阅读说明：本技术 一种真空低温环境用红外辐射计 (Infrared radiometer for vacuum low-temperature environment ) 是由 翟思婷 孙红胜 张玉国 王加朋 赵丹 吴柯萱 于 2020-05-15 设计创作，主要内容包括：本发明提供了一种真空低温环境用红外辐射计,包括真空冷舱及舱内平台上按照光路传播方向依次设置的消杂光遮光罩、主镜、真空斩波器、视场光阑、次镜、制冷型红外探测器,待校准设备通过法兰安装在真空冷舱侧壁上对准消杂光遮光罩,制冷型红外探测器的杜瓦瓶瓶盖上设置进液氮管路和出氮气管路,分别与真空冷舱法兰盘上的进液氮管路和出氮气管路连通。本发明采用真空冷舱模拟真空低温环境,采用制冷型红外探测器探测超微弱红外辐射信号,能够测量200K～400K的超微弱宽温度范围红外辐射,可为红外载荷性能测试设备提供有效保障。(The invention provides an infrared radiometer for a vacuum low-temperature environment, which comprises a vacuum cold chamber and an impurity light eliminating light shield, a primary mirror, a vacuum chopper, a field diaphragm, a secondary mirror and a refrigeration type infrared detector which are sequentially arranged on a platform in the vacuum cold chamber according to the propagation direction of a light path, wherein equipment to be calibrated is arranged on the side wall of the vacuum cold chamber through a flange and aims at the impurity light eliminating light shield, and a liquid nitrogen inlet pipeline and a liquid nitrogen outlet pipeline are arranged on a Dewar flask bottle cap of the refrigeration type infrared detector and are respectively communicated with the liquid nitrogen inlet pipeline and the liquid nitrogen outlet pipeline on a flange plate of the vacuum cold chamber. The invention adopts the vacuum cold cabin to simulate the vacuum low-temperature environment, adopts the refrigeration type infrared detector to detect the ultra-weak infrared radiation signal, can measure the ultra-weak wide temperature range infrared radiation of 200K-400K, and can provide effective guarantee for the infrared load performance testing equipment.)

1. An infrared radiometer for a vacuum low-temperature environment is characterized by comprising a vacuum cold chamber, and a stray light eliminating light shield, a main mirror, a vacuum chopper, a view field diaphragm, a secondary mirror and a refrigeration type infrared detector which are sequentially arranged on a platform in the vacuum cold chamber according to a light path propagation direction, wherein equipment to be calibrated is arranged on the side wall of the vacuum cold chamber through a flange and is aligned with the stray light eliminating light shield; a liquid nitrogen inlet pipeline and a nitrogen outlet pipeline are arranged on a Dewar flask bottle cap of the refrigeration type infrared detector and are respectively communicated with a liquid nitrogen inlet pipeline and a nitrogen outlet pipeline on a vacuum cold chamber flange plate through corrugated pipes, and the liquid nitrogen inlet pipeline is directly communicated with a detector at the bottom of the Dewar flask.

2. The infrared radiometer for vacuum low temperature environments as set forth in claim 1, wherein an optical system consisting of said primary mirror and said secondary mirror is of a grignard-two reflection type, and said field stop is disposed at a primary image plane of said optical system.

3. The infrared radiometer for vacuum low temperature environments of claim 1, wherein the vacuum chopper is externally provided with a multi-layer heat insulating structure.

4. The infrared radiometer for low temperature vacuum environment of claim 1, wherein the primary mirror, the secondary mirror, the cold chamber vacuum platform have temperature sensors disposed thereon.

5. The infrared radiometer for vacuum low temperature environment of claim 1, wherein the dewar bottle cap and the bottle body are in threaded connection, and the connection of the nitrogen outlet pipeline, the nitrogen inlet pipeline and the bottle cap, the connection of the bottle cap and the bottle body, and the connection of each pipeline and the corrugated pipe are sealed by winding raw material tapes.

6. The infrared radiometer for vacuum low temperature environments as set forth in claim 1, wherein said refrigerated type infrared detector comprises a refrigerated type medium wave detector and a refrigerated type long wave detector, and detection wavelength bands are respectively 3 μm to 5 μm and 8 μm to 12 μm.

7. The infrared radiometer for vacuum low temperature environment according to claim 1, wherein the vacuum cabin is further provided with a super weak signal amplification processing system and a computer, and the super weak signal amplification processing system collects the photoelectric signal of the refrigeration type infrared detector, processes the photoelectric signal and outputs the processed signal to the computer.

8. The infrared radiometer for use in low-temperature vacuum environments of claim 7, wherein said ultra-weak signal amplification processing system comprises a preamplifier for target signal amplification and a lock-in amplifier for signal coherent detection processing.

9. The infrared radiometer for vacuum cryogenic environments of claim 1, wherein the primary mirror and the secondary mirror are made of microcrystalline glass material with low expansion coefficient, the mechanical structure in the vacuum cold chamber is made of invar steel material with low expansion coefficient, and the liquid nitrogen inlet pipeline, the nitrogen outlet pipeline, the bottle cap and the corrugated pipe are made of stainless steel material.

10. The infrared radiometer for vacuum cryogenic environments of claim 1, wherein said primary mirror is an off-axis parabolic mirror, said secondary mirror is an off-axis ellipsoidal mirror, an entrance pupil aperture of an optical system consisting of said primary mirror and said secondary mirror is 95mm, an operating band is 3 μm to 5 μm, 8 μm to 12 μm, a focal length is 400mm, and a field angle is 1 mrad; the photosensitive surface of the refrigeration type infrared detector is 0.5mm multiplied by 0.5 mm.

Technical Field

The invention belongs to the field of infrared radiation, and particularly relates to an infrared radiometer for a vacuum low-temperature environment.

Background

With the development of aerospace technology, more and more infrared loads are applied to space detection, and the application fields include military, earth remote sensing, ocean detection, high-resolution earth observation and the like. The radiation parameter calibration is a basis and precondition for realizing quantitative detection of the infrared load, and the radiation quantity value of the target can be quantitatively detected through the radiation parameter calibration, so that the infrared load can judge the type of the target through the radiation quantity value, and the detection capability of the infrared load is greatly improved. Meanwhile, the radiation parameter calibration improves the data application efficiency of infrared loads such as a detection system and a remote sensing system.

The infrared load performance test equipment is the main calibration equipment of photoelectric detection systems such as infrared loads, infrared guide heads and the like. The stability and accuracy of the infrared load performance test equipment directly influence the technical indexes and performance of the infrared load. With the development of infrared load towards in-orbit cryogenic space, the detection targets mainly comprise ground buildings, natural landscapes, space satellites, space stations and the like. The infrared radiation energy of the targets is very weak, in order to detect weak infrared radiation, the working environment of the infrared load performance testing equipment needs to be consistent with the on-orbit space environment, weak target signals can be submerged by environmental noise and self heat radiation of a system under the normal temperature environment, and the target signals cannot be detected, so that the infrared load performance testing equipment is also developed towards the low temperature direction.

During production and delivery test of the infrared load performance testing equipment, in order to ensure excellent working performance of the infrared load performance testing equipment, temperature difference calibration needs to be carried out on the infrared load performance testing equipment, the equipment precision is improved, and in order to realize quantitative detection precision, a calibration state needs to be consistent with an on-orbit calibration state so as to ensure the effectiveness of calibration. Therefore, the calibration device is required to work stably and reliably in a vacuum low-temperature environment, and the infrared radiation value is ensured to be accurate and reliable, so that a set of infrared radiometer for the vacuum low-temperature environment is urgently required to be established for temperature difference calibration of low-temperature infrared load performance test equipment.

Disclosure of Invention

The invention provides an infrared radiometer for a vacuum low-temperature environment, which can solve the problem of calibration of the existing on-orbit space infrared load performance test equipment, can realize 200K-400K infrared radiation detection, and ensures accurate and reliable infrared radiation value.

The technical scheme adopted by the invention for solving the problems is as follows:

an infrared radiometer for a vacuum low-temperature environment comprises a vacuum cold chamber, and a stray light eliminating light hood, a primary mirror, a vacuum chopper, a field diaphragm, a secondary mirror and a refrigeration type infrared detector which are sequentially arranged on a platform in the vacuum cold chamber according to a light path propagation direction, wherein equipment to be calibrated is arranged on the side wall of the vacuum cold chamber through a flange and is aligned with the stray light eliminating light hood; a liquid nitrogen inlet pipeline and a nitrogen outlet pipeline are arranged on a Dewar flask bottle cap of the refrigeration type infrared detector and are respectively communicated with a liquid nitrogen inlet pipeline and a nitrogen outlet pipeline on a vacuum cold chamber flange plate through corrugated pipes, and the liquid nitrogen inlet pipeline is directly communicated with a detector at the bottom of the Dewar flask.

Furthermore, an optical system composed of the primary mirror and the secondary mirror is of a griigree reflection type, and the field diaphragm is arranged at a primary image surface of the optical system.

Furthermore, the vacuum chopper is externally provided with a multilayer heat insulation structure.

Furthermore, temperature sensors are arranged on the primary mirror, the secondary mirror and the vacuum cold cabin platform.

Furthermore, dewar bottle lid and bottle adopt threaded connection, go out nitrogen pipeline, feed liquor nitrogen pipeline and bottle lid junction, bottle lid and bottle junction, each pipeline and bellows junction all seal with winding thread seal area.

Furthermore, the refrigeration type infrared detector comprises a refrigeration type medium wave detector and a refrigeration type long wave detector, and detection wave bands are respectively 3-5 microns and 8-12 microns.

Furthermore, an ultra-weak signal amplification processing system and a computer are arranged outside the vacuum cabin, and the ultra-weak signal amplification processing system acquires photoelectric signals of the refrigeration type infrared detector, processes the signals and outputs the signals to the computer.

Furthermore, the ultra-weak signal amplification processing system comprises a preamplifier and a lock-in amplifier, wherein the preamplifier is used for amplifying a target signal, and the lock-in amplifier is used for signal coherent detection processing.

Furthermore, the primary mirror and the secondary mirror are made of microcrystalline glass materials with low expansion coefficients, the mechanical structure in the vacuum cold chamber is made of invar steel materials with low expansion coefficients, and the liquid nitrogen inlet pipeline, the nitrogen outlet pipeline, the bottle cap and the corrugated pipe are made of stainless steel materials.

Further, the primary mirror is an off-axis parabolic mirror, the secondary mirror is an off-axis ellipsoidal mirror, the entrance pupil diameter of an optical system consisting of the primary mirror and the secondary mirror is 95mm, the working wave band is 3-5 μm and 8-12 μm, the focal length is 400mm, and the field angle is 1 mrad; the photosensitive surface of the refrigeration type infrared detector is 0.5mm multiplied by 0.5 mm.

The invention has the beneficial effects that:

the infrared radiometer for the vacuum low-temperature environment provided by the invention adopts the vacuum cold chamber to simulate the vacuum low-temperature environment to calibrate the infrared load performance testing equipment, adopts the refrigeration type infrared detector to detect ultra-weak infrared radiation signals, and has the vacuum degree of 10^-3Pa, the working temperature can reach 100K, the ultra-weak wide temperature range infrared radiation of 200K-400K can be measured, and effective guarantee can be provided for infrared load performance testing equipment.

The refrigeration type infrared detector adopted by the invention has the advantages of short response time, high sensitivity, wide response wavelength and small limited background noise, can inhibit the generation of dark current, improve the signal-to-noise ratio of the detector, effectively improve the detection performance of ultra-weak signals and solve the problem that the weak signals are easily submerged by the background noise.

The invention improves the Dewar flask adopting the refrigeration type infrared detector, liquid nitrogen enters the detector through a flange liquid inlet nitrogen pipe of the vacuum bulkhead, nitrogen overflowing from the Dewar flask can be discharged out of the vacuum bulkhead through a flange nitrogen outlet pipe of the vacuum bulkhead, and the refrigeration type infrared detector is ensured to work for a long time in a vacuum low-temperature environment.

Stray radiation is effectively inhibited by adopting a stray light eliminating light shield and a field diaphragm in light path transmission.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic view of an infrared radiometer for use in a vacuum cryogenic environment in an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a Dewar flask of a refrigeration type infrared detector in an embodiment of the invention;

including the following reference numerals:

the system comprises a main mirror 1, a stray light eliminating light shield 2, a vacuum chopper 3, a field-of-view diaphragm 4, a refrigeration type infrared detector 5, a secondary mirror 6, a vacuum cold chamber 7, an ultra-weak signal amplification processing system 8, a computer 9, equipment to be calibrated 10, a bottle body 51, a bottle cover 52, a liquid nitrogen inlet pipeline 53, a liquid nitrogen outlet pipeline 54, a flange plate 71, a flange plate 72, a liquid nitrogen inlet pipeline 73, a nitrogen outlet pipeline 73 and a corrugated pipe 74.

Detailed Description

The present invention is described in detail below with reference to the attached drawings and the detailed description.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

As shown in fig. 1, the infrared radiometer for a vacuum low-temperature environment provided by the invention comprises a primary mirror 1, a stray light eliminating light shield 2, a vacuum chopper 3, a field diaphragm 4, a refrigeration type infrared detector 5, a secondary mirror 6, a vacuum cold chamber 7, an ultra-weak signal amplification processing system 8, a computer 9 and a device to be calibrated 10, wherein the stray light eliminating light shield 2, the primary mirror 1, the vacuum chopper 3, the field diaphragm 4, the secondary mirror 6 and the refrigeration type infrared detector 5 are sequentially arranged on a platform in the vacuum cold chamber 7 according to a light path propagation direction, the device to be calibrated 10 is installed on the side wall of the vacuum cold chamber 7 through a flange and aligned with the stray light eliminating light shield 2, the ultra-weak signal amplification processing system 8 is arranged outside the vacuum cold chamber 7, and is used for collecting photoelectric signals of the refrigeration type infrared detector 5 and outputting the photoelectric signals to the computer 9 after processing. The optical system consisting of the primary mirror 1 and the secondary mirror 6 is used for converging infrared radiation to the refrigeration type infrared detector 5; the stray light eliminating light shield 2 is used for inhibiting external stray light from entering the infrared radiometer; the vacuum chopper 3 is used for modulating an optical signal; the field diaphragm 4 is used for suppressing stray radiation outside the field of view of the optical system; the refrigeration type infrared detector 5 is used for detecting an ultra-weak infrared radiation signal and converting an optical signal into an electric signal; the vacuum cold chamber 7 is used for providing a vacuum low-temperature environment; the ultra-weak signal amplification processing system 8 is used for signal amplification and signal coherent detection processing; the computer 9 is used for data acquisition, related data calculation, display and output of processing results and the like.

In this embodiment, the optical system composed of the primary mirror 1 and the secondary mirror 6 is of an off-axis two-reflection type, specifically, a griighland two-reflection type optical system, and the field stop 4 is disposed at the primary image plane of the optical system, so that a good stray light eliminating effect is achieved. The aperture of the entrance pupil of the optical system is 95 mm; the working wave band is 3-5 μm, 8-12 μm; the focal length is 400 mm; field angle 1 mrad; the primary mirror 1 is an off-axis parabolic mirror, and the secondary mirror 6 is an off-axis ellipsoidal mirror; when the diameter of an imaging light spot of the optical system is 0.1mm, the radial energy is close to 100%, the energy concentration is good, and the non-parallelism of the optical system is less than 3'.

In order to ensure that the deformation of an optical system consisting of the primary mirror 1 and the secondary mirror 6 in a vacuum low-temperature environment does not affect the imaging quality, in the overall optical machine structure, the primary mirror 1 and the secondary mirror 6 of the optical lens are made of microcrystalline glass materials with low expansion coefficients, and all mechanical structures in an optical path are made of invar 36 materials with low expansion coefficients. In this embodiment, the overall optical machine structure performs high and low temperature environment simulation, as shown in table 1, the lens is at 110K, 10K^-3Under the Pa condition, the displacement change quantity in the three directions of the x axis, the y axis and the z axis is small, and the imaging quality of the optical system cannot be influenced.

TABLE 1 results of displacement variation after simulation analysis

The vacuum chopper 3 is a heating component, and a multilayer heat insulation structure is adopted outside to prevent heat dissipation.

The refrigeration type infrared detector 5 adopts a dual-band detector which is respectively a refrigeration type medium-wave detector and a refrigeration type long-wave detector, the detection bands are respectively 3-5 mu m and 8-12 mu m, and the photosensitive surface is 0.5mm multiplied by 0.5 mm. Refrigeration type infrared detector 5 encapsulates in the dewar bottle, adopts the liquid nitrogen to refrigerate, and the liquid nitrogen pours into the dewar bottle and refrigerates the detector into, and detector operating temperature is liquid nitrogen boiling point 77K. Because the detector can normally work after liquid nitrogen is injected, if the detector filled with the liquid nitrogen is directly placed into the vacuum cooling cabin, when the vacuum cooling cabin is vacuumized, nitrogen can overflow from a liquid nitrogen inlet of the detector to cause that the vacuum degree can not be reduced, the working time of the detector filled with the liquid nitrogen is short, and the refrigerating time of the vacuum cooling cabin is long to cause that the liquid nitrogen in the detector can be completely consumed and can not normally work when the system is not cooled to a temperature point required by simulation.

In the invention, liquid nitrogen needs to be injected into the Dewar flask from the outside of the vacuum cold chamber 7 to refrigerate the detector, nitrogen volatilized by the Dewar flask also needs to be led out of the vacuum cold chamber 7, and the Dewar flask is reformed in order to ensure that the refrigeration type infrared detector 5 works normally and prevent the liquid nitrogen from leaking in the vacuum cold chamber 7. As shown in fig. 2, a bottle cap 52 of the dewar bottle is connected with a bottle body 51 by screw threads, a liquid nitrogen inlet pipeline 53 is arranged above the bottle cap 52 and is communicated with a detector at the bottom of the dewar bottle, a nitrogen outlet pipeline 54 is arranged at the side of the bottle cap 52, the liquid nitrogen inlet pipeline 53 and the nitrogen outlet pipeline 54 of the dewar bottle are respectively communicated with a liquid nitrogen inlet pipeline 72 and a nitrogen outlet pipeline 73 on a flange 71 of the vacuum cold chamber by a corrugated pipe 74, and the pipelines are connected with the corrugated pipe by screw threads. The joints of the nitrogen outlet pipeline 54, the liquid inlet pipeline 53 and the bottle cap 52, the joints of the bottle cap 52 and the bottle body 51 and the joints of the pipelines and the corrugated pipes are all wrapped with raw material belts to prevent leakage of liquid nitrogen and nitrogen. The liquid inlet nitrogen pipeline, the nitrogen outlet pipeline and the bottle cap of the Dewar bottle are made of stainless steel materials, and the corrugated pipe is also made of stainless steel materials and is not easy to deform and damage in a vacuum low-temperature environment. The dewar bottle after the transformation, liquid nitrogen gets into the detector through the flange feed liquor nitrogen pipe of vacuum bulkhead, and the nitrogen gas that overflows is gone out the nitrogen pipe and is discharged outside the vacuum bulkhead through the flange of vacuum bulkhead by dewar bottle play nitrogen pipe, guarantees that refrigeration type infrared detector works for a long time in the vacuum low temperature environment. When detecting different wave bands, the refrigeration type medium-wave and long-wave detectors in the vacuum cooling cabin need to be manually switched.

In order to accurately control the ambient temperature of the vacuum cooling chamber 7, temperature sensors are arranged on the primary mirror 1, the secondary mirror 6 and the vacuum cooling chamber platform, and the ambient temperature is monitored in real time from the outside of the chamber. In addition, when the device is used, the infrared radiation performance of the device to be calibrated 10 is known, the device to be calibrated 10 and the vacuum low-temperature environment are integrally simulated by an infrared radiometer through Tracepro software, and the ambient temperature required by the vacuum cold chamber during calibration is obtained by simulating the spontaneous radiation and target radiation of each part of the system and analyzing the signal-to-noise ratio.

The ultra-weak signal amplification processing system 8 includes a preamplifier for amplifying a target signal and a lock-in amplifier for performing signal coherent detection processing by using a reference signal frequency correlated with an input signal frequency and uncorrelated with a noise frequency to extract a useful signal from the noise. The ultra-weak signal amplification processing system 8 suppresses noise by analyzing and processing target infrared radiation.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

The invention has not been described in detail and is in part known to those of skill in the art.