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15th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics, CISP-BMEI 2022

作者： Wang, Heng Yuan, Yanrong Zhuang, Chuangang Shi, Rui Zhao, Jiamei Guo, Xinyi Tang, Jintian China Academy of Launch Vehicle Technology Science and Technology on Space Physics Laboratory Beijing100076 China Institute of Medical Physics and Engineering Tsinghua University Key Laboratory of Particle Technology and Radiation Imaging of Ministry of Education Department of Engineering Physics Beijing100084 China

ISBN: (数字)9781665488877

ISBN: (纸本)9781665488877

With the continuous development of aerial photography technology, its imaging quality is higher and higher, and the post-processing technology requirements for aerial images are getting higher and higher. Aerial image target recognition technology has been a hot research content in recent years. This technology relies on computer vision and image processing algorithm. But aerial images have certain particularities, including long shooting distances, complex image backgrounds, and variable target angles. The above factors can easily lead to indistinguishability between the target boundary and the background information of the aerial images. In order to solve that problem, a smooth edge feature information recognition method for aerial images is proposed. The energy fitting term related to the gray value inside and outside the curve is introduced, with that the method can get rid of the dependence of the detection operator as the stopping function of the curve evolution. In order to prevent the algorithm from falling into a local optimal solution in the iterative process, the Dirac function with a non-zero value in the domain is adopted. With synthetic and natural images, the effectiveness and accuracy of the method is verified. The robustness of the algorithm will be verified in the future researches by the acquired aerial image data set. © 2022 IEEE.

关键词： Aerial photography

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Research on Neutron Penetration Characteristics of Structural Materials for Near Space Vehicles 7

Research on Neutron Penetration Characteristics of Structura...

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7th International Conference on Signal and Image Processing, ICSIP 2022

作者： Wang, Heng Zhao, Jiamei Lan, Jinghui Yuan, Yanrong Shi, Rui Guo, Xinyi Tang, Jingtian Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle Technology Beijing100076 China Tsinghua University Key Laboratory of Particle Technology and Radiation Imaging of Ministry of Education Institute of Medical Physics and Engineering Department of Engineering Physics Beijing100084 China

ISBN: (数字)9781665495639

ISBN: (纸本)9781665495639

Traditional weapon systems and near-space vehicles may face severe intra-atmospheric or extra-atmospheric nuclear explosion environments during combat flight. Nuclear explosions can produce large-scale and comprehensive destructive effects, which bring great challenges to the performance and survival of weapon systems. In the nearby space of tens of kilometers, due to the gradual thinning of the air, the ray particles can travel a considerable distance. Considering the above situation, the neutron radiation penetration rate of the specified material by modeling the aircraft structural material and particle source is given in this research. According to the simulation analysis, the neutron ray penetration rate has nothing to do with the number of neutrons when the thickness of the aircraft structural material remains unchanged. In conclusion, a basis for the subsequent assessment of the neutron radiation environment inside the aircraft is proposed, which can provide guidance for the damage assessment of electronic equipment and the design of anti-nuclear reinforcement. © 2022 IEEE.

关键词： Damage detection

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Calibration of the cryogenic measurement system of a resonant haloscope cavity

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Chinese physics C 2024年第7期48卷 31-37页

作者：贺冬樊洁高昕高宇 Nick Houston 姬忠庆金贻荣李闯李金勉李田军刘世航牛家树彭智慧孙亮孙铮王佳卫镨先吴利娜相忠诚杨峤立张驰张文星张欣郑东宁郑瑞丰周建勇 Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Institute of Physics Chinese Academy of SciencesBeijing 100190China College of Physics Sichuan UniversityChengdu 610065China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Institute of Theoretical Physics Faculty of ScienceBeijing University of TechnologyBeijing 100124China Beijing Academy of Quantum Information Sciences Beijing 100193China College of Mechanical and Electrical Engineering Wuyi UniversityNanping 354300China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Theoretical Physics Shanxi UniversityTaiyuan 030006China College of Physics and Optoelectronic Engineering Department of PhysicsJinan UniversityGuangzhou 510632China School of Sciences Xi'an Technological UniversityXi'an 710021China Tsung-Dao Lee Institute and School of Physics and Astronomy Shanghai Jiao Tong University800 Dongchuan RoadShanghai 200240China National Astronomical Observatories Chinese Academy of Sciences20ADatun RoadChaoyang DistrictBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant *** this paper,we describe the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factor Q_(1)=10^(4)whose operation at a temperature of 22 mK is based on a dilution *** readout system consists of High Electron Mobility Transistors working as cryogenic amplifiers at 4 K,plus room-temperature amplifiers and a spectrum analyzer for signal power *** tested the system with a superconducting two-level system based on a single-photon source in the microwave frequency *** obtained an overall 95.6 dB system gain and–71.4 dB attenuation in the cavity's input *** effective noise temperature of the measurement system is 7.5 K.

关键词： dark matter superconducting two-level system Mollow triplet

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Five-year in-orbit background of Insight-HXMT

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Radiation Detection technology and Methods 2023年第1期7卷 34-47页

作者： Jin-Yuan Liao Shu Zhang Juan Zhang Gang Li Zhi Chang Yu-Peng Chen Ming-Yu Ge Jing Jin Xue-Feng Lu Yuan You Xue-Lei Cao Yong Chen Yue Huang Wei-Chun Jiang Xiao-Bo Li Xu-Fang Li Zheng-Wei Li Cong-Zhan Liu Ying Tan Yan-Ji Yang Yi-Fei Zhang Hai-Sheng Zhao Fang-Jun Lu Yu-Peng Xu Jin-Lu Qu Li-Ming Song Shuang-Nan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadShijingshan DistrictBeijing 100049China Key Laboratory of Stellar and Interstellar Physics and School of Physics and Optoelectronics Xiangtan UniversityYuhu DistrictXiangtan 411105China University of Chinese Academy of Sciences 19A Yuquan RoadShijingshan DistrictBeijing 100049China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of Sciences20A Datun RoadChaoyang DistrictBeijing 100012China

Purpose We present the five-year in-orbit background evolution of Insight-HXMT since the launch,as well as the effects of the background model in data *** The backgrounds of the three main payloads,i.e.,low-energy telescope,medium-energy telescope,and high-energy telescope,are *** evolution of the background over time is obtained by simply comparing the background in every year during the in-orbit operation of *** The major observational characteristics of the Insight-HXMT in-orbit background are presented,including the light curve,spectrum,geographical distribution,and long-term *** systematic error in background estimation is investigated for every *** The observational characteristics of the five-year in-orbit background are consistent with our knowledge of the satellite design and the space environment,and the background model is still valid for the latest observations of Insight-HXMT.

关键词： Instrumentation:detectors Space vehicles:instruments Methods:data analysis X-rays:general

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Wavelength-dependent nonlinear wavefront shaping in 3D nonlinear photonic crystal

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Chinese Optics Letters 2024年第7期22卷 66-70页

作者： Yunze Wang Yan Sheng Shan Liu Ruwei Zhao Tianxiang Xu Tiefeng Xu Feng Chen Wieslaw Krolikowski Laboratory of Infrared Materials and Devices Research Institute of Advanced TechnologiesNingbo UniversityNingbo 315211China Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province Ningbo UniversityNingbo 315211China Quantum Science and Technology Research School of PhysicsAustralian National UniversityCanberraACT 2601Australia Ningbo Institute of Oceanography Ningbo 315832China State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation of the Ministry of Education School of PhysicsShandong UniversityJinan 250100China

A 3D nonlinear photonic crystal containing four parallel segments of periodicχ^((2))grating structure is fabricated employing the femtosecond laser poling of ferroelectric Ca_(0.28)Ba_(0.72)Nb_(2)O_(6) *** second harmonic generation from this foursegment structure is studied with a fundamental Gaussian *** tuning the wavelength of the fundamental wave,the second harmonic varies from the Laguerre-Gaussian beam(topological charge l_(c)=1)to the higher-order Hermite-Gaussian beam and Laguerre-Gaussian again(l_(c)=−1).This effect is caused by the wavelength-dependent phase delays introduced by the four-grating *** study contributes to a deeper understanding of nonlinear wave interactions in 3D nonlinear photonic *** also offers new possibilities for special beam generation at new frequencies and their control.

关键词： quasi-phase matching nonlinear photonic crystal second harmonic generation nonlinear beam shaping

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Dynamical-invariant-based holonomic quantum gates:Theory and experiment

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Fundamental Research 2023年第2期3卷 229-236页

作者： Yingcheng Li Tao Xin Chudan Qiu Keren Li Gangqin Liu Jun Li Yidun Wan Dawei Lu State Key Laboratory of Surface Physics Department of PhysicsCenter for Field Theory and Particle Physicsand Institute for Nanoelectronic devices and Quantum computingFudan UniversityShanghai 200433China Shanghai Qi Zhi Institute Shanghai 200030China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China d Guangdong Provincial Key Laboratory of Quantum Science and Engineering Shenzhen 518055GuangdongChina Center for Quantum Computing Peng Cheng LaboratoryShenzhen 518055China Institute of Physics Chinese Academy of SciencesBeijing 100190China

Among existing approaches to holonomic quantum computing,the adiabatic holonomic quantum gates(HQGs)suffer errors due to decoherence,while the non-adiabatic HQGs either require additional Hilbert spaces or are difficult to ***,we report a systematic,scalable approach based on dynamical invariants to realize HQGs without using additional Hilbert *** presenting the theoretical framework of our approach,we design and experimentally evaluate single-qubit and two-qubits HQGs for the nuclear magnetic resonance *** single-qubit gates acquire average fidelity 0.9972 by randomized benchmarking,and the controlled-NOT gate acquires fidelity 0.9782 by quantum process *** approach is also platform-independent,and thus may open a way to large-scale holonomic quantum computation.

关键词： Geometric gates Dynamical invariant Nuclear magnetic resonance Holonomic gates Platform-independent

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Development of μSR apparatuses for a pulsed muon source at China Spallation Neutron Source

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Nuclear and particle physics Proceedings 2024年 344卷 8-13页

作者： Pan, Z.W. Yang, T.Y. Lin, Z.B. Wang, Z. He, Z.Y. Yuan, Y. Ni, X.J. Liu, J.D. Liang, H. Ye, B.J. Li, Q. Bao, Y. Li, Y. Cheng, H. Hu, H.T. Yu, Y.J. Tang, J.Y. Xie, F. Cottrell, S.P. Pooley, D.E. State Key Laboratory of Particle Detection and Electronics University of Science and Technology of China Hefei 230026 China Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Spallation Neutron Source Science Center Dongguan 523803 China Key Laboratory of Nuclear Physics Ion-beam Application (MOE) Fudan University Shanghai 200433 China ISIS Facility STFC Rutherford Appleton Laboratory Oxfordshire Chilton OX11 0QX United Kingdom

Muon spin rotation/relaxation/resonance (μSR) spectroscopy uses highly polarized muons to study the microscopic magnetic structure and dynamics of condensed matter. In addition to the five existing muon facilities, the first Chinese muon source, the Muon station for sciEnce technology and inDustrY (MELODY), is planned to be constructed in Phase II of the China Spallation Neutron Source (CSNS). It aims to provide intense and pulsed muon beams to conduct μSR applications in multiple disciplines. The group from the University of Science and technology of China (USTC) participated in the collaboration with the CSNS accelerator group for the construction of the muon source. The USTC group led the research and development (R&D) of the first-generation photomultiplier tube (PMT)-based μSR spectrometer, and the design of the second-generation silicon photomultiplier (SiPM)-based spectrometer. The PMT-based spectrometer is a 128-channel prototype to demonstrate and develop key detector and electronics technologies for the planned MELODY. After several iterative designs and updates of detectors and electronics, the spectrometer prototype achieved a 7-ns dead time, which can record more than 12 positrons per channel per pulse according to the ISIS running experience. Based on the technologies developed from the first-generation spectrometer, the second-generation spectrometer will use SiPMs to accommodate over 2500 detector units to make better use of muons in MELODY. The two generation developments of Chinese μSR spectrometers will greatly advance the construction of MELODY, and provide high-quality data for users to interpret material properties in the near future. © 2024 Elsevier B.V.

关键词： CSNS MELODY PMT SiPM μSR spectrometer

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Research on trigger technology of MRPC TOF-PET system and imaging results of 22Na radioactive source

arXiv

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arXiv 2025年

作者： Liu, Jianing Ma, Yuelei Chen, Ziyang Li, Zhenyan Wang, Yi Guo, Baohong Han, Dong Li, Yuanjing Key Laboratory of Particle and Radiation Imaging Department of Engineering Physics Tsinghua University Beijing100084 China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of China Hefei230026 China Modern Physics Department University of Science and Technology of China Hefei230026 China

This study focuses on developing a self-triggered data acquisition system and a noise reduction algorithm for the Multi-gap Resistive Plate Chamber (MRPC) Time-of-Flight Positron Emission Tomography (TOF-PET) system. The system integrates a fast front-end amplifier, a waveform digitization module based on the DRS4 chip, and an efficient noise reduction algorithm to address challenges such as high noise trigger rates and precise gamma-ray detection. The proposed self-triggered system, through threshold discrimination, coincidence logic, and continuous oscillation check, reduces the noise trigger rate to 0.004 Hz. Experimental results show that the system accurately localizes and images the 22Na radioactive source, and has a good time resolution of 162 ps FWHM for 0.511 MeV gamma rays. Copyright © 2025, The Authors. All rights reserved.

关键词： Gamma rays

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Comparative Thermodynamic Analysis of Csnsii Srf System Cooling Scheme Based on Neural Network Optimized by Ssa-Ga

SSRN

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SSRN 2023年

作者： Li, Mei Ge, Rui Xu, Miaofu Chang, Zhengze Sang, Minjing Ye, Rui Sun, Liangrui Ma, Changcheng Li, Penghui Li, Shaopeng He, Feisi Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Key Laboratory of Particle Acceleration Physics & Technology CAS Beijing100049 China Center for Superconducting RF and Cryogenics Institution of High Energy Physics Beijing China

The China Spallation Neutron Source second phase (CSNS-II) accelerator upgrades consist of three major components: linac energy upgrade from 80 MeV to 300 MeV, injection system upgrade, and new magnetic alloy dual harmonic cavities. There are ten double spoke cavities cryomodules and eight elliptical cavities cryomodules in total. A comparative thermodynamic analysis of both types of cooling schemes for superconducting radio frequency (SRF) systems, referred to as Scheme 1 (a cryogenic distribution system with distributed heat exchangers) and Scheme 2 (a cryogenic distribution system with central heat exchangers), was presented in this paper. The length and size of process transfer lines, as well as the heat loads subjected to their components, of cryogenic distribution systems were introduced. In addition, the unsteady state cooldown process for the CSNS-II SRF cryomodules was investigated. The analysis results that included temperature and pressure profiles along the linac distance, as well as distributions of JT expansion effectiveness, mass flow rate, and cryomodule exegetic efficiency. Furthermore, the exergy analysis and refrigeration power are investigated using a neural network optimized by the sparrow search algorithm genetic algorithm (SSA-GA). Results show that, Scheme 1 is more advantageous than Scheme 2 because it can save maintenance time. From 300K to 4.5K, the total cooldown time of SRF cryomodules is approximately 28 hours. The maximum is around 1.1 bara, which can be considered in the acceptable range. The prediction of is stable at the 7th epoch after being optimized by SSA-GA, and the MSE is 1×10-5. And the error between the predicted and true values of the BP neural network after SSA optimization is very small (less than 0.1%), approaching zero, indicating that the BP optimized by SSA achieves good prediction. This paper's work can serve as a solid foundation for the construction and operation of the CSNS-II. © 2023, The Authors. All rights rese

关键词： Genetic algorithms

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Unsteady Numerical Simulation of Cooling Process and Experimental Verification of 1.3ghz 9-Cell Superconducting Cavity Cryomodule Based on Six Different Geometry Structure

SSRN

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SSRN 2023年

作者： Li, Mei Liu, Zhu Ge, Rui Chang, Zhengze Han, Ruixiong Zhu, keyu Zhou, Jianrong Sun, Liangrui Sang, Minjing Ye, Rui Li, Shaopeng Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Key Laboratory of Particle Acceleration Physics & Technology CAS Beijing100049 China Center for Superconducting RF and Cryogenics Institution of High Energy Physics Beijing100049 China

1.3GHz 9-cell superconducting cavity is an indispensable component of European X-ray free electron laser and future ring electron-positron collider, which provides higher acceleration voltage and higher frequency power per unit length, and saves equipment space. Superconducting cavities usually need to be gradually cooled from the ambient temperature (300K) to the superconducting temperature (4.2K or below) during the test and operation. The cooling rates in each stage and the temperature difference on the cavity must be strictly limited to prevent excessive thermal stress on the surface of the superconducting cavity. At present, a less efficient manual control scheme is normally adopted. Low levels of automation, a reliance on the experience of the operation personnel, and a conservatively long period with low efficiency are the main drawbacks of the manual control method. In this paper, 1.3GHz 9-cell superconducting cavity and its helium vessel were taken as the research subjects. Six different mechanical structures were designed, and six different three-dimensional flow-thermal coupling models were established. ANSYS Fluent numerical simulation software was used to analyze the temperature distribution and cooling law for each structural model. The influence of inlet parameters on the cooling process was analyzed, and the appropriate mechanical structure model was recommended. The results showed that: The closer the superconducting cavity is to the inlet during the cooling process, the lower the temperature is. In the early stage of cooling, the rate is faster, and the temperature difference can be reduced by 50% in the first 30 min. After experimental test verification, the total cooling time is about 650 min (10.8h or so), and the deviation between the simulation results and the experimental test results is less than 7%, which shows the simulation results can well predicate the actual cooldown process for 1.3GHz 9-cell superconducting cavity. The research work i

关键词： Cooling

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