CN116625640A - On-line testing method and system for irradiation under-plane array CCD - Google Patents

Abstract

The invention relates to a radiation effect test system and method, in particular to an on-line test method and test system for an irradiation lower array CCD, which solves the technical problems that the working condition of the area array CCD cannot be fed back on line in real time and the real-time change rule of performance parameters in the irradiation process can not be realized when an area array CCD radiation damage effect ground simulation experiment is carried out. The method for testing the CCD of the irradiation lower array on line can solve the problem of complicated test when carrying out the ground simulation experiment of the CCD radiation damage effect, improves the experimental efficiency, and can acquire the performance parameters of the CCD of the area array in the irradiation process; a CCD driving circuit is arranged on the radiation plate; the radiation source and the light source are arranged on an emergent light path, a CCD device to be irradiated is arranged on the emergent light path, and a CCD driving circuit is connected with the CCD device to be irradiated.

Description

An online test method and test system for array CCD under irradiation

technical field

The invention relates to a radiation effect test system and method, in particular to an on-line test method and test system for irradiating a CCD array below.

Background technique

A charge-coupled device (CCD) generates charges by light injection or electron injection, stores charges by biasing the gate of the device, and uses the principle of depletion layer coupling with the output amplifier to carry out charges. Photoelectric image sensors for transmission and output have the advantages of small size, light weight, low power consumption, high quantum efficiency, high image resolution, and wide dynamic range, and are widely used in aerospace exploration, space scanning, and satellite observation. However, due to the particularity of the space environment, when the CCD is used in an orbiting satellite or an aerospace imaging system, the CCD will have performance degradation or even functional failure caused by radiation damage. Radiation damage effects of CCD generally include total dose effect, displacement effect and single event transient effect.

High-energy particles in the space environment, such as protons, electrons, and heavy ions, will induce radiation damage to CCDs, leading to degradation of CCD performance parameters, which will affect the normal operation of CCDs and even damage the internal structure of CCDs. Therefore, it is of great significance to carry out the ground simulation experiment of CCD radiation damage effect to study the mechanism of CCD radiation damage and the design of CCD anti-radiation reinforcement. When conducting ground simulation experiments on CCDs, due to the large size of the current test system, the post-irradiation tests of CCDs are all offline tests, that is, the CCD under test needs to be taken out after the radiation dose has accumulated to the target dose point, and then placed again after the test is completed. Into the irradiation room for irradiation, which brings great inconvenience to the irradiation experiment and cannot obtain the real-time change law of the performance parameters during the irradiation process.

Contents of the invention

The purpose of the present invention is to solve the technical problem that the working condition of the area array CCD and the real-time change law of the performance parameters in the irradiation process cannot be fed back in real time when carrying out the ground simulation experiment of the radiation damage effect of the area array CCD, and to provide a radiation According to the online test method and test system of the array CCD, it can effectively reduce the tediousness of the existing test system and the danger of the experimenters when carrying out the ground simulation experiment of the radiation damage effect of the area array CCD, thereby improving the experimental efficiency.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

An online test method for irradiating the array CCD below, which is special in that it includes the following steps:

1) Preparation before the test

1.1. Set the CCD device to be irradiated on the exit route of the radiation source;

1.2. Set the experimental environment temperature;

1.3. Build a light source in the experimental environment, so that the photosensitive surface of the CCD device to be irradiated is located on the light exit path of the light source;

2) Test the performance parameters of the CCD device to be irradiated before irradiation

2.1. Set the integration time of the CCD device to be irradiated, turn on the light source, collect the first parameter before the irradiation of the CCD device to be irradiated N times, and save it; N is an integer greater than 1; the first parameter includes a linear saturation output and total gain;

2.2. Calculate the average value after removing the extreme values of all pixels in the first parameter collected each time, and obtain the performance parameter change curve before irradiation;

2.3. Judging whether the CCD device to be irradiated is stable according to whether the performance parameter change curve before irradiation is stable;

If the CCD device to be irradiated works stably, turn off the light source, record the light source intensity, and perform step 3);

If the CCD device to be irradiated works unstable, then adjust the integration time of the CCD device to be irradiated, and return to step 2.1;

3) Test the performance parameters under the irradiation of the CCD device to be irradiated

3.1, turn on the radiation source and the light source of equal intensity before irradiation, and collect the second parameter after the irradiation of the CCD device to be irradiated n times, and save it; n is an integer greater than 1; the second parameter includes linear saturation output and overall gain;

3.2. Calculate the average value after removing the extreme values of all pixels in the second parameter after irradiation, and obtain the performance parameter change curve of the CCD device to be irradiated after irradiation;

3.3. Judging whether the CCD device to be irradiated is damaged according to whether the performance parameter change curve after irradiation is stable;

If the CCD device to be irradiated is damaged, turn off the radiation source and the light source, mark the CCD device to be irradiated as damaged, return to step 1), and continue the follow-up work;

If the CCD device to be irradiated is not damaged, save the performance parameters of the CCD device to be irradiated after irradiation, and complete the online test of the CCD array below the irradiation.

Further, step 4) is also included:

The performance parameter change curve after irradiation is compared with the performance parameter change curve before irradiation to obtain the effect of irradiation on the performance parameters of the CCD device to be irradiated.

Further, in step 2.1, the integration time of the CCD device to be irradiated is set through the host computer.

Further, step 1.1 is specifically:

After wiping the photosensitive surface of the CCD device to be irradiated, the beam current direction of the radiation source is set to be perpendicular to the photosensitive surface of the CCD device to be irradiated.

Further, step 1.3 is specifically:

The light source is set up in the experimental environment so that the photosensitive surface of the CCD device to be irradiated is perpendicular to the outgoing light path of the light source.

Further, in step 2.3, whether the change curve of the performance parameter before irradiation is stable is specifically:

Determine whether the error between the linear saturation output parameters collected each time is ±1000DN, and whether the error between the total gain parameters collected each time is ±0.05DN/e ^- ;

In step 3.3, it is specifically as follows according to whether the performance parameter change curve after irradiation is stable:

Determine whether the error between the linear saturation output parameters collected each time is ±1000DN, and whether the error between the total gain parameters collected each time is ±0.05DN/e ^- .

Further, in step 1.2, the experimental environment temperature is 25°±5°;

In step 2.1, the value of N is 30;

In step 3.1, the value of n is 100.

At the same time, the present invention also provides an on-line test system for irradiating the lower array CCD, which is used to realize the above-mentioned online test method for irradiating the lower array CCD. , a light source, a drive controller, an irradiation panel, and an acquisition processor installed outside the irradiation room and connected to the drive controller;

A CCD drive circuit is arranged on the radiation plate;

There is a signal shielding box outside the drive controller

The radiation source and the outgoing optical path of the light source are used to set the CCD device to be irradiated, and the CCD drive circuit is connected to the CCD device to be irradiated;

The drive controller includes A/D conversion module and FPGA main control module;

The FPGA main control module is respectively connected with the CCD drive circuit, the A/D conversion module and the acquisition processor;

The A/D conversion module is connected with the CCD device to be irradiated;

The A/D conversion module is used to perform double-sampling processing on the original CCD analog signal of the CCD device to be irradiated, and convert the original CCD analog signal into a digital signal, which is sent to the FPGA main control module;

The FPGA main control module is used to generate timing driving signals that meet the voltage requirements of the CCD device to be irradiated, and transmit the digital signals to the acquisition processor;

The CCD drive circuit is used to convert the timing drive signal into a CCD drive signal, and then drive the CCD device to be irradiated.

Further, it also includes a light source moving motor connected to the light source for controlling the up and down position of the light source;

A CCD socket connected to the CCD driving circuit is also arranged on the radiation plate.

Further, it also includes a motion motor connected to the irradiation plate, which is used to adjust the position of the CCD device to be irradiated by driving the irradiation plate.

Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

1. The online test method of the array CCD below the irradiation of the present invention can solve the problem of complicated testing when carrying out the CCD radiation damage effect ground simulation experiment, improves the experimental efficiency, and can obtain the area array CCD performance parameters in the irradiation process, It provides experimental test technical support for the study of the radiation damage mechanism of the area array CCD and the anti-radiation reinforcement design of the area array CCD.

2. The on-line test system for irradiating the lower array CCD of the present invention adopts the sub-motherboard design method in which the irradiation board and the drive controller are separated, which can effectively reduce the influence of the radiation source on the drive controller and ensure the stable operation of the system.

3. The online test system of the array CCD under irradiation of the present invention can realize long-distance transmission and communication by setting the acquisition processor outside the irradiation room, simplifies the system connection mode, and can make the acquisition processor of the receiving data operate in a safe manner. The location avoids the influence of radiation, and through the remote control function of the acquisition processor, the experimenter can remotely operate the test system in a safe environment, reducing the frequency of the experimenter entering the irradiation room, effectively reducing the danger of the experimenter, and solving the problem of ground On-line measurement of array CCD after radiation damage simulation experiment.

4. The present invention irradiates the online test system of the lower array CCD. During the experiment, the FPGA main control module is arranged in the signal shielding box to reduce the influence of the radiation source on the signal processing and ensure the stable operation of the system.

Description of drawings

Fig. 1 is the structural representation of the online test system embodiment of array CCD below irradiation of the present invention;

Fig. 2 is the control block diagram of drive controller in the online test system embodiment of array CCD below irradiation of the present invention;

Fig. 3 is a flow chart of an embodiment of an online test method for irradiating the lower array CCD of the present invention.

The reference signs in the figure are:

1-radiation source, 2-light source, 3-light source moving motor, 4-CCD image sensor, 5-radiation plate, 51-CCD socket, 52-CCD drive circuit, 6-motion motor, 7-drive controller, 71 -A/D conversion module, 72-FPGA main control module, 8-signal shielding box, 9-flexible cable, 10-USB data cable, 11-acquisition processor.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the technical solutions in the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, an on-line test system for irradiating the lower array CCD includes a radiation source 1, a light source 2, a light source moving motor 3, an irradiating plate 5, a moving motor 6, and a drive controller 7 arranged in the irradiation room , a signal shielding box 8 and an acquisition processor 11 arranged outside the irradiation room and connected to the drive controller 7 .

As shown in Figure 2, a CCD socket 51 and a CCD drive circuit 52 are arranged on the irradiation plate 5; a signal shielding box 8 is arranged outside the drive controller 7; , and be connected with CCD drive circuit 52 by CCD socket 51; Drive controller 7 comprises A/D conversion module 71 and FPGA main control module 72; FPGA main control module 72 is connected with CCD drive circuit 52, A/D conversion module 71 and The acquisition processor 11 is connected; the A/D conversion module 71 is connected with the CCD device to be irradiated.

The radiation source 1 is used to induce radiation damage to the CCD device to be irradiated. The light source 2 provides a stable and uniform light source 2 for the CCD device to be irradiated; the light source moving motor 3 is used to control the position of the light source 2 so that the light source 2 can move up and down. The motion motor 6 is used to drive the position of the irradiation plate 5, so that the irradiation plate 5 can move up, down, left, and right. During the experiment, the CCD device to be irradiated can be installed on the CCD socket 51, and the light source 2, the radiation source 1 and the irradiation plate 5 are kept at the same horizontal position, so that the beam current of the radiation source 1 and the outgoing light of the light source 2 are irradiated vertically on the On the CCD device to be irradiated. The CCD device to be irradiated completes image acquisition under the drive of the time sequence drive signal, and outputs the original CCD analog signal; the CCD drive circuit 52 is used to convert the time sequence drive signal generated by the FPGA main control module 72 to meet the voltage requirements of the CCD device to be irradiated Timing drive signal.

The A/D conversion module 71 includes an analog signal preprocessing circuit and an analog-to-digital conversion circuit; the analog signal preprocessing circuit includes a constant current drive circuit and a filter amplifier circuit, which performs pre-filtering, signal amplification, and darkening to the original CCD analog signal input. Level clamping, denoising correlation double sampling processing, and the original CCD analog signal output by the CCD device to be irradiated is converted into a digital signal through the analog-to-digital conversion circuit in the A/D conversion module 71 and transmitted to the FPGA main control module 72 .

The FPGA main control module 72 is the core of the system of the present invention, and is used for generating the timing drive signal meeting the voltage requirements of the CCD device to be irradiated, providing the required clamping and sampling/holding pulse signals for the original CCD analog signal A/D processing, and simultaneously The image data is cached by built-in storage resources and sent to the acquisition processor 11 .

When carrying out the irradiation experiment, the drive controller 7 is set in the signal shielding box 8, and the signal shielding box 8 is used to shield the influence of the radiation source 1 on the drive controller 7, so that the drive controller 7 is set in the irradiation room to reduce the radiation. The transmission distance between the photo board 5 and the drive controller 7 ensures the stable operation of the system of the present invention. The irradiation board 5 is connected to the A/D conversion module 71 and the FPGA main control module 72 through the flexible cable 9, and the drive timing signal provided by the FPGA main control module 72 is converted by the CCD drive circuit 52 to meet the voltage requirements of the CCD device to be irradiated. The driving timing signal controls the CCD to output the original CCD analog signal and converts it into quantized digital data through the A/D conversion module 71 . The drive controller 7 transmits the collected quantized digital data to the host computer through the USB data line 10 for processing and storage.

In this embodiment, the CCD drive timing in the drive controller 7 and the clamping and sampling/holding pulse signals required for the conversion process of the A/D conversion module 71 are all implemented by the FPGA main control module 72 through the Verilog HDL hardware description language programming, The CCD drive sequence takes the external system clock source of the FPGA main control module 72 as the reference clock, uses the internal phase-locked loop to multiply the frequency, and then divides the frequency by a counter to obtain a sequence drive signal that meets the timing requirements of each channel of the CCD; A/D conversion module 71 requires the FPGA main control module 72 to provide correct register configuration data and sampling clock signals that meet the timing requirements to ensure its normal operation. The internal registers are set by the FPGA main control module 72 through the three-wire serial port to realize input clamping, modulus For the setting of functions such as conversion and related double sampling, the external system clock of the FPGA main control module 72 is used as the reference clock, and the timing signal meeting the timing requirements of each channel of the A/D conversion module 71 is obtained by frequency division by a counter.

Specifically, the CCD device to be irradiated adopts an area array CCD image sensor 4, the acquisition processor 11 selects a host computer, and the drive timing generated by the FPGA main control module 72 is driven by the timing sequence that meets the voltage requirements of the CCD image sensor 4 through the CCD drive circuit 52 module. signal, the CCD image sensor 4 outputs the original analog signal under the action of the timing drive signal, and the A/D conversion module 71 performs filtering, denoising and analog-to-digital conversion on the original analog signal, and the obtained digital data is cached in the FPGA main control module 72 In the internal storage resources of the computer, the collected digital data is transmitted to the host computer through the USB chip and interface, and the CCD performance parameters are obtained after being processed by the host computer.

As shown in Figure 3, utilize system of the present invention to carry out the on-line testing method of array CCD below irradiation, specifically comprise the following steps:

Step 1. Preparation before the test

1.1. After wiping the photosensitive surface of the CCD image sensor 4 clean, make the beam flow direction of the radiation source 1 perpendicular to the photosensitive surface of the CCD image sensor 4;

1.2. Control the temperature of the experimental environment at 25°±5°, and control the influence of the temperature on the performance parameters of the CCD image sensor 4;

1.3. Build a visible light source 2 in the irradiation room, so that the light emitted by the light source 2 can irradiate the photosensitive surface of the CCD image sensor 4, so as to ensure that the CCD image sensor 4 works under uniform illumination conditions during the test;

Step 2. Test the performance parameters of the CCD device to be irradiated before irradiation

2.1. Set the integration time of the CCD device to be irradiated through the host computer, turn on the light source 2, collect the first parameter before the irradiation of the CCD device to be irradiated 30 times, and save it. The first parameters include a linear saturation output and an overall gain;

2.2. Calculate the average value after removing the extreme values of all pixels in the first parameter collected each time, and obtain the performance parameter change curve before irradiation;

2.3. Judging whether the CCD image sensor 4 is working stably according to the performance parameter change curve before irradiation;

If the CCD device to be irradiated works stably, turn off the light source 2, record the intensity of the light source 2, and perform step 3);

If the CCD device to be irradiated works unstable, then adjust the integration time of the CCD device to be irradiated, and return to step 2.1;

Step 3. Test the performance parameters of the CCD device to be irradiated under the irradiation

3.1, turn on the radiation source 1 and the light source 2 of equal intensity before irradiation, and collect the second parameter after the irradiation of the CCD device to be irradiated 100 times, and save it; the second parameter includes linear saturation output and total gain;

3.2. Calculate the average value after removing the extreme values of all pixels in the second parameter after irradiation, and obtain the performance parameter change curve of the CCD device to be irradiated after irradiation;

3.3. Judging whether the CCD device to be irradiated is damaged according to whether the performance parameter change curve after irradiation is stable;

If the CCD device to be irradiated is damaged, turn off the radiation source 1 and light source 2, mark the CCD device to be irradiated as damaged, return to step 1), and continue the follow-up work;

If the CCD device to be irradiated is not damaged, save the performance parameters of the CCD device to be irradiated after irradiation, and complete the online test of the CCD array below the irradiation.

Step 4. Comparison

The performance parameter change curve after irradiation is compared with the performance parameter change curve before irradiation to obtain the effect of irradiation on the performance parameters of the CCD device to be irradiated.

In the embodiment of this city, in step 2.3, according to whether the performance parameter change curve before irradiation is stable or not, it is specifically: when the error between the linear saturation output parameters collected each time is ±1000DN, and the total gain parameters collected each time The error of ±0.05DN/e ^- , the performance parameter change curve before irradiation is stable. In step 3.3, according to whether the performance parameter change curve after irradiation is stable or not, it is specifically: when the error between the linear saturation output parameters collected each time is ±1000DN, and the error between the total gain parameters collected each time is ±0.05DN /e ^- , the change curve of performance parameters after irradiation.

The online testing method of the array CCD under the irradiation of the present invention can effectively reduce the cumbersomeness of testing and the danger of the experimenters when the existing testing system is carrying out the CCD image sensor 4 radiation damage effect ground irradiation simulation experiment, thereby improving the experimental efficiency, And it can obtain the radiation performance parameters of the CCD image sensor 4 in the irradiation process; at the same time, the system adopts the sub-motherboard design scheme in which the irradiation board 5 and the drive controller 7 are separated, which can effectively reduce the radiation source 1 to the drive controller 7. influence to ensure the stable operation of the system.

Claims (10)

1. An on-line testing method of an irradiation array CCD is characterized by comprising the following steps:

1) Preparation before test

1.1, arranging a CCD device to be irradiated on an emergent path of a radiation source (1);

1.2, setting the experimental environment temperature;

1.3, constructing a light source (2) in an experimental environment, and enabling a photosensitive surface of the CCD device to be irradiated to be positioned on an emergent light path of the light source (2);

2) Testing performance parameters of CCD device to be irradiated before irradiation

2.1, setting the integration time of the CCD device to be irradiated, starting a light source (2), collecting the first parameters of the CCD device to be irradiated for N times before irradiation, and storing; n is an integer greater than 1; the first parameter includes a linear saturated output and a total gain;

2.2, removing extremum of all pixels in the first parameter collected each time, and then averaging to obtain a performance parameter change curve before irradiation;

2.3, judging whether the CCD device to be irradiated works stably or not according to whether the performance parameter change curve before irradiation is stable or not;

if the CCD device to be irradiated works stably, the light source (2) is turned off, the intensity of the light source (2) is recorded, and the step 3) is executed;

if the CCD device to be irradiated works unstably, adjusting the integration time of the CCD device to be irradiated, and returning to the step 2.1;

3) Testing performance parameters of CCD device to be irradiated under irradiation

3.1, starting a radiation source (1) and a light source (2) with equal intensity before irradiation, collecting second parameters of the CCD device to be irradiated after irradiation for n times, and storing; n is an integer greater than 1; the second parameter includes a linear saturated output and a total gain;

3.2, removing extreme values of all pixels in the irradiated second parameter, and then averaging to obtain a performance parameter change curve of the irradiated CCD device;

3.3, judging whether the CCD device to be irradiated is damaged or not according to whether the performance parameter change curve after irradiation is stable or not;

if the CCD device to be irradiated is damaged, the radiation source (1) and the light source (2) are turned off, the CCD device to be irradiated is marked to be damaged, the step 1) is returned, and the subsequent work is continued;

if the CCD device to be irradiated is not damaged, the performance parameters of the CCD device to be irradiated after irradiation are stored, and the on-line test of the CCD under irradiation is completed.

2. The method for on-line testing of an illuminated area array CCD according to claim 1, further comprising step 4):

and comparing the performance parameter change curve after irradiation with the performance parameter change curve before irradiation to obtain the influence of irradiation on the performance parameters of the CCD device to be irradiated.

3. An on-line testing method for irradiating an underlying array CCD according to claim 2, wherein:

in step 2.1, the integration time of the CCD device to be irradiated is set through the upper computer.

4. An on-line testing method for irradiating an underlying array CCD according to claim 3, wherein step 1.1 specifically comprises:

after wiping the photosensitive surface of the CCD device to be irradiated, setting the beam direction of the radiation source (1) to be perpendicular to the photosensitive surface of the CCD device to be irradiated.

5. The method for on-line testing of an irradiation array CCD according to claim 4, wherein the step 1.3 is specifically:

and constructing a light source (2) in an experimental environment, so that the light sensitive surface of the CCD device to be irradiated is perpendicular to an emergent light path of the light source (2).

6. The method for on-line testing of an illuminated area array CCD according to claim 5, wherein:

in step 2.3, the step of determining whether the performance parameter change curve is stable or not according to the irradiation is specifically as follows:

judging whether the error between the linear saturated output parameters collected each time is +/-1000 DN and whether the error between the total gain parameters collected each time is +/-0.05 DN/e ^- ；

In step 3.3, the step of determining whether the performance parameter change curve is stable according to the irradiation is specifically as follows:

judging whether the error between the linear saturated output parameters collected each time is +/-1000 DN, and collecting each timeWhether the error between the total gain parameters of the set is + -0.05 DN/e ^- 。

7. The method for on-line testing of an illuminated area array CCD according to claim 6, wherein:

in the step 1.2, the experimental environment temperature is 25 degrees plus or minus 5 degrees;

in step 2.1, the value of N is 30;

in step 3.1, the value of n is 100.

8. An on-line testing system for an irradiation-based planar array CCD, for implementing the on-line testing method for an irradiation-based planar array CCD according to any one of claims 1 to 6, characterized in that: comprises a radiation source (1), a light source (2), a driving controller (7), an irradiation plate (5) and an acquisition processor (11) which is arranged outside the irradiation chamber and connected with the driving controller (7);

a CCD driving circuit (52) is arranged on the irradiation plate (5);

a signal shielding box (8) is arranged outside the driving controller (7);

the outgoing light paths of the radiation source (1) and the light source (2) are used for arranging CCD devices to be irradiated, and the CCD driving circuit (52) is connected with the CCD devices to be irradiated;

the driving controller (7) comprises an A/D conversion module (71) and an FPGA main control module (72);

the FPGA main control module (72) is respectively connected with the CCD driving circuit (52), the A/D conversion module (71) and the acquisition processor (11);

the A/D conversion module (71) is connected with the CCD device to be irradiated;

the A/D conversion module (71) is used for carrying out double sampling treatment on an original CCD analog signal of the CCD device to be irradiated, converting the original CCD analog signal into a digital signal and transmitting the digital signal to the FPGA main control module (72);

the FPGA main control module (72) is used for generating a time sequence driving signal meeting the voltage requirement of the CCD device to be irradiated and transmitting the digital signal to the acquisition processor (11);

the CCD driving circuit (52) is used for converting the time sequence driving signal into a CCD driving signal so as to drive the CCD device to be irradiated.

9. An on-line testing system for irradiating an underlying array CCD according to claim 8, wherein:

the light source moving motor (3) is connected with the light source (2) and is used for controlling the up-down position of the light source (2);

and a CCD socket (51) connected with a CCD driving circuit (52) is also arranged on the irradiation plate (5).

10. An on-line testing system for irradiating an underlying array CCD according to claim 9, wherein:

the device also comprises a motion motor (6) connected with the irradiation plate (5) and used for adjusting the position of the CCD device to be irradiated by driving the irradiation plate (5) to move up and down.