Mechanical cryocooler technology are one of the significant technologies for earth and space scientific exploration. To meet the needs of future applications of infrared and millimeter wave detectors, Shanghai Institute of Technology Physics, Chinese Academy of Sciences (SITP, CAS) has developed a helium Joule-Thomson cryocooler (JTC) below 4.5 K for space applications. As the two most important components of the helium JT cryocooler, the precooler and the JT compressor are both developed by SITP. The precooler is a two-stage pulse tube cryocooler, and the JT compressor is an oil-free linear compressor, all of which can achieve long-life operation. First, a 4 K JTC was developed, experimental results show that after about 11 hours of cooling, the 4 K JTC successfully reached the liquid helium temperature and has a cooling performance of at least 110 mW@4 K.
{"title":"Helium Joule-Thomson cryocooler below 4.5 K for infrared detectors","authors":"Zhichao Chen, Shaoshuai Liu, Zhenhua Jiang, Lei Ding, Zheng Huang, Yinong Wu","doi":"10.1117/12.2665290","DOIUrl":"https://doi.org/10.1117/12.2665290","url":null,"abstract":"Mechanical cryocooler technology are one of the significant technologies for earth and space scientific exploration. To meet the needs of future applications of infrared and millimeter wave detectors, Shanghai Institute of Technology Physics, Chinese Academy of Sciences (SITP, CAS) has developed a helium Joule-Thomson cryocooler (JTC) below 4.5 K for space applications. As the two most important components of the helium JT cryocooler, the precooler and the JT compressor are both developed by SITP. The precooler is a two-stage pulse tube cryocooler, and the JT compressor is an oil-free linear compressor, all of which can achieve long-life operation. First, a 4 K JTC was developed, experimental results show that after about 11 hours of cooling, the 4 K JTC successfully reached the liquid helium temperature and has a cooling performance of at least 110 mW@4 K.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117295312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Near infrared spectroscopy has been applied to qualitative and quantitative analysis in many fields due to its advantages of fast measurement speed, high accuracy and continuous measurement. Digital micromirror array is an electronic input and output optical mems, semiconductor manufacturing technology combined with the height of the integrated circuit manufacturing technology, make its in resolution, contrast, brightness, grayscale, color fidelity and main performance parameters, such as response time reached the high level, high reliability, fast response speed. In recent years, near-infrared spectroscopy based on wavelength grating and modulation characteristics of DMD has become a research hotspot. This system has the advantages of high signal-to-noise ratio, excellent comprehensive performance and low cost, and has attracted much attention in many application fields. In this paper, the principle, development history, application status and development direction of near infrared spectroscopy based on DMD are reviewed, which provides a basis for the related research of DMD near infrared spectroscopy analysis technology.
{"title":"Research on near infrared spectroscopy based on DMD","authors":"Yujuan Liu, Yan-da Liu, Ying Song","doi":"10.1117/12.2664753","DOIUrl":"https://doi.org/10.1117/12.2664753","url":null,"abstract":"Near infrared spectroscopy has been applied to qualitative and quantitative analysis in many fields due to its advantages of fast measurement speed, high accuracy and continuous measurement. Digital micromirror array is an electronic input and output optical mems, semiconductor manufacturing technology combined with the height of the integrated circuit manufacturing technology, make its in resolution, contrast, brightness, grayscale, color fidelity and main performance parameters, such as response time reached the high level, high reliability, fast response speed. In recent years, near-infrared spectroscopy based on wavelength grating and modulation characteristics of DMD has become a research hotspot. This system has the advantages of high signal-to-noise ratio, excellent comprehensive performance and low cost, and has attracted much attention in many application fields. In this paper, the principle, development history, application status and development direction of near infrared spectroscopy based on DMD are reviewed, which provides a basis for the related research of DMD near infrared spectroscopy analysis technology.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125496814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jing Qian, Y. Cheng, Shukui Ma, Xiaoming Lu, Maotong Huang, Peng Rao, Yaopu Zou
Flexible thermal strap is a key component for space optical system to realize cold transfer, insulate vibration. The thermal link based on high thermal conductivity graphene film becomes a hot spot for this application. In order to reduce the loss in the heat transfer process, a study on the heat transfer performance and structural form of the thermal link made by pyrolytic graphite films (PGF) is carried out, the thermal resistance network model of the thermal strap is analyzed, the relationship between the heat transfer, the heat transfer temperature difference at the mounting surface and the number of graphite film layers is established by combining theoretical analysis and DOE design methods. A method for quickly determining the design parameters of the thermal strap is proposed. The PGF thermal strap designed according to this method achieves a small temperature difference which less than 1.7K between the cold tip and the simulated optical bench coupling surface, a length of 117mm for the strap, and a weight of only 60g, when it used to transfer 5W cooling capacity at 200K.
{"title":"A design method of flexible thermal strap for cryogenic optics based on pyrolytic graphite film","authors":"Jing Qian, Y. Cheng, Shukui Ma, Xiaoming Lu, Maotong Huang, Peng Rao, Yaopu Zou","doi":"10.1117/12.2665693","DOIUrl":"https://doi.org/10.1117/12.2665693","url":null,"abstract":"Flexible thermal strap is a key component for space optical system to realize cold transfer, insulate vibration. The thermal link based on high thermal conductivity graphene film becomes a hot spot for this application. In order to reduce the loss in the heat transfer process, a study on the heat transfer performance and structural form of the thermal link made by pyrolytic graphite films (PGF) is carried out, the thermal resistance network model of the thermal strap is analyzed, the relationship between the heat transfer, the heat transfer temperature difference at the mounting surface and the number of graphite film layers is established by combining theoretical analysis and DOE design methods. A method for quickly determining the design parameters of the thermal strap is proposed. The PGF thermal strap designed according to this method achieves a small temperature difference which less than 1.7K between the cold tip and the simulated optical bench coupling surface, a length of 117mm for the strap, and a weight of only 60g, when it used to transfer 5W cooling capacity at 200K.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123235436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The performance of the Advanced Geosynchronous Radiation Imager (AGRI) onboard the Fengyun-4 (FY-4) satellite was evaluated. The results showed that its performance has approached the international advanced level of similar instruments. A wavelet filter was designed to filter the striping noises of the AGRI, which come from the inconsistency of the spectrum and thus varies with the observed target. The non-uniformity of the whole image was evaluated by weighting the probability variance of its count values. After filtering, the infrared image of the AGRI had a uniform visual effect on a single channel, and the pattern noise was reduced to below 0.2 K, which ensures the uniformity of products such as cloud detection and sea temperature that use the infrared splitting window channels. Furthermore, the AGRI carries the surface source blackbody as the on-orbit radiation calibration benchmark and rotates the north-south scanning mirror to point to the blackbody to obtain the blackbody observation data in each infrared band. In the current mode, the infrared calibration is performed every 15 minutes. The long-term evaluation results showed that the radiation calibration accuracy of the infrared channels of the AGRI was better than 0.5 K, and some of the channels reached 0.2 K. In addition, the long-term monitoring of the sensitivity and radiative cooling of the AGRI has shown the on-orbit variation of the instrument, which provides a reference for the development of the subsequent instrument.
{"title":"On-orbit performance of Fengyun-4A advanced geosynchronous radiation imager","authors":"Boyang Chen, Changpei Han, Q. Guo, W. Hui, Qiong Wu, Xiuju Li, Yapeng Wu","doi":"10.1117/12.2665856","DOIUrl":"https://doi.org/10.1117/12.2665856","url":null,"abstract":"The performance of the Advanced Geosynchronous Radiation Imager (AGRI) onboard the Fengyun-4 (FY-4) satellite was evaluated. The results showed that its performance has approached the international advanced level of similar instruments. A wavelet filter was designed to filter the striping noises of the AGRI, which come from the inconsistency of the spectrum and thus varies with the observed target. The non-uniformity of the whole image was evaluated by weighting the probability variance of its count values. After filtering, the infrared image of the AGRI had a uniform visual effect on a single channel, and the pattern noise was reduced to below 0.2 K, which ensures the uniformity of products such as cloud detection and sea temperature that use the infrared splitting window channels. Furthermore, the AGRI carries the surface source blackbody as the on-orbit radiation calibration benchmark and rotates the north-south scanning mirror to point to the blackbody to obtain the blackbody observation data in each infrared band. In the current mode, the infrared calibration is performed every 15 minutes. The long-term evaluation results showed that the radiation calibration accuracy of the infrared channels of the AGRI was better than 0.5 K, and some of the channels reached 0.2 K. In addition, the long-term monitoring of the sensitivity and radiative cooling of the AGRI has shown the on-orbit variation of the instrument, which provides a reference for the development of the subsequent instrument.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"697 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122970014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ningyuan Zhang, Chengzhi Deng, Shaoquan Zhang, Fan Li, Pengfei Lai, Min Huang, Shengqian Wang
Hyperspectral unmixing aims to correctly estimate the endmembers and their corresponding abundance fractions in an HSI. Many hyperspectral unmixing methods have been proposed, including the longstanding geometry-based, statistics-based and non-negative matrix factorization (NMF)-based unmixing methods. The traditional NMF-based method expands the three-dimensional hyperspectral data into matrix form and decomposes it into the product of the endmember and the abundance, which causes a certain degree of information loss. The matrix-vector nonnegative tensor factorization algorithm solves this problem well by processing hyper-spectral data as a tensor and pioneers a new model based on tensor decomposition. However, such methods still suffer from underutilization of image information and unstable performance at low signal-to-noise ratios (SNR). To solve this problem, we proposed a new superpixel-based spatial weighted sparse nonnegative tensor factorization unmixing model (SupSWNTF), which better exploits the spatial information and improve the sparsity of the solution by adding constraints to the abundance matrix. A series of comparative experimental results on synthetic and real-world data sets show that our algorithm achieves the best unmixing results compared to other state-of-the-art algorithms.
{"title":"Superpixel-based spatial weighted sparse nonnegative tensor factorization unmixing algorithm","authors":"Ningyuan Zhang, Chengzhi Deng, Shaoquan Zhang, Fan Li, Pengfei Lai, Min Huang, Shengqian Wang","doi":"10.1117/12.2665583","DOIUrl":"https://doi.org/10.1117/12.2665583","url":null,"abstract":"Hyperspectral unmixing aims to correctly estimate the endmembers and their corresponding abundance fractions in an HSI. Many hyperspectral unmixing methods have been proposed, including the longstanding geometry-based, statistics-based and non-negative matrix factorization (NMF)-based unmixing methods. The traditional NMF-based method expands the three-dimensional hyperspectral data into matrix form and decomposes it into the product of the endmember and the abundance, which causes a certain degree of information loss. The matrix-vector nonnegative tensor factorization algorithm solves this problem well by processing hyper-spectral data as a tensor and pioneers a new model based on tensor decomposition. However, such methods still suffer from underutilization of image information and unstable performance at low signal-to-noise ratios (SNR). To solve this problem, we proposed a new superpixel-based spatial weighted sparse nonnegative tensor factorization unmixing model (SupSWNTF), which better exploits the spatial information and improve the sparsity of the solution by adding constraints to the abundance matrix. A series of comparative experimental results on synthetic and real-world data sets show that our algorithm achieves the best unmixing results compared to other state-of-the-art algorithms.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121756778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Xu, Xuan Dong, Zikun Zeng, Jie Shu, Hongzhu Xi
The fingerprint technology of traditional Chinese medicine is a more effective method to ensure the quality stability of traditional Chinese medicine and control the quality of traditional Chinese medicine. As the core of fingerprint technology of traditional Chinese medicine, terahertz time-domain spectroscopy (THz-TDS) is very suitable for the detection of traditional Chinese medicine. In this paper, a free-space transmission terahertz time-domain spectroscopy system developed by us was used to detect the compound banlangen tablets. The absorption spectra and refractive index spectra of the compound banlangen tablets with different thicknesses, manufacturers and batches were studied. The results showed that: the difference in thickness, batch and manufacturer didn’t affect the terahertz characteristic absorption peak position of compound banlangen tablet, and there were two obvious absorption peaks (1.10THz, 1.17THz) in the tablets; the increase of the thickness caused the absorption peak of the tablet to become smaller and even disappear, and the refractive indexes of tablets with different thicknesses were also quite different; The absorption peaks of tablets with different batches were roughly the same, and the refractive indexes were slightly different; The absorption peaks and refractive indexes of tablets from different manufacturers were basically the same. The above work will help to improve the terahertz fingerprint of compound banlangen, and provide detection means and reference for enriching the quality standard of traditional Chinese medicine.
{"title":"Preliminary study on compound banlangen granules based on terahertz time-domain spectroscopy","authors":"Wei Xu, Xuan Dong, Zikun Zeng, Jie Shu, Hongzhu Xi","doi":"10.1117/12.2665562","DOIUrl":"https://doi.org/10.1117/12.2665562","url":null,"abstract":"The fingerprint technology of traditional Chinese medicine is a more effective method to ensure the quality stability of traditional Chinese medicine and control the quality of traditional Chinese medicine. As the core of fingerprint technology of traditional Chinese medicine, terahertz time-domain spectroscopy (THz-TDS) is very suitable for the detection of traditional Chinese medicine. In this paper, a free-space transmission terahertz time-domain spectroscopy system developed by us was used to detect the compound banlangen tablets. The absorption spectra and refractive index spectra of the compound banlangen tablets with different thicknesses, manufacturers and batches were studied. The results showed that: the difference in thickness, batch and manufacturer didn’t affect the terahertz characteristic absorption peak position of compound banlangen tablet, and there were two obvious absorption peaks (1.10THz, 1.17THz) in the tablets; the increase of the thickness caused the absorption peak of the tablet to become smaller and even disappear, and the refractive indexes of tablets with different thicknesses were also quite different; The absorption peaks of tablets with different batches were roughly the same, and the refractive indexes were slightly different; The absorption peaks and refractive indexes of tablets from different manufacturers were basically the same. The above work will help to improve the terahertz fingerprint of compound banlangen, and provide detection means and reference for enriching the quality standard of traditional Chinese medicine.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123896703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electromagnetic induced transparency (EIT) refers to the phenomenon of a sharp transmission window in a broad absorption profile, which was first discovered in the interference between the electronic transition paths of three energy levels. In this work, a metasurface structure with EIT is designed by coupling a dark-like mode and a bright mode. In order to make its resonance intensity dynamically adjustable, the metasurface structure in this paper adds a structure composed of vanadium dioxide (VO2) to the original EIT structure. When vanadium dioxide is at different temperature, its conductivity is different, and the degree of participation in metasurface resonance is different. Thus, the dynamic tuning of the EIT resonance intensity is realized, and the modulation depth can reach 76.18%.
{"title":"Dynamically tunable resonant strength in an electromagnetically induced transparency metasurface based on vanadium dioxide","authors":"Linyu Yang, W. Wang, Yi Sun, Rong Yin","doi":"10.1117/12.2665824","DOIUrl":"https://doi.org/10.1117/12.2665824","url":null,"abstract":"Electromagnetic induced transparency (EIT) refers to the phenomenon of a sharp transmission window in a broad absorption profile, which was first discovered in the interference between the electronic transition paths of three energy levels. In this work, a metasurface structure with EIT is designed by coupling a dark-like mode and a bright mode. In order to make its resonance intensity dynamically adjustable, the metasurface structure in this paper adds a structure composed of vanadium dioxide (VO2) to the original EIT structure. When vanadium dioxide is at different temperature, its conductivity is different, and the degree of participation in metasurface resonance is different. Thus, the dynamic tuning of the EIT resonance intensity is realized, and the modulation depth can reach 76.18%.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"4 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123900986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Baicheng Sun, Yongsheng Xiang, Mingxing Fan, Xiaoxia Gong, Bin Wang, Jie Guo, Fangyu Xu
The infrared spectra of the Sun include numerous absorption lines, among which He I 10830 Å is one of the most representative spectral lines in the near-infrared band formed in the high-temperature region of the upper chromosphere. The observation of the spectral lines is important for the solar physics research. In this paper, the monochromatic images of sunspots in the He I 10830 Å spectral line was obtained by the one-meter new vacuum solar telescope at the Fuxian Lake solar observation base. The infrared detector using the domestic InGaAs 640×512 focal plane array device can reach a low dark current of 62e-/s/pixel and readout noise of 25.4 e- at 78K by Stirling cooler. The laboratory tests and actual astronomical observations were completed. In the case of large detector readout noise and dark current, a method of extracting the observation target by effectively calculating the flat field was proposed. A monochromatic image of sunspots with He I 10830 Å is obtained for the first time in China using the self-developed detector.
太阳的红外光谱包括许多吸收谱线，其中He I 10830 Å是在上层色球高温区域形成的近红外波段中最具代表性的谱线之一。光谱线的观测对太阳物理研究具有重要意义。本文利用抚仙湖太阳观测基地的1米新型真空太阳望远镜，获得了He I 10830 Å光谱线上的太阳黑子单色图像。采用国产InGaAs 640×512焦平面阵列器件的红外探测器，经斯特林冷却器在78K时可达到62e-/s/pixel的低暗电流和25.4 e-的读出噪声。实验室测试和实际天文观测已经完成。针对检测器读出噪声大、暗电流大的情况，提出了一种通过有效计算平坦场提取观测目标的方法。利用自行研制的探测器，首次获得了太阳黑子He I 10830 Å的单色图像。
{"title":"Observation of sunspots at He I 10830Å using a low-noise InGaAs infrared detector","authors":"Baicheng Sun, Yongsheng Xiang, Mingxing Fan, Xiaoxia Gong, Bin Wang, Jie Guo, Fangyu Xu","doi":"10.1117/12.2664982","DOIUrl":"https://doi.org/10.1117/12.2664982","url":null,"abstract":"The infrared spectra of the Sun include numerous absorption lines, among which He I 10830 Å is one of the most representative spectral lines in the near-infrared band formed in the high-temperature region of the upper chromosphere. The observation of the spectral lines is important for the solar physics research. In this paper, the monochromatic images of sunspots in the He I 10830 Å spectral line was obtained by the one-meter new vacuum solar telescope at the Fuxian Lake solar observation base. The infrared detector using the domestic InGaAs 640×512 focal plane array device can reach a low dark current of 62e-/s/pixel and readout noise of 25.4 e- at 78K by Stirling cooler. The laboratory tests and actual astronomical observations were completed. In the case of large detector readout noise and dark current, a method of extracting the observation target by effectively calculating the flat field was proposed. A monochromatic image of sunspots with He I 10830 Å is obtained for the first time in China using the self-developed detector.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123902274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jicai Rui, Qiaoyue Dong, Yujiao Liu, Wen Gao, Mingqian Shi
The structure of a space electric cabinet based on a commercial CMOS chip is presented. Analysis is conducted according to the temperature specifications and the environmental constraints, which indicates the partitional thermal control method has higher energy efficiency than conventional TEC cooling. A flexible graphite thermal cable is used to build an independent cooling path for the focal plane component. The camera hood is utilized to cool down the peripheral circuit. Copper sinks are designed for high power electronic components. The thermal control design is verified by finite element simulation analysis and thermal balance test. The experimental results show that the partitional thermal control measures are effective and feasible, which can ensure the -30°C operating temperature of CMOS chip and the derating requirements of components with high power consumption.
{"title":"Design and verification of partitional thermal control for space CMOS electric cabinet","authors":"Jicai Rui, Qiaoyue Dong, Yujiao Liu, Wen Gao, Mingqian Shi","doi":"10.1117/12.2666055","DOIUrl":"https://doi.org/10.1117/12.2666055","url":null,"abstract":"The structure of a space electric cabinet based on a commercial CMOS chip is presented. Analysis is conducted according to the temperature specifications and the environmental constraints, which indicates the partitional thermal control method has higher energy efficiency than conventional TEC cooling. A flexible graphite thermal cable is used to build an independent cooling path for the focal plane component. The camera hood is utilized to cool down the peripheral circuit. Copper sinks are designed for high power electronic components. The thermal control design is verified by finite element simulation analysis and thermal balance test. The experimental results show that the partitional thermal control measures are effective and feasible, which can ensure the -30°C operating temperature of CMOS chip and the derating requirements of components with high power consumption.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126270814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recycling scrap metal is an important way to protect the ecological environment. Design effective yet efficient techniques to automatically identify recyclable scrap metals is an important task within this topic. Due to the advantages of fast response and high accuracy, laser-induced breakdown spectroscopy (LIBS) recently played an important role in the mineral identification. However, the identification accuracy of peak-seeking is greatly affected by the data quality of the LIBS spectrum, whereas machine learning methods may be greatly affected by the number of training data. By considering the above open issues, this paper proposes a hybrid algorithm based on support vector machine (SVM) and element peak-seeking. By investing the identified difference of the major element (with the largest composition in the alloy) and the general element (with composition more than 1% in the alloy) between peak-seeking and SVM, three integration types (i.e., rejection, partial acceptance, complete acceptance) are defined. The final recognition result is generated according to different integration types and the corresponding integration methods. To verify the feasibility of the proposed approach, a simulated alloy LIBS database was established based on 31 metal elements and the simulated alloy LIBS data according to their compositions. Comparing with the result obtained by only using SVM, the proposed method greatly improved the recognition accuracy. The accuracy of identifying all general elements increased from 8% to 74.5%. Experimental results confirmed the effectiveness of the proposed method in identification of general metal elements in terms of higher detection accuracy.
{"title":"A hybrid approach for metal element identification by using laser-induced breakdown spectroscopy data","authors":"Haofeng Zeng, Zhuoxiang Zhang, Sicong Liu","doi":"10.1117/12.2664527","DOIUrl":"https://doi.org/10.1117/12.2664527","url":null,"abstract":"Recycling scrap metal is an important way to protect the ecological environment. Design effective yet efficient techniques to automatically identify recyclable scrap metals is an important task within this topic. Due to the advantages of fast response and high accuracy, laser-induced breakdown spectroscopy (LIBS) recently played an important role in the mineral identification. However, the identification accuracy of peak-seeking is greatly affected by the data quality of the LIBS spectrum, whereas machine learning methods may be greatly affected by the number of training data. By considering the above open issues, this paper proposes a hybrid algorithm based on support vector machine (SVM) and element peak-seeking. By investing the identified difference of the major element (with the largest composition in the alloy) and the general element (with composition more than 1% in the alloy) between peak-seeking and SVM, three integration types (i.e., rejection, partial acceptance, complete acceptance) are defined. The final recognition result is generated according to different integration types and the corresponding integration methods. To verify the feasibility of the proposed approach, a simulated alloy LIBS database was established based on 31 metal elements and the simulated alloy LIBS data according to their compositions. Comparing with the result obtained by only using SVM, the proposed method greatly improved the recognition accuracy. The accuracy of identifying all general elements increased from 8% to 74.5%. Experimental results confirmed the effectiveness of the proposed method in identification of general metal elements in terms of higher detection accuracy.","PeriodicalId":258680,"journal":{"name":"Earth and Space From Infrared to Terahertz (ESIT 2022)","volume":"12505 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129378548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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