A method for system-level total dose effect testing

Abstract

The application relates to a method for system-level total dose effect test, which is used for solving the problem that the system radiation resistance performance is difficult to be accurately evaluated in the existing system-level total dose effect test process. The specific steps of the application are as follows: step 1, placing a test system on a rotating unit in an irradiation room; step 2, calibrating and recording the front end, rear end and rear end dose rate of 180 degrees of the test system by using a dose rate calibration device; step 3, irradiating according to the dose rate calibration result of step 2; step 4, segmenting the total dose, and obtaining the total dose D' total ; step 5, calculating the first irradiation time point t'1, the second irradiation time t'2 and the total irradiation time t' of each dose segment; and step 6, combining the calculation results of steps 4 and 5, and irradiating to n segments to complete the irradiation or irradiating the test system to the target total dose value. The test steps of the application are simple and easy to operate.​​

Description

TECHNICAL FIELD

[0001] The present application relates to a method for evaluating the radiation resistance of an electronic system, in particular to a method for system-level total dose effect test. BACKGROUND

[0002] With the development of space technology, the difference between the device-level anti-ionizing total dose radiation capability and the system-level anti-ionizing total dose radiation capability is gradually concerned. The inequality between the device-level radiation resistance performance and the system-level radiation resistance capability, the coupling between the device radiation effect parameters, and other factors make the demand for system-level total dose effect test gradually increase.

[0003] 60 Co gamma rays are commonly used radiation sources for ground simulation tests of space electronic systems, which have strong penetration ability. Unlike device-level total dose effect tests, the key point of system-level total dose effect tests is to ensure that the total dose accumulated by each electronic component in the system at the same time during irradiation is equivalent. However, the spatial size of the system and the shielding of internal components will inevitably cause differences in the dose rate experienced by electronic components inside the system. Therefore, when conducting system-level total dose effect tests, this problem must be considered. Unreasonable test methods will inevitably result in large differences in the total dose accumulated by electronic components at different positions inside the system during irradiation, making it difficult to accurately evaluate the system's anti-total dose radiation capability.

[0004] Existing system-level total dose effect test methods include:

[0005] ① Minimum satisfaction method: After calibrating the dose rate difference before and after the test system, the electronic components on the PCB at the farthest position from the radiation source in the test system accumulate the specified total dose, and it is considered that the system can meet the target total dose requirement.

[0006] ② Intermediate time point rotation method: The center position of the test system is at the specified dose rate position, and when the accumulated dose reaches half of the specified dose, the test system is rotated before and after irradiation, and the accumulated dose reaches the specified dose.

[0007] However, the first minimum satisfaction method has the following problems: due to the shielding effect of internal components, the actual total dose experienced by the electronic components at the front end of the system will be much larger than expected, resulting in an over-conservative estimate of the test system. The second intermediate time point rotation method has the following disadvantages: it does not consider the effect of system shielding on the attenuation of radiation, which may overestimate the anti-total dose capability of the test system. In addition, when using this method, the dose rate at the front and rear ends of the test system will exceed the value specified in the specification or standard, resulting in the existence of uncontrollable dose rate effects.

[0008] Therefore, it is urgent to propose a system-level total dose effect test method to solve the problems faced in the system-level total dose effect test. SUMMARY

[0009] In order to more scientifically and accurately evaluate the total dose resistance of the system, solve the problem that the anti-radiation performance of the system is difficult to accurately evaluate due to the shielding of the system space size and the devices in the system in the system-level total dose effect test process, the application provides a method for system-level total dose effect test.

[0010] To achieve the above-mentioned purpose, the application realizes the following technical scheme:

[0011] A method for system-level total dose effect test, which is characterized in that the specific steps are as follows:

[0012] Step 1, the rotating unit and the radioactive source are placed in the irradiation room, and the irradiation rotating unit is located in the irradiation range of the radioactive source;

[0013] The control unit is placed outside the irradiation room and connected with the rotating unit through a cable;

[0014] The test system is placed on the rotating unit in the irradiation room;

[0015] Step 2, the dose rate calibration device is used to calibrate and record the dose rate of the front end, the rear end and the rear end rotated by 180 degrees of the test system;

[0016] Step 3, according to the dose rate calibration result of step 2, the test system is rotated by 180 degrees after the first irradiation, the second irradiation is continued, and the total irradiation time t is obtained;

[0017] Step 4, the cumulative total dose of the test system is segmented into n parts to form n dose segments, at this time the segmented total dose borne by each dose segment is D' total ;

[0018] Step 5, the first irradiation time t'1, the second irradiation time t'2 and the total irradiation time t' of each dose segment are calculated;

[0019] Step 6, combining the calculation results of step 4 and step 5, the test system is rotated by 180 degrees at the rotation time of the rotating unit in each dose segment and the end time of the segmented dose point during the irradiation process, and the irradiation is continued until the n segments complete the irradiation, and the irradiation is stopped.

[0020] Further, in step 1, the test system is placed on the rotating unit in the irradiation room, which is specifically:

[0021] According to the internal PCB layout of the test system, the PCB in the test system is irradiated perpendicularly to the irradiation direction of the radiation source, and the test system is placed to ensure that the dose rate at the front end of the test system is the specified dose rate value.

[0022] Further, the step 2 is specifically:

[0023] During the calibration, different points on the same surface are selected for calibration according to the actual size of the system to be tested, and the minimum value or the average value is selected as the dose rate value of the panel according to the final calibration result. The dose rate at the front end is the specified dose rate value, denoted as R, the dose rate at the rear end is denoted as R1, and the dose rate at the rear end after rotation is denoted as R2.

[0024] Further, in step 3, the calculation method of the first irradiation time, the second irradiation time and the total irradiation time t is as follows:

[0025] The cumulative total dose D of the system at the front end during irradiation total_front :

[0026] D total_front = R * t1 + R2 * t2

[0027] The cumulative total dose D of the system at the rear end during irradiation total_back :

[0028] D total_back = R1 * t1 + R * t2

[0029] The first irradiation time t1 and the second irradiation time t2 after turning 108° are respectively:

[0030]

[0031]

[0032] Then the total irradiation time is: t = t1 + t2

[0033] Wherein: t1 is the first irradiation time, t2 is the second irradiation time after rotating 180°, D total_front and D total_back are equal, and both are equal to the target cumulative total dose D total of the test system.

[0034] Further, in step 4, the calculation formula of the cumulative total dose of the test system is divided into n segments, and each dose segment bears a segmented total dose of D′ total :

[0035]

[0036]

[0037] Furthermore, in step 5, the specific calculation formulas for the first irradiation time t′1, the second irradiation time t′2, and the total irradiation time t′ for each dose segment are as follows:

[0038]

[0039]

[0040] t′=t′1+t′2.

[0041] The beneficial effects of this invention are:

[0042] (1) This invention provides a specific implementation method for a system-level total dose effect test, which can more scientifically and accurately give the system's total dose resistance capability, and provide strong data support for the application of electronic systems in radiation environments and the evaluation of their radiation resistance performance.

[0043] (2) The combination of the rotating platform and the test method provided by the present invention can effectively solve the time required for system rotation in the total dose effect test process, avoid the problem of frequent raising and lowering of the source during the test, greatly reduce the complexity of the total dose effect test, and reduce the manpower cost consumption in the system test process.

[0044] (3) The system-level total dose effect test method provided by the present invention can effectively solve the technical problems in the evaluation of system total dose effect. The method is scientific and effective, and greatly reduces the cost of system total dose effect test. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the overall structure of the total dose testing device of the present invention;

[0046] Figure 2 This is a flowchart illustrating the implementation of the total dose testing method for the system of the present invention;

[0047] Figure 3 This is a schematic diagram showing the distribution of rotation time points during the total dose test of the system of the present invention.

[0048] The specific reference numerals in the attached figures are as follows:

[0049] 1-Control unit, 2-Rotation unit, 3-Irradiation room, 4-Radiation source. Detailed Implementation

[0050] To make the present invention clearer, the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0051] Because radiation irradiation devices involve strong radiation fields, the rotation system and source raising / lowering processes during irradiation are quite complex. This invention provides a system-level total dose testing device, including a control unit 1 and a rotation unit 2. The rotation unit 2 is located inside the irradiation chamber 3 and is driven by a magneto. It is a passive component with strong radiation resistance. The control unit 1 is located outside the irradiation chamber 3, has strong radiation resistance, and is connected to the rotation unit 2 via cables to control its rotation. A radiation source 4 is installed inside the irradiation chamber 3 to release radiation onto the test system placed on the rotation unit 2.

[0052] During use, the device places the test system on the rotating unit 2 inside the irradiation chamber 3. The control system 1 outside the irradiation chamber 3 controls the rotating unit 2 to achieve automatic rotation of the test system without the need for additional lifting source operation or manual entry into the rotation operation.

[0053] Based on the above-described apparatus, a method for system-level total dose effect testing is as follows:

[0054] Step 1, subject system placement

[0055] According to the internal PCB layout of the test system, when the test system is placed in the irradiation room 3, the PCB board in the test system is irradiated perpendicular to the radiation source 4. At the same time, when the test system is placed, the dose rate at the front end of the test system should be ensured to be the dose rate value specified in the test. The front end of the test system is the position where the test system is closest to the radiation source 4.

[0056] Step 2: Perform dose rate calibration

[0057] After placing the test system on the rotating unit 2, the dose rate at the front end, rear end, and rear end after 180° rotation was calibrated and recorded using a dose rate calibration device. During the calibration process, different points were selected on the same surface for calibration based on the actual size of the system under test. The minimum or average value was selected as the dose rate value of the panel based on the final calibration results. The dose rate at the front end was recorded as the specified dose rate value, denoted as R, the calibrated dose rate at the rear end was recorded as R1, and the dose rate at the rear end after rotation was recorded as R2.

[0058] Step 3, Determining the total irradiation time

[0059] Based on the dose rate calibration results in step 2, the system should be switched before and after irradiation at the irradiation time point.

[0060] The calculation methods for the first irradiation time, the second irradiation time, and the total irradiation time are as follows:

[0061] The cumulative total dose D at the front end of the test system during irradiation total_front It can be represented as:

[0062] Dtotal_front =R*t1+R2*t2 (1)

[0063] The cumulative total dose D in the later part of the test system during irradiation total_back It can be represented as:

[0064] D total_back =R1*t1+R*t2 (2)

[0065] In the formula, t1 is the first irradiation time, t2 is the second irradiation time after rotating 180°, and D total_front With D total_back Equal to the target cumulative total dose D of the test system. total Combining Equations 1 and 2, we can see that the first irradiation time t1 before the flip and the second irradiation time t2 after the flip are respectively Equations 3 and 4:

[0066]

[0067]

[0068] The total irradiation time is t = t1 + t2.

[0069] Step 4, Total Dose Segmentation

[0070] To ensure that the total dose differences experienced by each device in the test system are more similar during irradiation, and to more accurately reflect the state of the electronic system in the space radiation environment, the total dose difference experienced by each device in the system should be kept to less than 10%. Therefore, the test system can be irradiated in segments. The cumulative total dose of the test system can be divided into n segments, as shown in Equation 5. In this case, the total dose experienced by each dose segment is D′. total The calculation method is shown in Equation 6:

[0071]

[0072]

[0073] Step 5: Calculate the first irradiation time t′1, the first irradiation time t′2, and the total irradiation time t′ for each dose segment.

[0074] D′ total Substituting into step 3, calculate the first irradiation time t′1, the second irradiation time t′2, and the total irradiation time t′ of the dose segment. The calculation results are shown in equations 7, 8, and 9:

[0075]

[0076]

[0077] t′=t′1+t′2 (9)

[0078] Step 6: Combining the calculation results from Steps 4 and 5, during the irradiation process, the test system is rotated 180° at the first and second irradiation times of each dose segment using a rotating device. The distribution of rotation time points is shown in the figure below. Figure 3 As shown. Continue irradiation until the cumulative total dose reaches the target total dose value or the system achieves radiation resistance, then stop irradiation.

[0079] The above description is merely a specific example of the present invention and does not constitute any limitation on the present invention. After understanding the content and principle of the present invention, various modifications and changes in form and detail may be made without departing from the principle of the present invention. However, these modifications and changes based on the concept of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A method for system-level total dose effect testing, characterized in that, The specific steps are as follows: Step 1: Place the rotating unit (2) and the radiation source (4) inside the irradiation chamber (3), and irradiate the rotating unit (2) within the irradiation range of the radiation source (4); The control unit (1) is placed outside the irradiation chamber (3) and connected to the rotating unit (2) via a cable; The test system was placed on the rotating unit (2) inside the irradiation chamber (3); According to the internal PCB layout of the test system, the PCB in the test system is irradiated perpendicular to the radiation source (4) and at the same time, when the test system is placed, the dose rate at the front end of the test system should be guaranteed to be the dose rate value specified in the test. Step 2: Use a dose rate calibration device to calibrate and record the dose rates at the front end, rear end, and rear end rotated 180° of the test system. During the calibration process, different points are selected on the same surface for calibration according to the actual size of the system under test. The minimum or average value is selected as the dose rate value of the surface based on the final calibration result. The front-end dose rate is the specified dose rate value and is recorded as R. The rear-end dose rate calibration value is recorded as R1. The rear-end dose rate after rotation is recorded as R2. Step 3: Based on the dose rate calibration results in Step 2, rotate the test system 180° after the first irradiation and continue the second irradiation, and obtain the total irradiation time t. Step 4: Divide the cumulative total dose of the subject's system into n segments, forming n dose segments. At this point, the total dose received by each dose segment is D'. total ; Step 5: Calculate the first irradiation time t'1, the second irradiation time t'2, and the total irradiation time t' for each dose segment; Step 6: Combining the calculation results of Step 4 and Step 5, the test system is rotated 180° by the rotating unit (2) at the rotation time and the end time of the dose point in each dose segment during the irradiation process, and irradiation continues until n segments are irradiated and then irradiation is stopped.

2. The method for system-level total dose effect testing according to claim 1, characterized in that, In step 3, the calculation methods for the first irradiation time, the second irradiation time, and the total irradiation time t are as follows: The cumulative total dose D at the front end of the system during irradiation total_front : D total_front =R*t1+R2*t2 The cumulative total dose D at the back end of the system during irradiation total_back : D total_back =R1*t1+R*t2 The first irradiation time t1 and the second irradiation time t2 after the 108° flip are respectively: The total irradiation time is: t = t1 + t2 Where: t1 is the first irradiation time, t2 is the second irradiation time after rotating 180°, and D total_front With D total_back Equal to the target cumulative total dose D of the test system. total .

3. The method for system-level total dose effect testing according to claim 2, characterized in that, In step 4, the number of cumulative total dose segments n of the test system and the total dose received by each segment are D'. total The calculation formula is:

4. The method for system-level total dose effect testing according to claim 3, characterized in that, In step 5, the specific calculation formulas for the first irradiation time t'1, the second irradiation time t'2, and the total irradiation time t' of each dose segment are as follows: t' = t'1 + t'2.

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