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Electronics system for the cosmic X-ray polarization detector

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Nuclear Science and Techniques 2023年第5期34卷 1-12页

作者： Hui Wang Dong Wang Ran Chen Yan-Wei Kui Hong-Bang Liu Zong-Wang Fan Huan-Bo Feng Jin Li Jun Liu Qian Liu Shi Chen Yuan-Kang Yang Zhuo Zhou Zi-Li Li Shi-Qiang Zhou Ni Fang PLAC Key Laboratory of Quark&Lepton Physics(MOE)Central China Normal UniversityWuhan 430079China Guangxi key laboratory for Relativistic astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China key laboratory of particle astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physical Science University of Chinese Academy of SciencesBeijing 100049China School of Science Huzhou UniversityHuzhou 313000China

This study presents an electronics system for cosmic X-ray polarization detection(CXPD).The CXPD was designed as a high-sensitivity soft X-ray polarimeter with a measurement energy range of 2-10 keV carried by a CubeSat.A stable and functionally complete electronics system under power and space constraints is a key *** complete CXPD electronics system(CXPDES)comprises hardware and *** adopts a three-layer electronic board structure based on functionality and available *** gas pixel detectors(GPDs)were placed on the top layer board,and CXPDES provided the GPDs with voltages up to-4000 *** GPD signal was digitized,compressed,encoded,and stored before being transmitted to the *** CXPDES provided stable and high-speed communication based on a scheme that separated command and data transmission,and it supports the CXPDES in-orbit *** addition,environmental monitors,silicon photomultiplier(SiPM)triggers,power management,GPDs configuration,and mode switches were included in the overall operating logic of the *** results obtained by testing the CXPDES showed that it satisfied all the requirements of *** CXPDES provides design experience and technological readiness for future large-area X-ray polarimetry missions.

关键词： X-ray polarimeter Electronics CubeSat Gas pixel detector FPGA

Classifying cosmic-ray proton and light groups in LHAASO-KM2A experiment with graph neural network

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Chinese Physics C 2020年第6期44卷 133-142页

作者： Chao Jin Song-zhan Chen Hui-hai He key laboratory of particle astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences 19 A Yuquan RdShijingshan DistrictBeijing 100049China

The precise measurement of cosmic-ray(CR) knees of different primaries is essential to reveal CR acceleration and propagation mechanisms, as well as to explore new physics. However, the classification of CR components is a difficult task, especially for groups with similar atomic numbers. Given that deep learning achieved remarkable breakthroughs in numerous fields, we seek to leverage this technology to improve the classification performance of the CR Proton and Light groups in the LHAASO-KM2A experiment. In this study, we propose a fused graph neural network model for KM2A arrays, where the activated detectors are structured into graphs. We find that the signal and background are effectively discriminated in this model, and its performance outperforms both the traditional physicsbased method and the convolutional neural network(CNN)-based model across the entire energy range.

关键词： cosmic ray knee graph neural network

First lattice QCD calculation of semileptonic decays of charmed-strange baryonsΞc

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Chinese Physics C 2022年第1期46卷 12-20页

作者： Qi-An Zhang Jun Hua Fei Huang Renbo Li Yuanyuan Li Caidian Lü Peng Sun Wei Sun Wei Wang Yibo Yang key laboratory for particle astrophysics and Cosmology(MOE) Shanghai Key Laboratory for Particle Physics and CosmologyTsung-Dao Lee InstituteShanghai Jiao Tong UniversityShanghai 200240China INPAC Key Laboratory for Particle Astrophysics and Cosmology(MOE)Shanghai Key Laboratory for Particle Physics and CosmologySchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Nanjing Normal University Nanjing 210023China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China School of Physics University of Chinese Academy of SciencesBeijing 100049China CAS key laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/HangzhouChina

While the standard model is the most successful theory to describe all the interactions and constituents of elementary particle physics,it has been constantly scrutinized for over four *** decays of charm quarks can be used to measure the coupling strength between quarks in different families and serve as an ideal probe for CP *** the lowest charm-strange baryons with three different flavors,Ξ;baryons(composed of csu or csd)have been extensively studied in *** this study,we use state-of-the-art lattice QCD techniques to generate 2+1 clover fermion ensembles with two lattice spacings,a=(0.108,0.080 fm).Then,we present the first ab-initio lattice QCD calculation of the Ξ;→Ξ form *** theoretical results for the Ξc→Ξl;v;decay widths are consistent with and approximately two times more precise than the latest measurements by the ALICE and Belle *** on the latest experimental measurements,we independently obtain the quark-mixing matrix element |V;|,which is in good agreement with results from other theoretical approaches.

关键词： Ξc semileptonic decays lattice QCD form factors CKM matrix elements

Modeling the evolution and distribution of the frequency's second derivative and the braking index of pulsar spin

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Research in Astronomy and astrophysics 2015年第7期15卷 963-974页

作者： Yi Xie Shuang-Nan Zhang Jin-Yuan Liao National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences key laboratory of particle astrophysics Institute of High Energy Physics Chinese Academy of Sciences Physics Department University of Alabama in Huntsville

We model the evolution of the spin frequency＇s second derivative ν¨ and the braking index n of radio pulsars with simulations within the phenomenological model of their surface magnetic field evolution, which contains a long-term power-law decay modulated by short-term oscillations. For the pulsar PSR B0329＋54, a model with three oscillation components can reproduce its ν¨ variation. We show that the ＂averaged＂ n is different from the instantaneous n, and its oscillation magnitude decreases abruptly as the time span increases, due to the ＂averaging＂ effect. The simulated timing residuals agree with the main features of the reported data. Our model predicts that the averaged ν¨ of PSR B0329＋54 will start to decrease rapidly with newer data beyond those used in Hobbs et al. We further perform Monte Carlo simulations for the distribution of the reported data in ｜ν¨｜ and ｜n｜ versus characteristic age τ*** is found that the magnetic field oscillation model with decay index α = 0 can reproduce the distributions quite well. Compared with magnetic field decay due to the ambipolar diffusion（α = 0.5） and the Hall cascade（α = 1.0）, the model with no long term decay（α = 0） is clearly preferred for old pulsars by the p-values of the two-dimensional Kolmogorov-Smirnov test.

关键词： stars: neutron -- pulsars: individual (B0329+54) -- pulsars: general --magnetic fields

Near-Earth Asteroids as the Parents of the δ-Cancrid Meteoroid Stream

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Research in Astronomy and astrophysics 2024年第12期24卷 13-25页

作者： G.I.Kokhirova M.Zhang X.-G.Li A.I.Zhonmuhammadi X.Liu Institute of astrophysics National Academy of Sciences of Tajikistan Xinjiang Astronomical Observatory Chinese Academy of Sciences key laboratory for Radio Astronomy Chinese Academy of Sciences Xinjiang key laboratory of Radio astrophysics University of Chinese Academy of Sciences

The δ-Cancrid meteoroid stream forms four active meteor showers which are observable on the Earth annually during January–February and August–September. The stream's definite parent comet has not been established. We performed a search for near-Earth asteroids(NEAs) associated with this stream. We have followed the backward evolution of the orbital elements of a sample of NEAs and found their orbits at the Earth-crossing positions. Using these orbits, we calculated the theoretical parameters of meteor showers associated with the considered NEAs. We carried out our search for observable active showers that match theoretically predicted ones with published data,and the result turned out that the predicted meteor showers of 13 NEAs were identified with the active showers produced by the δ-Cancrid meteoroid stream. The comet-like orbits of NEAs and established association with active meteor showers indicate their common cometary origin. The NEAs considered are moving within the stream and likely represent the dormant remnants of a parent comet of the δ-Cancrid asteroid-meteoroid complex that disintegrated more than 12 thousand years ago.

关键词： asteroids comets: general meteorites meteoroids meteors minor planets δ-Cancrids

F-μbond length andμSR depolarization spectrum calculation for fluoride using two-component density functional theory

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Chinese Physics B 2023年第8期32卷 120-123页

作者：潘智康邓力潘子文原钺张宏俊叶邦角 State key laboratory of particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China

First-principles calculation of muons in ionic fluorides has been proposed ***,there is a considerable difference between the obtained F-μbond length and the experimental data obtained by muon spin relaxation(μSR).Considering that the difference may be caused by ignoring the quantum effect of muons,we use two-component density functional theory(TCDFT)to consider the quantized muon and recalculate the bond length and theμSR depolarization *** testing several muon-electron correlation,we show that TCDFT can give better results than the commonly used“DFT+μ”.

关键词： muon spin relaxation/rotation fluoride density-functional theory

Fidelity susceptibility and geometric phase in critical phenomenon

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Chinese Physics B 2011年第4期20卷 38-43页

作者：田立君朱长青张宏标秦立国 Department of Physics Shanghai University Shanghai key laboratory for astrophysics Institute of Theoretical Physics Northeast Normal University

Motivated by recent developments in quantum fidelity and fidelity susceptibility, we study relations among Lie algebra, fidelity susceptibility and quantum phase transition for a two-state system and the Lipkin-Meshkov Glick model. We obtain the fidelity susceptibilities for SU（2） and SU（1, 1） algebraic structure models. From this relation, the validity of the fidelity susceptibility to signal for the quantum phase transition is also verified in these two systems. At the same time, we obtain the geometric phases in these two systems by calculating the fidelity susceptibility. In addition, the new method of calculating fidelity susceptibility is used to explore the two-dimensional XXZ model and the Bose-Einstein condensate （BEC）.

关键词： fidelity susceptibility geometric phase quantum phase transition

An industrial CT system for monitoring a running aero-engine

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Nuclear Science and Techniques 2014年第6期25卷 24-30页

作者：常铭肖永顺陈志强 Department of Engineering Physics Tsinghua University key laboratory of particle & Radiation Imaging Tsinghua University

In order to improve aerodynamic performance and efficiency, monitoring the geometry and position information of the internal structure with the aero-engine under various operational statuses is an important task. In this paper, a novel design of industrial computed tomography(ICT) system with a linac as X-ray source is proposed to complete the task. The major advantage of the proposed system is that it can provide visualized images of internal structures of the running aero-engine without physical disturbance, which makes it possible to extract the accurate geometry information. The main idea behind this design is to measure the projection data from various views for reconstructions making use of the rotations of the aero-engine blades, instead of the mechanical rotations in the conventional ICT system. However, due to high speed rotation of the aero-engine blades,the system faces more challenges than conventional ICT systems both in data acquisitions and reconstruction algorithms. The challenges and corresponding solutions are presented in this paper. In conclusion, the proposed ICT system provides a powerful tool for monitoring the running aero-engines.

关键词：航空发动机叶片工业CT系统运行工业计算机断层扫描空气动力性能信息通信系统内部结构线性加速器

TW Laser system for Thomson scattering X-ray light source at Tsinghua University

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Chinese Physics C 2009年第S2期33卷 154-156页

作者：颜立新杜应超杜强李任恺华剑飞黄文会唐传祥 Accelerator laboratory Department of Engineering Physics key laboratory of particle & Radiation Imaging Ministry of Education Tsinghua University

A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radiofrequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

关键词： Thomson scattering TW laser photocathode RF gun