Online low-temperature irradiation test method based on infrared focal plane ionization total dose effect

Abstract

The invention relates to an on-line low-temperature irradiation test method based on an infrared focal plane ionization total dose effect, a test device involved in the method is composed of a test hall and an irradiation hall, whether a cold screen is installed in a special test Dewar flask or not is selected according to the requirements of a test dark field or a light field, and then the test hall is started; then a molecular pump is used for exhausting a special test Dewar flask packaged with an infrared focal plane, liquid nitrogen is filled for refrigeration, an irradiation test is started, test software integration time is set, images are continuously collected and stored in a computer, irradiation is stopped after a certain preset test fluence point is irradiated, then different integration time is changed, and a test result is obtained. The method comprises the following steps: respectively carrying out dark field and light field tests, continuously acquiring images and storing the images in a computer, stopping irradiation and ending an irradiation test until a preset maximum irradiation fluence is reached, and calculating dark current, output signals, dark current noise, response rate, detection rate and defect pixels by utilizing an existing parameter calculation method and combining the acquired images. According to the invention, the low-temperature on-line irradiation test of the infrared focal plane is realized, the reliability is high, the device connection is simple, the operation is convenient, and the method is simple and feasible.

Description

Technical Field

[0001] The invention relates to an online low-temperature irradiation test method based on infrared focal plane ionization total dose effect, and belongs to the technical field of infrared focal plane parameter detection. Background Art

[0002] The infrared focal plane is a key core component of space optical satellites. Space early warning satellites, reconnaissance satellites, remote sensing and resource exploration satellites and other projects have all put forward the need for infrared focal planes.

[0003] In space applications, the infrared focal plane is irradiated by high-energy particles in the space radiation environment, which will cause radiation damage to the device, resulting in performance degradation such as increased noise level, increased dark current, decreased detection rate, and even functional failure, thus affecting the accuracy and reliability of the entire space photoelectric detection system. The main components of high-energy particles in the space radiation environment are electrons, protons, and heavy ions. Spacecraft have been serving in space for a long time. With the accumulation of radiation dose, the infrared focal plane will produce a total ionizing dose effect. Therefore, it is urgent to use radiation sources on the ground to simulate the radiation effect of high-energy particles in the space radiation environment, study the displacement damage effect of the infrared focal plane through radiation tests, analyze the mechanism of radiation-induced defects, and thus reveal the displacement damage mechanism of the infrared focal plane.

[0004] Since infrared materials are narrow bandgap semiconductors with direct bandgap, background thermal excitation will seriously affect the movement of carriers inside the material, resulting in an increase in the noise level of the infrared focal plane, which directly affects the performance of the infrared focal plane. Therefore, the infrared focal plane is very sensitive to temperature and must work in a low temperature environment to reduce the impact of background noise on device performance. At the same time, temperature changes will directly affect the interaction between radiation-induced defects and intrinsic defects inside the material, and have a direct effect on the formation of double vacancies and defect clusters inside the material and the recombination of interstitial atoms, thereby causing huge changes in the carrier concentration, lifetime, mobility and lattice structure inside the material.

[0005] The total ionization dose effect of electronic components was studied using 60The Coγ-ray irradiation source conducts ground simulation irradiation tests. Unlike high-energy particles such as protons, when the γ-ray irradiation source starts the irradiation test, all objects inside the entire irradiation hall are irradiated by γ-rays. When testing the performance parameters of the infrared focal plane, data acquisition and timing control circuits are required to control the bias and timing of the device. The data acquisition and timing control circuits are composed of various semiconductor components and are very sensitive to radiation. The radiation damage caused by radiation will cause the circuit function to fail, making it impossible to complete the infrared focal plane performance parameter test. At the same time, since the output signal of the infrared focal plane is weak and easily interfered, thus affecting the integrity of the output signal, the connection between the data acquisition and timing control circuit and the infrared focal plane needs to be as short as possible, which will result in the data acquisition and timing control circuits having to be placed in the radiation environment of the irradiation hall. Therefore, the radiation safety of the data acquisition and timing control circuits must be considered.

[0006] In summary, during the irradiation test of the total ionization dose effect of the infrared focal plane, the infrared focal plane must be kept in a low temperature environment. At the same time, in order to obtain the degradation law of the performance parameters of the infrared focal plane during the irradiation process, the long-distance online testing technology must be solved, and the radiation safety of the data acquisition and timing control circuit must be guaranteed. At present, the existing radiation sources do not have the above test conditions, and it is impossible to carry out the study of the total ionization dose effect of the infrared focal plane. Therefore, it is necessary to establish an online low-temperature irradiation test device for the total ionization dose effect of the infrared focal plane. Summary of the invention

[0007] The purpose of the present invention is to provide an online low-temperature irradiation test method based on the total dose effect of infrared focal plane ionization. The test device involved in the method is composed of a test hall and an irradiation hall. The method first places the device in the irradiation hall and the test hall, connects cables according to the test principle, and then selects whether to install a cold screen in a special test dewar according to the requirements of testing a dark field or a light field. Then, a molecular pump is used to exhaust the special test dewar encapsulated with an infrared focal plane, and liquid nitrogen is filled for refrigeration. After checking that all functions are normal, the irradiation test is started, the test software integration time is set to 300 μs, images are continuously collected and saved in a computer, and after irradiating to a preset test injection point, the irradiation is stopped, and then different integration times are changed to perform dark field and light field tests respectively. At the same time, images are continuously collected and saved in the computer until a predetermined maximum irradiation injection is reached, the irradiation is stopped, and the irradiation test is ended. The existing parameter calculation method is used to calculate the dark current, output signal, dark current noise, response rate, detection rate and defective pixels in combination with the collected images. The present invention realizes the low-temperature online irradiation test of the infrared focal plane, which has high reliability, simple device connection, convenient operation and simple and easy method. The device involved has the characteristics of small size, light weight and portability, and can realize the off-site infrared focal plane performance parameter test, and meet the requirements of the online low-temperature irradiation test of the total ionizing dose effect of the infrared focal plane.

[0008] The present invention discloses an online low-temperature irradiation test method based on the total dose effect of infrared focal plane ionization. The test device involved in the method is composed of a test hall and an irradiation hall. The test hall is provided with a computer (1), a low-noise DC power supply (2), a GPIB to USB connection line (3), a camlink data line (5), a first wire (6), a second wire (10), an oscilloscope (11) and a coaxial cable (12); the irradiation hall is provided with a data acquisition and timing control circuit (4), a special test Dewar flask (7), a CDBA-25Z cable (8), a ray shielding device (13) and an irradiation source. The computer (1) and the low-noise DC power supply (2) are connected via the GPIB to USB connection line (3). The computer (1) and the data acquisition and timing control circuit (4) are connected by a USB connection line (3), the computer (1) and the data acquisition and timing control circuit (4) are connected by a camlink data line (5), the low-noise DC power supply (2) and the data acquisition and timing control circuit (4) are connected by a first wire (6), the data acquisition and timing control circuit (4) and the special test dewar flask (7) are connected by a CDBA-25Z cable (8), the special test dewar flask (7) and the DC power supply (9) are connected by a second wire (10), the special test dewar flask (7) and the oscilloscope (11) are connected by a coaxial cable (12), and a radiation shielding device (13) is provided on the periphery of the data acquisition and timing control circuit (4). The specific operation is carried out according to the following steps:

[0009] a. To test the dark field characteristics of the infrared focal plane, a cold shield needs to be placed in the Dewar flask; to test the light field characteristics of the infrared focal plane, a cold shield does not need to be placed in the Dewar flask. Before the irradiation test begins, a molecular pump is used to exhaust the special test Dewar flask (7) encapsulating the infrared focal plane, and the flask is filled with liquid nitrogen for cooling;

[0010] b. Calculate the distance between the special test dewar (7) and the radiation source according to the preset irradiation dose rate, place the special test dewar (7), fill the special test dewar (7) with liquid nitrogen, measure the PT100 resistance value in the special test dewar (7) through a DC power supply (9), and obtain the internal infrared focal plane temperature;

[0011] c. When the temperature of the infrared focal plane reaches 77K and stabilizes, check whether the communication of each part of the computer (1) is normal, whether the signal acquisition of the data acquisition and timing control circuit (4) is normal, whether the output signal waveform acquired by the oscilloscope (11) is normal, and whether the image acquired by the test software is normal;

[0012] d. If all functions are normal, set the integration time to 300 μs on the test software of the computer (1), set the infrared focal plane working point, continuously collect images and save them in the computer (1), and start the irradiation test;

[0013] e. After irradiation reaches a preset test dose point, stop irradiation;

[0014] f. When performing a dark field test, a dark field image with an integration time of 1 μs to 10000 μs is collected and saved in a computer (1);

[0015] g. When performing a light field test, a black body providing an infrared light source is placed in front of a special test Dewar flask (7), and a light field image with an integration time of 1 μs to 10,000 μs is collected and stored in a computer (1);

[0016] h. Continue the irradiation test, repeat steps e to g, until the predetermined maximum irradiation dose is reached, stop irradiation, and end the irradiation test;

[0017] i. Using the existing parameter calculation method, combined with the images collected in steps d, f and g, calculate the dark current, output signal, dark current noise, response rate, detection rate and defective pixels.

[0018] The present invention discloses an online low-temperature irradiation test method based on the total dose effect of infrared focal plane ionization. The advancement of the test device involved in the method is mainly reflected in:

[0019] (1) Realize the low temperature irradiation test of total ionizing dose effect:

[0020] By establishing this test device, the low-temperature irradiation test of the total ionization dose effect of γ-rays in the infrared focal plane is realized, which provides a guarantee for the online low-temperature irradiation test test conditions of the total ionization dose effect of the infrared focal plane.

[0021] (2) Realize online irradiation test:

[0022] The test device can realize online acquisition and storage of infrared focal plane imaging images during the gamma ray irradiation test, and obtain the changes in the performance parameters of the infrared focal plane during the irradiation test.

[0023] (3) Off-site irradiation test:

[0024] At present, the performance parameter test of infrared focal plane mainly adopts integrated test machine, which is large in size, heavy and cannot be moved. Since the radiation sources required for irradiation test are distributed all over the country, and if the irradiation test is not tested immediately after completion, the temperature change will affect the accuracy and reliability of the test results, therefore, the integrated test machine does not meet the requirements of infrared focal plane ionizing total dose effect irradiation test.

[0025] This test device is composed of different equipment, with the characteristics of small size, light weight, and portability. It can realize the off-site infrared focal plane performance parameter test and meet the requirements of the infrared focal plane ionizing total dose effect irradiation test. The present invention realizes the low-temperature online irradiation test of the infrared focal plane, with high reliability, simple device connection, convenient operation, and simple and easy method.

[0026] The present invention provides an online low-temperature irradiation test method based on the total dose effect of infrared focal plane ionization, wherein:

[0027] (1) Dark current calculation method:

[0028] The dark current test mainly tests the relationship between the chip response and the exposure time. Under specified conditions, by changing the integration time of the device, the output signal under the corresponding integration time is tested, and then the integration time is used as the horizontal axis and the output signal is used as the vertical axis. A scatter plot is given by the test data, and a straight line is fitted by the least squares method. The slope of the straight line is the dark signal per unit time of the device, that is, the dark current.

[0029] (2) Output signal calculation method:

[0030] A / D conversion coefficient (16bit): 4000mV / 2^16=0.061mV / DN;

[0031] Under constant blackbody irradiation conditions, the output grayscale value of the infrared focal plane is multiplied by the A / D conversion coefficient to obtain the output signal.

[0032] (3) Dark current noise calculation method:

[0033] Under dark field conditions, a fixed integration time is set and N frames of dark field grayscale images are taken. The average grayscale value of each pixel position is calculated to obtain an image composed of the average grayscale value of each pixel position; multiple integration times are set, and N frames of dark field grayscale images are taken at each integration time to obtain the dark field average grayscale image under multiple integration time conditions. The average grayscale value at each pixel position has a corresponding relationship with the integration time, and the slope of the curve is the dark current value at the pixel position, and an image composed of the dark current values ​​of each pixel is obtained; the variance of each pixel position of the dark current image is calculated, which is the dark current non-uniformity.

[0034] (4) Pixel response rate calculation method:

[0035] Under certain frame period or line period conditions, the output signal voltage generated by each pixel of the infrared focal plane array device for each unit irradiation power;

[0036] Note: The response rate can also be expressed in other ways, such as energy response rate, current response rate, charge response rate, etc. Unless otherwise specified, the response rate of the infrared focal plane array device refers to the voltage response rate;

[0037]

[0038] Where:

[0039] R(i,j)——Pixel response rate of the pixel in the i-th row and j-th column, V / W;

[0040] V S (i,j)——the response voltage of the pixel in the i-th row and j-th column corresponding to the radiation power P, V;

[0041] P is the radiation power received by the pixel in the i-th row and j-th column, W.

[0042] When a double-sided black body is used as the light source, the corresponding black body irradiation power P is calculated according to formula (2):

[0043]

[0044] Where:

[0045] P——radiant power of surface source blackbody, W;

[0046] σ——Stefan-Boltzmann constant 5.67032×10 -12 W cm -2 ·K -4 ;

[0047] ε 2 ——Effective emissivity of high-temperature surface source blackbody;

[0048] T 2 ——high temperature surface source blackbody temperature, K;

[0049] ε 1 ——Effective emissivity of low-temperature surface source blackbody;

[0050] T 1 ——low temperature surface source blackbody temperature, K;

[0051] FOV——field of view of infrared focal plane array, sr;

[0052] A D ——Pixel area, cm 2 ;

[0053] (5) Pixel detection rate calculation method:

[0054] When 1W irradiation is projected onto an area of ​​1cm 2The signal-to-noise ratio obtained in a 1 Hz bandwidth on the pixel is the ratio of the pixel response rate of the infrared focal plane array device to the noise voltage, and is converted to the square root of the product of unit bandwidth and unit pixel area; formula (3):

[0055]

[0056] Where:

[0057] D * (i,j)——Pixel detection rate of infrared focal plane array, cm·Hz 1 / 2 ·W -1 ;

[0058] A D ——Pixel area, cm 2 ;

[0059] t int ——integration time, s;

[0060] (6) Defective pixel calculation method:

[0061] Defective pixels include dead pixels and overheated pixels;

[0062] Dead pixel: A pixel with a small pixel response rate. Pixels with a pixel response rate less than 1 / 2 of the average response rate are listed as dead pixels.

[0063] Overheated pixels: pixels with large pixel noise voltage. Pixels with pixel noise voltage greater than twice the average noise voltage are listed as overheated pixels.

[0064] The online low-temperature irradiation test method based on the total ionization dose effect of the infrared focal plane described in the present invention is applicable to any infrared focal plane and is suitable for use by device development units, scientific research institutes and aerospace payload units that need to grasp the irradiation performance of the infrared focal plane in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic diagram of the composition of the online low-temperature irradiation test device for the total dose effect of infrared focal plane ionization;

[0066] Figure 2 Online image acquisition for dark field testing;

[0067] Figure 3 Online image collection for light field testing;

[0068] Figure 4 It is the output signal waveform. DETAILED DESCRIPTION

[0069] Example

[0070] The test device involved in the method is composed of a test hall and an irradiation hall. A computer 1, a low-noise DC power supply 2, a GPIB to USB connection line 3, a camlink data line 5, a first wire 6, a second wire 10, an oscilloscope 11 and a coaxial cable 12 are arranged in the test hall; a data acquisition and timing control circuit 4, a special test Dewar bottle 7, a CDBA-25Z cable 8, a ray shielding device 13 and an irradiation source are arranged in the irradiation hall. The computer 1 and the low-noise DC power supply 2 are connected through the GPIB to USB connection line 3, and the computer 1 and the data acquisition and timing control circuit 4 are connected through the camli nk data line 5, the low noise DC power supply 2 and the data acquisition and timing control circuit 4 are connected through the first wire 6, the data acquisition and timing control circuit 4 and the special test Dewar flask 7 are connected through the CDBA-25Z cable 8, the special test Dewar flask 7 and the DC power supply 9 are connected through the second wire 10, the special test Dewar flask 7 and the oscilloscope 11 are connected through the coaxial cable 12, a radiation shielding device 13 is arranged around the data acquisition and timing control circuit 4, the computer 1 is equipped with the test software, the image acquisition card and the Labview program for setting and controlling the DC power supply output, and the specific operation is carried out according to the following steps:

[0071] a. To test the dark field characteristics of the infrared focal plane, a cold shield needs to be placed in the Dewar flask; to test the light field characteristics of the infrared focal plane, a cold shield does not need to be placed in the Dewar flask. Before the irradiation test begins, a molecular pump is used to exhaust the dedicated test Dewar flask 7 encapsulating the infrared focal plane, and the flask is filled with liquid nitrogen for cooling;

[0072] b. According to the preset irradiation dose rate, the distance between the special test dewar 7 and the irradiation source is calculated, the special test dewar 7 is placed, liquid nitrogen is filled into the special test dewar 7, and the PT100 resistance value in the special test dewar 7 is measured by the DC power supply 9 to obtain the internal infrared focal plane temperature;

[0073] c. When the infrared focal plane temperature reaches 77K and stabilizes, check whether the communication between the computer 1 and each part is normal, whether the signal acquisition of the data acquisition and timing control circuit 4 is normal, whether the output signal waveform acquired by the oscilloscope 11 is normal, and whether the image acquired by the test software is normal;

[0074] d. If all functions are normal, set the integration time to 300 μs on the test software of computer 1, set the infrared focal plane working point, continuously collect images and save them in computer 1, and start the irradiation test;

[0075] e. After irradiating to a preset test dose point of 30krad (Si), stop irradiation;

[0076] f. When performing a dark field test, collect dark field images with an integration time of 1 μs-10000 μs and save them in computer 1;

[0077] g. When performing the light field test, a black body providing an infrared light source is placed in front of a special test Dewar flask 7, and a light field image with an integration time of 1 μs-10000 μs is collected and stored in a computer 1;

[0078] h. Continue the irradiation test, repeat steps e to g, until the predetermined maximum irradiation dose of 50 krad (Si) is reached, stop irradiation, and end the irradiation test;

[0079] i. Using the existing parameter calculation method, the dark current, output signal, dark current noise, response rate, detection rate and defective pixels are calculated in combination with the images collected in step d, step f and step g. The calculation methods of each parameter are as follows:

[0080] Dark current calculation method:

[0081] The dark current test mainly tests the relationship between the chip response and the integration time. Under specified conditions, by changing the integration time of the device, the output signal under the corresponding integration time is tested, and then a scatter plot is given by the test data with the integration time as the horizontal axis and the output signal as the vertical axis. A straight line is fitted by the least squares method. The slope of the straight line is the dark signal per unit time of the device, that is, the dark current;

[0082] Output signal calculation method:

[0083] A / D conversion coefficient (16bit): 4000mV / 2-16=0.061mV / DN;

[0084] Under constant blackbody irradiation conditions, the pixel output grayscale value is multiplied by the A / D conversion coefficient to obtain the output signal.

[0085] Dark current noise calculation method:

[0086] Under dark field conditions, a fixed integration time is set and N frames of dark field grayscale images are taken. The average grayscale value of each pixel position is calculated to obtain an image composed of the average grayscale value of each pixel position; multiple integration times are set, and N frames of dark field grayscale images are taken at each integration time to obtain the dark field average grayscale image under multiple integration time conditions. Then, there is a corresponding relationship between the average grayscale value at each pixel position and the integration time. The slope of the curve is the dark current value at the pixel position, and an image composed of the dark current values ​​of each pixel is obtained; the variance of each pixel position of the dark current image is calculated, which is the dark current non-uniformity;

[0087] Pixel response rate calculation method:

[0088] Under certain frame period or line period conditions, the output signal voltage generated by each pixel of the infrared focal plane array device for each unit irradiation power;

[0089] Note: The response rate can also be expressed in other ways such as energy response rate, current response rate, charge response rate, etc. Unless otherwise specified, the response rate of the infrared focal plane array device refers to the voltage response rate; Formula (1):

[0090]

[0091] Where:

[0092] R(i,j)——Pixel response rate of the pixel in the i-th row and j-th column, V / W;

[0093] V S (i,j)——the response voltage of the pixel in the i-th row and j-th column corresponding to the radiation power P, V;

[0094] P——The irradiance power received by the pixel in the i-th row and j-th column, W;

[0095] When a double-sided black body is used as the light source, the corresponding black body irradiation power P can be calculated according to formula (2):

[0096]

[0097] Where:

[0098] P——radiant power of surface source blackbody, W;

[0099] σ——Stefan-Boltzmann constant 5.67032×10 -12 W cm -2 ·K -4 ;

[0100] ε 2 ——Effective emissivity of high-temperature surface source blackbody;

[0101] T 2 ——high temperature surface source blackbody temperature, K;

[0102] ε 1 ——Effective emissivity of low-temperature surface blackbody;

[0103] T 1 ——low temperature surface source blackbody temperature, K;

[0104] FOV——field of view of infrared focal plane array, sr;

[0105] A D ——Pixel area, cm 2 ;

[0106] Pixel detection rate calculation method:

[0107] When 1W irradiation is projected onto an area of ​​1cm 2 The signal-to-noise ratio obtained in a 1 Hz bandwidth on the pixel. That is, the ratio of the pixel response rate of the infrared focal plane array device to the noise voltage, and converted to the square root of the product of unit bandwidth and unit pixel area; formula (3):

[0108]

[0109] Where:

[0110] D * (i,j)——Pixel detection rate of infrared focal plane array, cm·Hz 1 / 2 ·W -1 ;

[0111] A D ——Pixel area, cm 2 ;

[0112] ti nt ——integration time, s;

[0113] Defective pixel calculation method:

[0114] Defective pixels include dead pixels and overheated pixels;

[0115] Dead pixels: pixels with low pixel response rates. Pixels with pixel response rates less than 1 / 2 of the average response rate are classified as dead pixels.

[0116] Overheated pixels: pixels with large pixel noise voltage. Pixels with pixel noise voltage greater than 2 times the average noise voltage are classified as overheated pixels.

[0117] The test results of each parameter are shown in Table 1:

[0118] Table 1 Test results of various parameters

[0119]

[0120]

[0121] The total ionization dose effect of electronic components was studied using 60The Coγ-ray irradiation source conducts ground simulation irradiation tests. Unlike high-energy particles such as protons, when the γ-ray irradiation source starts the irradiation test, all objects inside the irradiation hall are irradiated by γ-rays; when the infrared focal plane performance parameter test is carried out, the data acquisition and timing control circuits are required to control the bias and timing of the device. The data acquisition and timing control circuits are composed of various semiconductor components and are very sensitive to radiation. The radiation damage caused by radiation will make the circuit function invalid, and thus the infrared focal plane performance parameter test cannot be completed. At the same time, since the output signal of the infrared focal plane is weak and easily interfered, thus affecting the integrity of the output signal, the connection between the data acquisition and timing control circuit and the infrared focal plane should be as short as possible, which will cause the data acquisition and timing control circuit to be placed in the radiation environment of the irradiation hall, and the radiation safety of the data acquisition and timing control circuit must be considered. Therefore, in the process of carrying out the infrared focal plane ionization total dose effect irradiation test, the infrared focal plane must be kept in a low temperature environment. At the same time, in order to obtain the degradation law of the performance parameters of the infrared focal plane during the irradiation process, the long-distance online testing technology must be solved, and the radiation safety of the data acquisition and timing control circuit must be guaranteed. Currently, none of the existing radiation sources meet the above-mentioned test conditions, and it is impossible to carry out research on the total dose effect of infrared focal plane ionization.

[0122] The present invention relates to an online low-temperature irradiation test method based on the total ionization dose effect of the infrared focal plane. The low-temperature irradiation test device and the ray shielding device used in the method can not only meet the total ionization dose irradiation test, but also ensure that the infrared focal plane maintains a low-temperature working state during the irradiation test, and the data acquisition and timing control circuit will not be irradiated by rays. At the same time, the image data of the infrared focal plane sent by the Camerlink data line and the infrared focal plane output signal waveform can be transmitted online to a control computer 30 meters away during the irradiation test. At the same time, the device has the characteristics of small size, light weight, and portability, and is suitable for carrying to a remote location to carry out irradiation test research. The image collected in the embodiment has a high image transmission quality, and the resolution meets the requirements for judging the total ionization dose effect test. The present invention has high reliability, fast data transmission speed, simple device connection, convenient operation, and simple and easy method.

Claims

1. An online low-temperature irradiation test method based on the total dose effect of infrared focal plane ionization, characterized in that: The test device involved in the method is composed of a test hall and an irradiation hall. The test hall is provided with a computer (1), a low-noise DC power supply (2), a GPIB to USB connection line (3), a camlink data line (5), a first wire (6), a second wire (10), an oscilloscope (11) and a coaxial cable (12); the irradiation hall is provided with a data acquisition and timing control circuit (4), a special test dewar flask (7), a CDBA-25Z cable (8), a ray shielding device (13) and an irradiation source. The computer (1) and the low-noise DC power supply (2) are connected via a GPIB to USB connection line (3). The computer (1) The data acquisition and timing control circuit (4) is connected via a camlink data line (5), the low-noise DC power supply (2) is connected to the data acquisition and timing control circuit (4) via a first wire (6), the data acquisition and timing control circuit (4) is connected to a dedicated test dewar flask (7) via a CDBA-25Z cable (8), the dedicated test dewar flask (7) is connected to the DC power supply (9) via a second wire (10), the dedicated test dewar flask (7) is connected to an oscilloscope (11) via a coaxial cable (12), and a radiation shielding device (13) is provided around the data acquisition and timing control circuit (4). The specific operation is performed according to the following steps: a. To test the dark field characteristics of the infrared focal plane, a cold shield needs to be placed in the Dewar flask; to test the light field characteristics of the infrared focal plane, a cold shield does not need to be placed in the Dewar flask. Before the irradiation test begins, a molecular pump is used to exhaust the dedicated test Dewar flask (7) encapsulating the infrared focal plane, and the flask is filled with liquid nitrogen for cooling. b. Calculate the distance between the special test dewar (7) and the radiation source for a preset irradiation dose rate, place the special test dewar (7), fill the special test dewar (7) with liquid nitrogen, measure the PT100 resistance value in the special test dewar (7) through a DC power supply (9), and obtain the internal infrared focal plane temperature; c. When the infrared focal plane temperature reaches 77K and stabilizes, check whether the communication of each part of the computer (1) is normal, whether the signal acquisition of the data acquisition and timing control circuit (4) is normal, whether the output signal waveform acquired by the oscilloscope (11) is normal, and whether the image acquired by the test software is normal; d. If all functions are normal, set the integration time to 300 µs on the test software of the computer (1), set the infrared focal plane working point, continuously collect images and save them in the computer (1), and start the irradiation test; e. After irradiation reaches a preset test dose point, stop irradiation; f. When performing a dark field test, collect dark field images with an integration time of 1 μs-10000 μs and save them in a computer (1); g. When performing a light field test, a black body providing an infrared light source is placed in front of a special test Dewar flask (7), and a light field image with an integration time of 1 μs to 10,000 μs is collected and stored in a computer (1); h. Continue the irradiation test, repeat steps e to g, until the predetermined maximum irradiation dose is reached, stop irradiation, and end the irradiation test; i. Using the existing parameter calculation method, combined with the images collected in steps d, f and g, calculate the dark current, output signal, dark current noise, response rate, detection rate and defective pixels.

Images