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Transverse mode-coupling instability with longitudinal impedance

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Nuclear Science and Techniques 2024年第6期35卷 40-53页

作者： Hai-Sheng Xu Chun-Tao Lin Na Wang Jing-Ye Xu Yuan Zhang Key laboratory of particle acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China Institute of Advanced Science Facilities Shenzhen 518107GuangdongChina

Transverse mode-coupling instability(TMCI)is a dangerous transverse single-bunch instability that can lead to severe par-ticle *** mechanism of TMCI can be explained by the coupling of transverse coherent oscillation modes owing to the transverse short-range wakefield(i.e.,the transverse broadband impedance).Recent studies on future circular colliders,e.g.,FCC-ee,showed that the threshold of TMCI decreased significantly when both longitudinal and transverse impedances were *** performed computations for the circular electron-positron collider(CEPC)and observed a similar *** studies on the influence of longitudinal impedance on the TMCI threshold were *** concluded that the imaginary part of the longitudinal impedance,which caused a reduction in the incoherent synchrotron tune,was the primary reason for the reduction in the TMCI ***,the real part of the longitudinal impedance assists in increasing the TMCI threshold.

关键词： Transverse mode-coupling instability Longitudinal impedance

Milestone progress of the HEPS booster commissioning

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Nuclear Science and Techniques 2024年第1期35卷 170-177页

作者： Yue-Mei Peng Jian-She Cao Jin-Hui Chen Hai-Yi Dong Ping He Yi Jiao Ling Kang Wen Kang Jian Li Jing-Yi Li Guo-Ping Lin Fang Liu Feng-Li Long Cai Meng Xin Qi Hua-Min Qu Yan-Feng Sui Sheng Wang Gang Xu Qiang Ye Jing Zhang Pei Zhang Wei-Min Pan Key laboratory of particle acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadShijingshan DistrictBeijing 100049China University of the Chinese Academy of Sciences 19A Yuquan RoadShijingshan DistrictBeijing 100049China

The high-energy photon source(HEPS)is the first fourth-generation synchrotron light source facility in *** HEPS injector consists of a linear accelerator(Linac)and a full energy *** booster captures the electron beam from the Linac and increases its energy to the value required for the storage *** full-energy beam could be injected to the storage ring directly or after“high-energy accumulation.”On November 17,2023,the key booster parameters successfully reached their corresponding target *** milestone results were achieved based on numerous contributions,including nearly a decade of physical design,years of equipment development and installation,and months of beam *** measured at the extraction energy of 6 GeV,the averaged beam current and emittance reached 8.57 mA with 5 bunches and 30.37 nm rad with a single-bunch charge of 5.58 nC,compared with the corresponding target values of 6.6 mA and 35 nm rad,*** paper presents the physical design,equipment development,installation,and commissioning process of the HEPS booster.

关键词： High energy photon source Booster Beam commissioning

An integrative mathematical model of microwave ion thruster for mHz-frequency thrust noise analysis

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Chinese Journal of Aeronautics 2024年第4期37卷 121-136页

作者： Xiang NIU Hui LIU Daren YU plasma Propulsion laboratory Harbin Institute of TechnologyHarbin 150001China

Many high-precision space missions need thrusters to produce thrust with low noise to compensate for disturbances and ensure satellite platform stability. Microwave ion thruster is characterized with a wide thrust range and potential for these missions. A cost-effective and accurate mathematical model is crucial for mHz-frequency thrust noise analysis and feedback controller design. The particle-In-Cell(PIC) and global models are two common simulation tools. The PIC model is characterized with high accuracy but huge computation cost, which is difficult to analyze long-time performance characteristics. Now, the global model is only used for the discharge chamber with low accuracy and cannot reflect ion extraction properties. In this paper, an integrative mathematical model is built for a 1-cm microwave ion thruster and can reflect ion beamlet divergence and impingement on the Accelerator Grid(AG). Simulation results show good agreement with experiments at 0.06 sccm. However, the model demonstrates worse consistency with experiments when the flux increases to 0.1 sccm, which may be because the influence of neutral gas on the Electron Cyclotron Resonance(ECR) is not considered in the model. A long-time(1000 s) simulation is conducted with this model under 35 μN. It takes 3 hrs, and the thrust noise reaches 1 μN/Hz^(0.5) at 1 mHz.

关键词： Electric propulsion Microwave ion thruster Integrative model Sheath property Ion beamlet divergence Thrust noise plasma

Optimized online filter stack spectrometer for ultrashort X-ray pulses

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Nuclear Science and Techniques 2024年第5期35卷 85-98页

作者： Jia-Xing Wen Ge Ma Ming-Hai Yu Yu-Chi Wu Yong-Hong Yan Shao-Yi Wang Huai-Zhong Gao Lu-Shan Wang Yu-Gang Zhou Qiang Li Yue Yang Fang Tan Xiao-Hui Zhang Jie Zhang Wen-Bo Mo Jing-Qin Su Wei-Min Zhou Yu-Qiu Gu Ming Zeng Zong-Qing Zhao Science and Technology on plasma Physics laboratory Laser Fusion Research CenterCAEPMianyang 621900China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key laboratory of particle and Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China School of Information Engineering Southwest University of Science and TechnologyMianyang 621010China

Currently,with the advent of high-repetition-rate laser-plasma experiments,the demand for online diagnosis for the X-ray spectrum is increasing because the laser-plasma-generated X-ray spectrum is very important for characterizing electron dynamics and *** this study,scintillators and silicon PIN(P-type–intrinsic-N-type semiconductor)diodes were used to construct a wideband online filter stack *** X-ray sensor and filter arrangement was optimized using a genetic algorithm to minimize the condition number of the response ***,the unfolding error was significantly reduced based on numerical *** detector responses were quantitatively calibrated by irradiating the scintillator and PIN diode with various nuclides and comparing the measuredγ-ray peaks.A prototype 15-channel spectrometer was developed by integrating an X-ray detector with front-and back-end *** prototype spectrometer could record X-ray pulse signals at a repetition rate of 1 ***,an optimized spectrometer was employed to record the real-time spectra of laser-driven bremsstrahlung *** optimized spectrometer offers a compact solution for spectrum diagnostics of ultrashort X-ray pulses,exhibiting improved accuracy in terms of spectrum measurements and repetition rates,and could be widely used in next-generation high-repetition-rate high-power laser facilities.

关键词： Filter stack spectrometer Laser plasma diagnostics X-ray diagnostics Scintillator PIN diode

Revisiting the spin effects induced by thermal vorticity

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Chinese Physics C 2024年第5期48卷 194-208页

作者：高建华杨诗正 Shandong Key laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and PhysicsShandong UniversityWeihai 264209China Institute of Frontier and Interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation(MOE)Shandong UniversityQingdao 266237China

We revisit the spin effects induced by thermal vorticity by calculating them directly from the spin-dependent distribution *** spin-1/2 particles,we provide the polarization up to the first order of thermal vorticity and compare it with the usual results calculated from the spin *** spin-1 particles,we show that all the non-diagonal elements vanish and there is no spin alignment up to the first order of thermal *** present the spin alignment at second-order contribution from thermal *** also show that the spin effects for both Dirac and vector particles receive an extra contribution when the spin direction is associated with the momentum of the particle.

关键词： relativistic heavy ion collisions global polarization quark gluon plasma

Theoretical investigations of population trapping phenomena in atomic four-color,three-step photoionization scheme

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Chinese Physics B 2024年第3期33卷 333-340页

作者：卢肖勇孙亚鹏 Science and Technology on particle Transport and Separation laboratory Tianjin 300180China Department of Engineering Physics Tsinghua UniversityBeijing 100084China

The four-color three-step selective photoionization process of atom is very important in laser isotope separation *** population trapping phenomena and their influences are studied theoretically in monochromatic and non-monochromatic laser fields based on the density matrix theory in this *** evolutions of the photoionization properties of the four-color,three-step process are *** population trapping effects occur intensely in monochromatic excitation,while it gradually turns weak as the laser bandwidth *** effects of bandwidth,Rabi frequency,time delay,and frequency detuning on the population trapping effect are investigated in monochromatic and non-monochromatic laser *** effects of laser process parameters and atomic parameters on the effective selective photoionization are also *** ionization probability and selectivity factors,as evaluation indexes,are difficult to improve synchronously by adjusting systematic ***,the existence of metastable state may play a negative role when its population is low enough.

关键词： population trapping metastable state selective photoionization laser bandwidth

Complexity growth in a holographic QCD model

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Chinese Physics C 2024年第3期48卷 142-147页

作者：常文彬侯德富 Institute of particle Physics and Key laboratory of Quark and Lepton Physics(MOS) Central China Normal UniversityWuhan 430079China

In this study,we utilize the complexity-action duality to study the evolution of complexity in a holographic QCD model at finite temperature and chemical *** inserting a fundamental string as a probe,we investigated the properties of complexity growth in this Einstein-Maxwell-scalar gravity system,which is affected by the string velocity,chemical potential,and *** results show that the complexity growth is maximized when the probe string is stationary,and it decreases as the velocity of the string *** the string approaches relativistic velocities,the complexity growth always increases monotonically with respect to the chemical ***,we find that the complexity growth can be used to identify phase transitions and crossovers in the model.

关键词： AdS/CFT holographic QCD model complexity growth

Detector performance of the Gamma-ray Transient Monitor onboard DRO-A satellite

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 75-90页

作者： Pei-Yi Feng Zheng-Hua An Da-Li Zhang Chen-Wei Wang Chao Zheng Sheng Yang Shao-Lin Xiong Jia-Cong Liu Xin-Qiao Li Ke Gong Xiao-Jing Liu Min Gao Xiang-Yang Wen Ya-Qing Liu Xiao-Yun Zhao Fan Zhang Xi-Lei Sun Hong Lu Key laboratory of particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China State Key laboratory of particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

The Gamma-ray Transient Monitor(GTM) is an all-sky monitor onboard the Distant Retrograde Orbit-A(DRO-A) satellite with the scientific objective of detecting gamma-ray transients ranging from 20 ke V to 1 MeV. The GTM was equipped with five Gamma-ray Transient Probe(GTP) detector modules utilizing a NaI(Tl) scintillator coupled with a SiPM array. To reduce the SiPM noise, GTP uses a dedicated dual-channel coincident readout design. In this work, we first studied the impact of different coincidence times on the detection efficiency and ultimately selected a 0.5 μs time coincidence window for offline data processing. To test the performance of the GTPs and validate the Monte-Carlo-simulated energy response, we conducted comprehensive ground calibration tests using the Hard X-ray Calibration Facility(HXCF) and radioactive sources, including the energy response, detection efficiency, spatial response, bias-voltage response, and temperature dependence. We extensively present the ground calibration results and validate the design and mass model of the GTP detector, thus providing the foundation for in-flight observations and scientific data analysis.

关键词： NaI(Tl)detector energy response ground calibration gamma-ray detector DRO-A satellite

Enhancing CO_(2) transport with plasma-functionalized ionic liquid membranes

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plasma Science and Technology 2024年第7期26卷 74-81页

作者：舒茹晨许卉裴晨霄王楠刘新刚侯剑源袁圆张仁熙 Shanghai Key laboratory of Atmospheric particle Pollution and Prevention(LAP) Institute of Environmental ScienceFudan UniversityShanghai 200433People’s Republic of China

The ionic liquid(IL) 1-butyl-3-methylimidazolium tetrafluoroborate treated with radiofrequency plasma is proposed for functionalization and immobilization on polyethersulfone supports to form supported ionic liquid membranes for CO_(2) *** effects of treatment time and transmembrane pressure difference on CO_(2) permeance were *** best gas permeation performance was obtained with a treatment time of 10 min and the transmembrane pressure difference was 0.25 *** of the materials by Fourier transform infrared spectroscopy,x-ray photoelectron spectroscopy and nuclear magnetic resonance spectroscopy demonstrates that the IL is grafted with carboxyl groups and deprotonated through plasma treatment.A preliminary mechanism for the plasma treatment and facilitated transport of CO_(2)has been proposed on this basis.

关键词： ionic liquids carbon dioxide supported ionic liquid membranes facilitated transport radiofrequency plasma