A and a lens extension hole B communicating with the inner cavity B are arranged outside the dark box, the lens extension hole A and the lens extension hole B are both arranged opposite to the wall A of the darkroom, the distance between the lens extension hole A and the wall A of the darkroom is equal to the distance between the lens extension hole B and the wall A of the darkroom, and the wall of the dark box has the properties of shielding rays and shielding visible light;

[0011] The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively, the photosensitive element of the camera A is opposite to the lens extension hole A and the rays emitted by the radioactive source, and the camera A is used to shoot the patterns on the video test card; the photosensitive element of the camera B is arranged opposite to the lens extension hole B and the rays emitted by the radioactive source, and the camera B is used to shoot a dark image;

[0012] The computer is arranged outside the darkroom in a region not irradiated by the radioactive source, and is in communication connection with the camera A and the camera B through a video capture card.

[0013] The further technical scheme of the present application is: the video test card contains color information for verifying color change and gray information for verifying resolution change, the gray information is arranged at the upper and lower ends of the color information; the color information is different color blocks arranged in a rectangular array, the colors of any two adjacent blocks are different, and the gray information is a color bar with gradually decreasing gray levels from one end to the other end in the horizontal direction.

[0014] The further technical scheme of the present application is that the dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out, the threading hole A and the threading hole B are communicated to the inner cavity A and the inner cavity B respectively, and the wall surface B of the dark chamber is provided with a threading hole C for the data line and the power line to pass through; the data line and the power line of the camera A extend out to the outside of the dark chamber by passing through the threading hole A and the threading hole C in sequence; and the data line and the power line of the camera B extend out to the outside of the dark chamber by passing through the threading hole B and the threading hole C in sequence.

[0015] The further technical scheme of the present application is that the dark chamber is movably installed on the ground through the sliding table at the lower end.

[0016] The further technical scheme of the present application is that the dark box is movably installed on the bottom surface of the inner cavity of the dark chamber through the scissor type lifting frame at the lower end, and the camera A captures images of different height intervals of the video test card by moving up and down with the dark box.

[0017] The technical scheme of the present application is a method for testing the radiation effect of a camera photosensitive element in a radiation field, which is applied to the radiation effect test system for the camera photosensitive element.

[0018] The method comprises two sub-methods: 1. a method for testing the influence of different radiation dose rates on the image quality of a camera; and 2. a method for testing the radiation resistance performance of a camera photosensitive element.

[0019] The first sub-method comprises the following steps:

[0020] S01, measuring the radiation dose rate of each experimental point:

[0021] Select no less than x experimental points in the moving stroke of the dark chamber, x>=3, and sequentially name the x experimental points as n1, n2,..., nx from far to near to the radiation source. x Respectively measure the radiation dose rate at the outer surface of the dark box when the dark chamber is at each experimental point. x The radiation dose rate of each experimental point changes linearly, the experimental point n1 farthest to the radiation source has the lowest radiation dose rate, and the experimental point nx closest to the radiation source has the highest radiation dose rate. x

[0022] In this step, the camera A and the camera B are not installed in the dark box when the radiation dose rate is measured by the radiation dose meter.

[0023] In this step, the radiation dose rate is calculated by formula 1: δ=∑ / t; in the formula, δ is the radiation dose rate, ∑ is the total radiation dose received by the radiation dose meter, and t is the time length for the radiation dose meter to receive radiation.

[0024] S02, shooting video data: ​

[0025] 1. First, adjust camera A and camera B to fixed focus mode, then install camera A and camera B into the inner cavity A and inner cavity B of the dark box respectively, and ensure that the video test card occupies the entire field of view of camera A;

[0026] 2. Then, according to the order from experiment point n1 to experiment point n x , collect the video data of the dark room at each experiment point through the video capture card in sequence, and the video data of each experiment point contains a group of video data shot by camera A and a group of video data shot by camera B, and the above two groups of video data contain a series of video data collected at different exposure times respectively;

[0027] In this step, under the condition of the same radiation dose rate, the longer the exposure time, the greater the cumulative noise in the video, and the shorter the exposure time, the smaller the cumulative noise in the video;

[0028] In this step, the models and all setting parameters of camera A and camera B are consistent, the video shot by camera A is the video test card image, and the video shot by camera B is the dark image; the total radiation dose received by camera A and camera B at the same time is consistent, and the total radiation dose received by the radiation dose meter is regarded as the total radiation dose received by camera A or camera B;

[0029] S03, analyze image quality: determine the image quality of the above two groups of video data based on the EMVA1288 standard, the EMVA1288 standard characterizes the image quality of the video by outputting 6 image quality indicators, and the 6 image quality indicators are quantum efficiency, dark noise, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio. Among them, the video data shot by camera A after processing obtains the information of quantum efficiency, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, and the video data shot by camera B after processing obtains the information of dark noise;

[0030] S04, determine the influence of different radiation dose rates on camera image quality: correlate the three types of data of the radiation dose rate of each experiment point, the video exposure time, and the 6 image quality indicators obtained based on the EMVA1288 standard, thereby establishing the corresponding relationship between the radiation dose rate, the exposure time and the image quality;

[0031] The second sub-method step is as follows:

[0032] S01, select experiment points in a suitable radiation dose rate interval:

[0033] 1. Select no less than 3 experimental points in the moving stroke of the dark chamber, and respectively measure the radiation dose rate at the surface of the dark chamber when the dark chamber is at each experimental point; the radiation dose rates of the experimental points change linearly, the experimental point farthest from the radioactive source has the lowest radiation dose rate, and the experimental point closest to the radioactive source has the highest radiation dose rate;

[0034] 2. In the interval of 60-200 Gy / h of the radiation dose rate, select an experimental point for subsequent testing, and name the selected experimental point as n i ;

[0035] In this step, when the radiation dose rate is measured by the radiation dosimeter, neither camera A nor camera B is installed in the dark chamber;

[0036] In this step, the radiation dose rate is calculated by formula 1: δ = ∑ / t; in the formula, δ is the radiation dose rate, ∑ is the total radiation dose received by the radiation dosimeter, and t is the time length of the radiation received by the radiation dosimeter;

[0037] S02, shoot video data:

[0038] 1. First, pause the radiation, adjust camera A and camera B to the fixed focus mode, and then install camera A and camera B into the inner cavities A and B of the dark chamber respectively, and ensure that the video test card occupies the entire field of view of camera A;

[0039] 2. Then, move the dark chamber to the position of experimental point n i , first collect a group of video data in a non-radiation environment through the video capture card; then start the radiation, and collect multiple groups of video data when the total radiation dose reaches a plurality of specific nodes through the video capture card, one group of video data for each node, each group of video data containing the video test card image shot by camera A and the dark image shot by camera B;

[0040] In this step, the models and all setting parameters of camera A and camera B are consistent; the total radiation dose received by camera A and camera B at the same time is consistent, and the total radiation dose received by the radiation dosimeter is regarded as the total radiation dose received by camera A or camera B;

[0041] In this step, when the total radiation dose reaches a specific node, first pause the radiation, and then collect video data, so as to ensure that the total radiation dose does not rise in the time period of collecting video data;

[0042] S03, analyze image quality: determine the image quality of all groups of video data based on the EMVA1288 standard, which characterizes the image quality of the video by outputting 6 image quality indicators, and the 6 image quality indicators are quantum efficiency, dark noise, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, wherein the video data captured by camera A is processed to obtain information about quantum efficiency, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, and the video data captured by camera B is processed to obtain information about dark noise;

[0043] S04, determine the radiation resistance of the camera photosensitive element: correlate the total radiation dose value of each node with the 6 image quality indicators obtained based on the EMVA1288 standard, thereby establishing a corresponding relationship between the total radiation dose and the image quality.

[0044] A further technical solution of the present application is that in the S02 step of the first sub-method, when the total radiation dose received by the radiation dosimeter is greater than 30Gy, the radiation is first suspended, new cameras of the same model are replaced for camera A and camera B respectively, and then the radiation is restarted to re-shoot the current video interrupted.

[0045] A further technical solution of the present application is that in the S02 step of the second sub-method, the video shooting time of camera A and camera B is 5 minutes, and the video frame number is not less than 300 frames.

[0046] A further technical solution of the present application is that in the S02 step of the second sub-method, 6 groups of video data are collected by the video capture card when the total radiation dose reaches 30Gy, 50Gy, 80Gy, 100Gy, 150Gy and 200Gy respectively.

[0047] Compared with the prior art, the present application has the following advantages:

[0048] 1. It is used for testing the radiation effect of a specific model of camera photosensitive element in a radiation field, which helps to improve the service life of the camera in a radiation environment and ensure the stability of the camera in a radiation environment. The test of the radiation effect includes the test of the radiation resistance of the camera photosensitive element and the test of the influence of different radiation dose rates on the camera shooting picture quality.

[0049] 2. Through the test of the radiation resistance of the camera photosensitive element, the corresponding relationship between the total radiation dose and the image quality is established, which has guiding significance for evaluating the working time of the camera in the radiation field and the replacement time, avoiding the decline of the camera shooting picture quality due to receiving excessive total radiation dose, and avoiding the damage of the camera components due to receiving excessive total radiation dose.

[0050] 3. Through the test of the influence of different radiation dose rates on the picture quality of the camera, the corresponding relationship among the radiation dose rate, the exposure time and the image quality is established, which is of guiding significance for planning the moving path of the nuclear robot in the radiation field and making the camera avoid the area with too high radiation dose rate, thereby ensuring the stability of the picture quality of the camera in the radiation field.

[0051] The application will be further described in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 It is a structural schematic diagram of the application;

[0053] Figure 2 It is a structural schematic diagram of the dark box and an installation position schematic diagram;

[0054] Figure 3 It is a pattern schematic diagram of the video test card.

[0055] Legend: radioactive source 1; dark room 2; wall surface A21; wall surface B22; threading hole C23; dark box 3; inner cavity A31; inner cavity B32; threading hole A33; threading hole B34; camera A41; camera B42; computer 5; sliding table 100; video test card 200; light source 300; video capture card 400; radiation dose meter 500; scissor type lifting device 600. DETAILED DESCRIPTION

[0056] Example 1:

[0057] As shown in the figure, the radiation effect test system for the photosensitive element of the camera includes the radioactive source 1, the dark room 2, the dark box 3, the camera A41, the camera B42 and the computer 5. Figures 1-3 The radioactive source 1 is a Co-60 gamma ray radioactive source, which is in the source library underground when not in use, and is raised to the irradiation room above the ground when in use.

[0058] The irradiation area in the irradiation room is located in the irradiation room. Figure 1

[0059] ​The darkroom 2 is movably installed on the ground through a sliding table 100 (which is a linear motor sliding table or a screw nut sliding table) at the lower end, which can move horizontally and linearly relative to the ground to approach or move away from the radiation source 1. A side wall surface of the darkroom 2 opposite to the radiation source 1 is defined as a wall surface A21, and a video test card 200 and a light source 300 are fixedly arranged on the wall surface A21 inside the darkroom 2. The wall surfaces of the darkroom 2 other than the wall surface A21 are wall surfaces B22. The wall surface A21 has the property of being penetrable by rays, the wall surfaces B22 have the property of shielding rays, and the wall surfaces A21 and the wall surfaces B22 have the property of shielding visible light. Based on the structural design of the darkroom 2, on the one hand, the rays emitted by the radiation source 1 can only enter the inside through the wall surface A21, and the rays entering through the wall surface A21 can be considered as rays directly opposite the photosensitive elements of the camera, and the rays entering the photosensitive elements of the camera from non-direct angles are shielded by the wall surface B22, so as to facilitate the accurate dose camera photosensitive element to receive the total radiation dose of the radiation dosimeter, and further improve the accuracy of the test results to a certain extent. On the other hand, the wall surfaces A21 and the wall surfaces B22 are made of light shielding materials, so as to avoid the influence of external visible light on dark image acquisition.

[0060] The dark box 3 is arranged inside the darkroom 2, and the dark box 3 is internally provided with an inner cavity A31 and an inner cavity B32. The dark box 3 is externally fixedly provided with a radiation dosimeter 500 (which is an offline type thin film dosimeter). The dark box 3 is externally provided with a lens extension hole A communicating with the inner cavity A31 and a lens extension hole B communicating with the inner cavity B32. The lens extension hole A and the lens extension hole B are arranged opposite to the wall surface A21 of the darkroom 2, and the distances between the lens extension hole A and the lens extension hole B and the wall surface A21 of the darkroom 2 are equal. The wall surface of the dark box 3 has the properties of shielding rays and shielding visible light. Based on the structural design of the dark box 3, the rays outside the dark box 3 can only enter the inner cavity A31 and the inner cavity B32 through the lens extension hole A and the lens extension hole B respectively. The rays entering the inner cavity A31 through the lens extension hole A are basically absorbed by the photosensitive elements of the camera A41, and the rays entering the inner cavity B32 through the lens extension hole B are basically absorbed by the photosensitive elements of the camera B42, so as to avoid the other components of the camera receiving radiation to a greater extent.

[0061] Camera A41 and camera B42 are arranged in inner cavity A31 and inner cavity B32 of dark box 3 respectively, the photosensitive element of camera A41 is opposite to lens extension hole A and is opposite to the rays emitted by radiation source 1 (the rays emitted by radiation source 1 are vertically incident on the photosensitive element of camera A41), camera A41 is used for shooting the patterns on video test card 200. The photosensitive element of camera B42 is provided with shading material (shading cloth), the lens of camera B42 is removed, the photosensitive element of camera B42 is arranged opposite to lens extension hole B and is opposite to the rays emitted by radiation source 1 (the rays emitted by radiation source 1 are vertically incident on the photosensitive element of camera B42), camera B42 is used for shooting dark image.

[0062] Computer 5 is arranged in the area outside darkroom 2 which is not irradiated by radiation source 1, and is connected with camera A41 and camera B42 in communication respectively through video capture card 400 (the video capture card 400 is DVR video recorder, and the DVR video recorder is placed in the area which is not irradiated by radiation source 1).

[0063] Preferably, one end of the sliding table 100 is opposite to the center position of the radiation source 1, so that the sliding table 100 is parallel to the direction of the rays where it is located.

[0064] Preferably, the video test card 200 contains color information for verifying color change and gray scale information for verifying resolution change, and the gray scale information is arranged at the upper and lower ends of the color information; the color information is different color blocks arranged in rectangular array, the color of any two adjacent blocks is different, and the number of color blocks is not less than 20; the gray scale information is color bars with gradually decreasing gray scale from one end to the other end in horizontal direction, and the number of color bars is not less than 128.

[0065] Preferably, the light source 300 is a backlight LED lamp, which is installed between the video test card 200 and the wall surface A21 of the darkroom 2, so that camera A41 can clearly shoot the patterns on the video test card 200.

[0066] Preferably, the dark box 3 is provided with threading holes A33 and B34 for data line and power line to extend out, the threading holes A33 and B34 are communicated to inner cavity A31 and inner cavity B32 respectively, and the wall surface B22 of the darkroom 2 is provided with threading hole C23 for data line and power line to pass through; the data line and power line of camera A41 extend out to the outside of the darkroom 2 by passing through threading hole A33 and threading hole C23 in turn, and the data line and power line of camera B42 extend out to the outside of the darkroom 2 by passing through threading hole B34 and threading hole C23 in turn.

[0067] Preferably, the dark box 3 is movably installed on the bottom surface of the inner cavity of the darkroom 2 through the scissor type lifting device 600 at the lower end, and camera A41 shoots the images of different height intervals of the video test card 200 by moving with the lifting of the dark box 3.

[0068] Briefly describe the application of this invention:

[0069] A method for testing the radiation effect of a camera's image sensor in a radiation field is applied to the aforementioned radiation effect testing system for camera image sensors. The method includes the following two sub-methods: 1. A method for testing the effect of different radiation dose rates on camera image quality; 2. A method for testing the radiation resistance performance of the camera's image sensor.

[0070] The steps of the first sub-method are as follows:

[0071] S01, Measure the radiation dose rate at each experimental point:

[0072] Ten experimental points were selected during the movement within the darkroom, and these ten points were named n1, n2, ..., n in order of their distance from the radiation source. 10 The radiation dose rate at the outer surface of the darkroom was measured at each experimental point; from experimental point n1 to experimental point n... 10 The radiation dose rate at each experimental point showed a linear variation. The experimental point n1, which was farthest from the radiation source, had the lowest radiation dose rate, while the experimental point n, which was closest to the radiation source, had the lowest radiation dose rate. 10 The radiation dose rate is the highest.

[0073] In this step, when the radiation dose rate is measured using a radiation dosimeter, neither camera A nor camera B is placed inside the dark box.

[0074] In this step, the radiation dose rate is calculated using Formula 1: δ=∑ / t; where δ is the radiation dose rate, ∑ is the total radiation dose received by the radiation dosimeter, and t is the duration of radiation received by the radiation dosimeter.

[0075] S02, Video Data:

[0076] 1. First, adjust camera A and camera B to fixed focus mode, then install camera A and camera B into cavity A and cavity B of the dark box respectively, ensuring that the video test card occupies the entire field of view of camera A.

[0077] 2. Then, according to the sequence from experimental point n1 to experimental point n 10 In the order of the video capture card, video data at each experimental point in the darkroom is collected sequentially. The video data at each experimental point includes a set of video data captured by camera A and a set of video data captured by camera B. The two sets of videos are respectively contained in a series of video data collected at different exposure times.

[0078] In this step, under the same radiation dose rate, the longer the exposure time, the greater the cumulative noise in the video; the shorter the exposure time, the smaller the cumulative noise in the video.

[0079] In this step, the models and all setting parameters of camera A and camera B are consistent, the video captured by camera A is the video test card image, and the video captured by camera B is the dark image; the total radiation dose received by the radiation dosimeter is consistent with the total radiation dose received by the photosensitive element of camera A or the photosensitive element of camera B at the same time.

[0080] In this step, when the total radiation dose received by the radiation dosimeter is greater than 30 Gy, the radiation is first suspended (the radioactive source can be lowered into the source library underground), new cameras of the same model are replaced for camera A and camera B respectively, and then the radiation is started again (the radioactive source can be raised to the irradiation chamber above the ground), and the current video interrupted is re-shot.

[0081] S03, analyze image quality: determine the image quality of the above two groups of video data based on the EMVA1288 standard, which characterizes the image quality of the video by outputting 6 image quality indicators, and the 6 image quality indicators are quantum efficiency, dark noise, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio. Among them, the video data captured by camera A after processing obtains information of quantum efficiency, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, and the video data captured by camera B after processing obtains information of dark noise.

[0082] S04, determine the influence of different radiation dose rates on the image quality of the camera: correlate the three types of data of the radiation dose rate of each experimental point, the video exposure time, and the 6 image quality indicators obtained based on the EMVA1288 standard, thereby establishing the corresponding relationship between the radiation dose rate, the exposure time and the image quality.

[0083] The second sub-method step is as follows:

[0084] S01, select experimental points in a suitable radiation dose rate interval:

[0085] 1. Select 3 experimental points in the moving stroke of the darkroom, and measure the radiation dose rate at the surface of the dark box when the darkroom is at each experimental point; the radiation dose rate of each experimental point changes linearly, and the experimental point farthest from the radioactive source has the lowest radiation dose rate, and the experimental point closest to the radioactive source has the highest radiation dose rate;

[0086] 2. Select an experimental point in the interval of 60-200 Gy / h for subsequent testing, and the selected experimental point is named n i .

[0087] In this step, when the radiation dose rate is measured by the radiation dosimeter, neither camera A nor camera B is installed in the dark box.

[0088] In this step, the radiation dose rate is calculated by formula 1: δ = ∑ / t; where δ is the radiation dose rate, ∑ is the total dose received by the radiation dosimeter, and t is the time length during which the radiation dosimeter receives radiation.

[0089] S02, shooting video data:

[0090] 1. First, pause the radiation (lower the radiation source into the source library underground), adjust camera A and camera B to the fixed focus mode, and then install camera A and camera B into the inner cavities A and B of the dark box respectively, and ensure that the video test card occupies the entire field of view of camera A.

[0091] 2. Then move the darkroom to the experimental point n i location, first collect a group of video data in a non-radiation environment through the video capture card; then start the radiation (raise the radiation source above the ground), and collect six groups of video data when the total radiation dose reaches 30Gy, 50Gy, 80Gy, 100Gy, 150Gy and 200Gy through the video capture card; at this time, a total of seven groups of video data are collected, each group of video data contains video test card images taken by camera A and dark images taken by camera B.

[0092] In this step, the models and all setting parameters of camera A and camera B are consistent; the total radiation dose received by camera A and camera B at the same time is consistent, and the total radiation dose received by the radiation dosimeter is regarded as the total radiation dose received by camera A or camera B.

[0093] In this step, when the total radiation dose reaches a certain node (the certain node is 30Gy, 50Gy, 80Gy, 100Gy, 150Gy and 200Gy), first pause the radiation, and then collect video data to ensure that the total radiation dose does not rise during the time period of collecting video data.

[0094] In this step, the video shooting time of camera A and camera B is 5 minutes, and the video frame number is not less than 300 frames.

[0095] S03, analyze image quality: determine the image quality of all groups of video data based on the EMVA1288 standard, which represents the image quality of the video through six image quality indicators, and the six image quality indicators are quantum efficiency, dark noise, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio. Among them, the video data taken by camera A after processing obtains the information of quantum efficiency, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, and the video data taken by camera B after processing obtains the information of dark noise.

[0096] S04, determining the radiation resistance of the camera photosensitive element: the total radiation dose value corresponding to each node is associated with the six image quality indicators obtained based on the EMVA1288 standard, thereby establishing a corresponding relationship between the total radiation dose and the image quality.

Claims

1. A system for testing the radiation effects on the photosensitive elements of a video camera, characterized in that it comprises: The radiation source, the darkroom, the dark box, the camera A, the camera B and the computer are included. The radiation source is directly or indirectly arranged on the ground. The darkroom is movably arranged on the ground and can move horizontally relative to the ground to approach or move away from the radiation source. The wall surface A of the darkroom is provided with a video test card and a light source. The dark box is arranged in the darkroom, and the dark box is provided with an inner cavity A and an inner cavity B. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively.

2. The radiation effect testing system for a camera photosensitive element of claim 1, wherein: The computer is arranged outside the darkroom and is not irradiated by the radiation source.

3. A system for testing the effects of radiation on a camera photosensitive element as claimed in claim 1 or 2, characterized in that: The gray scale information is arranged at the upper and lower ends of the color information.

4. The radiation effect testing system for a camera photosensitive element of claim 3, wherein: The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out.

5. The radiation effect testing system for a camera photosensitive element of claim 4, wherein: The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power line to extend out. The data line and the power line of the camera A extend out through the threading hole A and the threading hole C. The camera A and the camera B are arranged in the inner cavity A and the inner cavity B of the dark box respectively. The camera A is arranged in the inner cavity A of the dark box, and the photosensitive element of the camera A is opposite to the lens extension hole A and the radiation emitted by the radiation source. The camera B is arranged in the inner cavity B of the dark box, and the photosensitive element of the camera B is provided with a shading material. The computer is arranged outside the darkroom and is not irradiated by the radiation source. The gray scale information is arranged at the upper and lower ends of the color information. The color information is a rectangular array of different color blocks, and the color of any two adjacent blocks is different. The dark box is provided with a threading hole A and a threading hole B for the data line and the power S01, measure the radiation dose rate of each experimental point: Select no less than x experimental points in the moving stroke of the darkroom, x≥3, and name these x experimental points in the order of distance from far to near as n1, n2, ···, n x , respectively, and measure the radiation dose rate at the surface of the darkroom when the darkroom is at each experimental point; the radiation dose rate of each experimental point changes linearly from the experimental point n x 1 to the experimental point n x , the experimental point n1 farthest from the radiation source has the lowest radiation dose rate, and the experimental point n closest to the radiation source has the highest radiation dose rate; In this step, when measuring the radiation dose rate by the radiation dosimeter, neither camera A nor camera B is installed in the dark box; In this step, the radiation dose rate is calculated by formula 1: δ = ∑ / t; in the formula, δ is the radiation dose rate, ∑ is the total radiation dose received by the radiation dosimeter, and t is the time length during which the radiation dosimeter receives radiation; S02, shoot video data:

1. First, adjust camera A and camera B to fixed focus mode, then install camera A and camera B into the inner cavities A and B of the dark box respectively, and ensure that the video test card occupies the entire field of view of camera A; 2. According to the order from the experimental point n1 to the experimental point n x , the video data of the darkroom at each experimental point is sequentially collected by the video capture card, and the video data of each experimental point contains a group of video data shot by the camera A and a group of video data shot by the camera B, and the above two groups of video data contain a series of video data collected at different exposure times, respectively. In this step, under the condition of the same radiation dose rate, the longer the exposure time, the greater the cumulative noise in the video, and the shorter the exposure time, the smaller the cumulative noise in the video; In this step, the models and all setting parameters of camera A and camera B are consistent, the video shot by camera A is the video test card image, and the video shot by camera B is the dark image; the total radiation dose received by the radiation dosimeter is consistent with the total radiation dose received by camera A or camera B at the same time, and the total radiation dose received by the radiation dosimeter is regarded as the total radiation dose received by camera A or camera B; S03, analyze image quality: determine the image quality of the above two groups of video data based on the EMVA1288 standard, which represents the image quality of the video by outputting six image quality indicators, i.e., quantum efficiency, dark noise, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, wherein the video data shot by camera A is processed to obtain information of quantum efficiency, saturation capacity, absolute sensitivity threshold, dynamic range and signal-to-noise ratio, and the video data shot by camera B is processed to obtain information of dark noise; S04, determine the influence of different radiation dose rates on camera image quality: correlate the three types of data, i.e., the radiation dose rate of each experimental point, the video exposure time and the six image quality indicators obtained based on the EMVA1288 standard, to establish the corresponding relationship among "radiation dose rate-exposure time-image quality"; The second sub-method step is as follows: S01, select experimental points in a suitable radiation dose rate range:

1. Select no less than three experimental points in the moving stroke of the darkroom, and measure the radiation dose rate at the surface of the dark box when the darkroom is at each experimental point; the radiation dose rates of the experimental points change linearly, the experimental point farthest from the radiation source has the lowest radiation dose rate, and the experimental point closest to the radiation source has the highest radiation dose rate; 2. In the interval of radiation dose rate of 60-200 Gy / h, an experimental point is selected for subsequent testing, and the selected experimental point is named n i ; In this step, when measuring the radiation dose rate by the radiation dosimeter, neither camera A nor camera B is installed in the dark box; In this step, the radiation dose rate is calculated by formula 1: δ = ∑ / t; in the formula, δ is the radiation dose rate, ∑ is the total radiation dose received by the radiation dosimeter, and t is the time length during which the radiation dosimeter receives radiation; S02, shoot video data:

1. First, pause the radiation, adjust camera A and camera B to fixed focus mode, and then install camera A and camera B into the inner cavity A and inner cavity B of the dark box respectively, ensuring that the video test card occupies the entire field of view of camera A.

2. Move the darkroom to experiment point n i The location, first through the video capture card to collect a group of video data in the absence of radiation environment; then start radiation, through the video capture card to collect a plurality of groups of video data when the total dose of radiation reaches a specific node, a group of video data is collected at each node, and each group of video data contains a video test card image taken by camera A and a dark image taken by camera B; In this step, the models and all settings parameters of camera A and camera B are the same; the total radiation dose received by camera A and camera B at the same time is the same, and the total radiation dose received by the radiation dosimeter is regarded as the total radiation dose received by camera A or camera B. In this step, when the total radiation dose reaches a specific point, radiation is paused before video data is collected to ensure that the total radiation dose does not increase during the video data collection period. S03, Image Quality Analysis: Based on the EMVA1288 standard, the image quality of all the above groups of video data is determined. The EMVA1288 standard characterizes the image quality of the video by outputting six image quality indicators, namely quantum efficiency, dark noise, saturation capacity, absolute sensitivity threshold, dynamic range, and signal-to-noise ratio. Among them, the video data captured by camera A is processed to obtain information on quantum efficiency, saturation capacity, absolute sensitivity threshold, dynamic range, and signal-to-noise ratio, while the video data captured by camera B is processed to obtain information on dark noise. S04, Determine the radiation resistance of the camera's image sensor: Associate the total radiation dose value corresponding to each node with the six image quality indicators obtained based on the EMVA1288 standard to establish the correspondence between "total radiation dose - image quality".

7. The method of testing radiation effects in radiation fields of a photosensitive element of a camera as claimed in claim 6, characterized in that: In step S02 of the first sub-method, when the total radiation dose received by the radiation dosimeter exceeds 30 Gy, radiation is first paused, and new cameras of the same model are replaced for both camera A and camera B. Then, radiation is restarted, and the interrupted current video is re-recorded.

8. The method of testing radiation effects in radiation fields of a photosensitive element of a camera as claimed in claim 7, characterized in that: In step S02 of the second sub-method, the video duration of both camera A and camera B is 5 minutes, and the number of video frames is no less than 300.

9. The method of testing radiation effects in radiation fields of a photosensitive element of a camera as claimed in claim 8, characterized in that: In step S02 of the second sub-method, six sets of video data are collected using a video acquisition card when the total radiation dose reaches 30Gy, 50Gy, 80Gy, 100Gy, 150Gy and 200Gy respectively.

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