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Three Dimensional Simulation of the Steady Solar Wind in Carrington Rotation 1935

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空间科学学报 2006年第1期26卷 8-13页

作者： XIANG changqing feng Xueshang YAO Jiusheng Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080

A three-dimensional MHD simulation is conducted to study the steady solar wind in Carrington Rotation (CR) 1935 by using the three-dimensional numerical magnetohydrodynamic (MHD) model introduced by feng et al The numerical results demonstrate that the neutral current sheet has two peaks and two valleys, which is consistent with the result of PFSS model at Wilcox Solar Observatory (WSO). The obtained proton number density at 2.5 Rs is of the same order of magnitude as the result estimated from K-coronal brightness during the CRs 1733-1742 in 1983 made by Wei et al. The radial velocity profile along heliocentric distance is consistent with that of low solar wind speed deduced by Sheeley and Wang et al. However, it is not able to reproduce the fast-speed flow in coronal holes and slow solar wind in streamers because of oversimplified energy equation adopted in our model. Future efforts must be made to remedy this deficiency.

关键词：三维模拟太阳风空间物理地球物理

A low dead time vernier delay line TDC implemented in an actel flash-based FPGA

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Nuclear Science and Techniques 2013年第4期24卷 61-67页

作者： QIN Xi feng changqing ZHANG Deliang ZHAO Lei LIU Shubin AN Qi State Key Laboratory of Particle Detection and Electronics University of Science and Technology of China Department of Modern Physics University of Science and Technology of China

In this paper,a high precision vernier delay line(VDL) TDC(Time-to-Digital Convertor) in an actel flash-based Field-Programmable-Gate-Arrays A3PE1500 is implemented,achieving a resolution of 16.4-ps root mean square value or 42-ps averaged bin *** TDC has a dead time of about 200 ns while the dynamic range is 655.36 μ*** double delay lines method is employed to cut the dead time in half to improve its *** the bin size of the TDC is dependent on temperature,a compensation algorithm is adopted as temperature drift correction,and the TDC shows satisfying performance in a temperature range from –5℃ to +55℃.

关键词： Flash Actel 死区时间延迟线 FPGA 游标基础香港贸易发展局

Waveform digitization utilizing switched-capacitor arrays

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Nuclear Science and Techniques 2012年第2期23卷 109-113页

作者： WANG Jinhong ZHAO Lei feng changqing LIU Shubin AN Qi State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Anhui Key Laboratory of Physical Electronics Department of Modern PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Compared with traditional waveform digitization with flash-ADCs, waveform digitization with switched-capacitor arrays (SCAs) is able to achieve the sampling speed above 1 GS/s without degrading the analog to digital conversion precision significantly. In this paper, we present the implementation of a fast waveform digitization system with the use of SCAs, and evaluate its performance of waveform digitization and the waveform timing. At about 5 GS/s, the dynamic input range of the digitizer is about 66 dB, and its timing precision is about 20 ps (RMS).

关键词：波形数字化开关电容阵列数字化系统数字化波形数字转换器转换精度采样速度执行情况

Clock and data alignment scheme for readout electronics prototype of PandaX-nT

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Radiation Detection Technology and Methods 2021年第2期5卷 161-167页

作者： Shuo Wang Zhongtao Shen Shuwen Wang changqing feng Shubin Liu State Key Laboratory of Particle Detection and Electronics(IHEP-USTC) Hefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

Purpose This work proposes a clock and data alignment scheme for the readout electronics system of the future PandaX-nT dark matter detection *** the waveform information of the photomultiplier signal is obtained by accumulating all acquisition channels of the front-end digitization module(FDM),it is required that each FDM acquisition channel should be *** The readout electronics system is composed of a clock distribution module,64 FDMs,and 4 data acquisition(DAQ)*** multi-board synchronous acquisition circuit can provide the same REF CLOCK and SYSREF signal for multiple FDMs boards to ensure the alignment of the sampled data collected by the analog-to-digital *** data aggregation circuit can ensure that the sampled data of multiple FDM boards are aligned with each other when they are aggregated to the DAQ *** and conclusions The functional verification test results show that the synchronization between the prototype electronics channels is less than 80 ps,thus enabling to meet the requirements of the readout electronics prototype of PandaX-nT.

关键词： Dark matter detection PandaX-nT Readout electronics system Synchronization

Design of the FPGA-based gigabit serial link for PandaX-III prototype TPC

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Radiation Detection Technology and Methods 2017年第2期1卷 113-116页

作者： Cheng Li changqing feng Jianing Dong Danyang Zhu Shubin Liu Qi An State Key Laboratory of Particle Detection and Electronics Hefei 230026China University of Science and Technology of China Hefei 230026China

Background:PandaX-III is aimed to search for neutrinoless double beta decay of 136Xe at China Jinping Underground *** test various design features of PandaX-III detector,a prototype TPC with 20 kg Xe containing inside is ***:Front-end boards installed inside the waterproof vessel integrate charge of Micromegas signal,digitize signal waveform and send data packet to back-end *** boards receive synchronous information(global clock,global trigger,etc.),as well as command messages from back-end *** order to satisfy the requirement of high data throughput and multiple types of synchronous data transmission,we propose an optical fiber link to communicate between front-end board and back-end ***:Communication of serial transmission is performed using FPGA-based gigabit transceiver with a 1 Gbit/s point-to-point speed.A dedicated user-defined protocol is implemented for various kinds of data ***:To validate the performance of this link,bit error rate and eye diagram were *** joint test with detector was conducted in *** test results showed sufficient data bandwidth and stable ***:To satisfy the requirement for data transmission between front-end board and back-end board in PandaX-III TPC detector readout,an FPGA-based gigabit serial link is designed and *** design shows good performance and will be applied to the R&D of PandaX-III TPC.

关键词： Gigabit transceiver TPC Micromegas PandaX-III

A SKIROC2-based prototype electronics system for silicon PIN array

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Radiation Detection Technology and Methods 2018年第2期2卷 31-37页

作者： Siyuan Ma Shubin Liu Hao Liu Zihang Fang Cheng Li changqing feng Qi An State Key Laboratory of Particle Detection and Electronics Hefei 230026China University of Science and Technology of China Hefei 230026China

Background Silicon PIN(Si-PIN)diode has been widely used in high-energy physics *** next-generation experiments ask for a large amount of the Si-PIN diode arrays,leading to a requirement for the electronics system with features of higher integration and lower power consumption than the traditional *** The aim was to design and implement a prototype of multi-channel electronic system,which is based on the SKIROC2 *** system is also considered as the pre-research of the silicon–tungsten(Si-W)ECAL for *** The prototype is divided into two parts,so that it has the potentiality for the expansion of more readout *** front-end board(FEB),which carries a Si-PIN diode array and an ASIC of SKIROC2 on it,provides high voltage to the Si-PIN diodes and processes the signals as *** FEB is configured by a data interface board(DIF)and sends data to the DIF,which then transfers data to PC via USB interface after packing *** The prototype electronics system has been *** equivalent noise level of all the 64 channels is below 0.4 *** dynamic range is up to+3000 fC with an integral nonlinearity(INL)of 0.2%,and the gain non-uniformity is better than 5%.The energy resolution with 59 keV X-rays from 241Am is about 13.3%(in RMS),while the signal-to-noise ratio(SNR)reaches about 10.9 for minimum ionizing particles(MIPs).Conclusion In this paper,a SKIROC2-based prototype electronics system for Si-PIN array,as well as the performance test,has been *** system has features of high integration,low noise,and high dynamic *** SKIROC2,as well as the design concept of the electronics system,can be applied to the preliminary prototype Si-W ECAL of CEPC.

关键词： SKIROC2 Silicon PIN diode Front-end electronics Readout system

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Mg97Zn1Y2镁合金的高温磨损行为

机械工程学报 2019年第24期55卷 66-71页

作者：冯昌青赵伟孙元安健吉林大学材料科学与工程学院长春130022 吉林大学公共计算机教学与研究中心长春130022

对Mg97Zn1Y2合金的室温磨损行为已有研究,但是缺乏高温磨损研究,探究该合金高温磨损行为是非常必要的。采用MG-2000型销-盘磨损试验机对Mg97Zn1Y2合金进行磨损试验,试验温度范围为20~200℃,加载范围为20~320N,探究不同温度以及载荷对Mg9... 详细信息

对Mg97Zn1Y2合金的室温磨损行为已有研究,但是缺乏高温磨损研究,探究该合金高温磨损行为是非常必要的。采用MG-2000型销-盘磨损试验机对Mg97Zn1Y2合金进行磨损试验,试验温度范围为20~200℃,加载范围为20~320N,探究不同温度以及载荷对Mg97Zn1Y2合金磨损行为的影响。根据试验数据绘制不同温度下的磨损率曲线;应用SEM观察磨损表面形貌,应用EDS分析磨损表面的化学成分,划分磨损区间。结果表明:随着温度的升高,Mg97Zn1Y2合金的磨损率随载荷的增加而上升得更加显著,磨损行为可以分为轻微磨损和严重磨损两个阶段:轻微磨损阶段的磨损机制为:磨粒磨损、剥层磨损、氧化磨损;严重磨损阶段为严重的塑性变形和表面熔化。绘制了磨损机制转变图,划分该合金的安全工作区间,为该合金在高温下的摩擦学应用提供有益参考。

关键词：镁合金高温磨损磨损机制磨损转变图

A comparative study on 3-D solar wind structure observed by Ulysses and MHD simulation

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Science Bulletin 2005年第7期50卷 672-678页

作者： feng Xueshang, XIANG changqing, ZHONG Dingkun & FAN Quanlin SIGMA Weather Group, Key Laboratory of Space Weather Key Labo- ratory of Geospace Environment and Geodesy, Ministry of Education, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, China SIGMA Weather Group Key Laboratory of Space Weather Beijing China Key Labo-ratory of Geospace Environment and Geodesy Ministry of Education Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

During Ulysses’ first rapid pole-to-pole transit from September 1994 to June 1995, its observations showed that middle- or high-speed solar winds covered all latitudes except those between ?20° and +20° near the ecliptic plane, where the velocity was 300―450 km/s. At poleward 40°, however, only fast solar winds at the speed of 700―870 km/s were observed. In addition, the transitions from low-speed wind to high-speed wind or vice versa were abrupt. In this paper, the large-scale structure of solar wind observed by Ulysses near solar minimum is simulated by using the three-dimensional numerical MHD model. The model com- bines TVD Lax-Friedrich scheme and MacCormack II scheme and decomposes the calculation region into two re- gions: one from 1 to 22 Rs and the other from 18 Rs to 1 AU. Based on the observations of the solar photospheric magnetic field and an addition of the volumetric heating to MHD equations, the large-scale solar wind structure mentioned above is reproduced by using the three-dimensional MHD model and the numerical results are roughly consistent with Ulysses’ observations. Our simulation shows that the initial magnetic field topology and the addition of volume heating may govern the bimodal structure of solar wind observed by Ulysses and also demonstrates that the three-dimensional MHD numerical model used here is efficient in modeling the large-scale solar wind structure.

关键词： Ulysses observation solar wind structure numerical simulation.

A low-energy ion spectrometer with half-space entrance for three-axis stabilized spacecraft

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Science China(Technological Sciences) 2019年第6期62卷 1015-1027页

作者： HU RenXiang SHAN Xu YUAN GuangYuan WANG ShuWen ZHANG WeiHang QI Wei CAO Zhe LI YiRen CHEN ManMing YANG XiaoPing WANG Bo SHAO SiPei LI feng ZHONG XiaoQing FAN Dan HAO XinJun feng changqing SU ZhenPeng SHEN ChengLong LI Xin DAI GuYue QIU BingLin PAN ZongHao LIU Kai XU ChunKai LIU ShuBin AN Qi ZHANG TieLong WANG YuMing CHEN XiangJun Hefei National Laboratory for Physical Sciences at the Microscale Department of Modern Physics University of Science and Technology of China Hefei 230026 China State Key Laboratory of Particle Detection and Electronics (IHEP-USTC) Department of Modern Physics University of Science and Technology of China Hefei 230026 China CAS Key Laboratory of Geospace Environment School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Shandong Institute of Space Electronic Technology Yantai 264003 China Institute of Telecommunication Satellite China Academy of Space Technology Beijing 100094 China

A low-energy ion spectrometer(LEIS) for use aboard three-axis stabilized spacecraft has been developed to measure ion energy per charge distribution in three-dimensional space with good energy-, angular-and temporal-resolutions. For the standard top-hat electrostatic analyzer used widely in space plasma detection, three-axis stabilized spacecraft makes it difficult to obtain complete coverage of all possible ion arrival directions. We have designed angular scanning deflectors supplementing to a cylindrically symmetric top-hat electrostatic analyzer to provide a half-space field of view as 360°×90°(–45°–+45°), and fabricated the LEIS flight model for detecting magnetospheric ions in geosynchronous orbit. The performance of this payload has been evaluated in detail by a series of simulation and environmental tests, and the payload has also been calibrated through laboratory experiments using a low-energy ion source. The results show that capabilities of the LEIS payload are in accordance with the requirements of a magnetospheric mission.

关键词： low-energy ion spectrometer three-dimensional measurement top-hat electrostatic analyzer angular scanning deflectors simulation ground calibration