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Design and high-power testing of offline conditioning cavity for CiADS RFQ high-power coupler

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Nuclear Science and Techniques 2024年第9期35卷 18-27页

作者： Ruo-Xu Wang Yuan He Long-Bo Shi Chen-Xing Li Zong-Heng Xue Tian-Cai Jiang Xian-Bo Xu Lie-Peng Sun Zhou-Li Zhang institute of Modern physics Chinese Academy of SciencesLanzhou 730000China lanzhou University Lanzhou 730000China

To validate the design rationality of the power coupler for the RFQ cavity and minimize cavity contamination,we designed a low-loss offline conditioning cavity and conducted high-power *** offline cavity features two coupling ports and two tuners,operating at a frequency of 162.5 MHz with a tuning range of 3.2 *** the installation angle of the coupling ring and the insertion depth of the tuner helps minimize cavity *** performed electromagnetic structural and multiphysics simulations,revealing a minimal theoretical power loss of 4.3%.However,when the cavity frequency varied by110 kHz,theoretical power losses increased to10%,necessitating constant tuner adjustments during *** simulations indicated that increased cavity temperature did not affect frequency *** completion of the offline high-power conditioning platform,we measured the transmission performance,revealing a power loss of 6.3%,exceeding the theoretical *** utilized efficient automatic range scanning and standing wave resonant *** fully condition the power coupler,a 15°phase difference between two standing wave points in the condition-ing system was ***,the maximum continuous wave power surpassed 20 kW,exceeding the expected target.

关键词： RFQ cavity Power coupler Offline conditioning Resonant cavity

Study on the thermo-hydraulic behaviors of the new-pattern fuel assembly in lead-based fast reactors based on OpenFOAM

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Nuclear Science and Techniques 2024年第10期35卷 250-263页

作者： Yun-Xiang Li Run-Sheng Yang Yue Li Xing-Kang Su Zi-Nan Huang Lu Meng Song Li Bin Xi You-Peng Zhang Lu Zhang Wei Jiang institute of Modern physics Fudan UniversityShanghai 200433China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China institute of Modern physics Chinese Academy of SciencesLanzhou 730000China

To improve the heat transfer efficiency of the coolant in lead-based fast reactors,this study optimized the configuration and rotational direction of the spacer wires in fuel assemblies to design a new-pattern fuel *** study conducted detailed comparisons between traditional and new pattern fuel assembly rod bundles utilizing the open-source computational fluid dynamics platform,*** results indicated that the new design may significantly reduce the pressure drop along the rod bundle,which is beneficial for lowering the pressure ***,this new design improved coolant mixing in the subchannels,which facilitated a more uniform temperature distribution and lower thermal gradients at the assembly *** factors collectively reduced the thermal fatigue and creep in nearby internal ***,the newpattern fuel assembly proposed in this study may have better heat transfer performance,thereby enhancing the Integrated Thermal-Hydraulic Factor by 48.2% compared to the traditional pattern.

关键词： Spacer wires Enhanced coolant mixing OpenFOAM CFD simulations

Thermodynamic nature of black holes in coexistence region

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Science China(physics,Mechanics & Astronomy) 2024年第5期67卷 27-32页

作者： Shao-Wen Wei Yu-Xiao Liu lanzhou Center for Theoretical physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of Mo ELanzhou UniversityLanzhou 730000China institute of Theoretical physics&Research Center of Gravitation Lanzhou UniversityLanzhou 730000China

Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic ***,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of *** at these coexistence states,in this work,we develop a general approach by introducing two new ratio *** first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule *** demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase *** study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and *** results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.

关键词： transition. state. thermodynamic

Masses and decays of triply-heavy pentaquarks

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Chinese physics C 2024年第10期48卷 137-149页

作者： Chang-Le Liu Wen-Xuan Zhang Duo-Jie Jia institute of Theoretical physics College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070China General Education Center Qinghai Institute of TechnologyXining 810000China lanzhou Center for Theoretical physics Lanzhou UniversityLanzhou 730000China

In this study,we analyzed masses and decays of triply-heavy pentaquarks QQQnn(Q=b,c)in the unified MIT bag *** construct the color-spin wave functions of the triply-heavy pentaquarks and use the numerical variational method to compute all the ground-state masses of these *** excluding the scattering states in configuration spsce,we computed the decay width ratios of each decay channel relative to the maximum width for the compact pentaquark states,obtaining the main decay modes of the triply-heavy pentaquark systems.

关键词： pentaquark mass decay channels

Gravitational form factors of the proton from near-threshold vector meson photoproduction

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Chinese physics C 2024年第5期48卷 226-234页

作者：王晓云曾凡聪张纪元 Department of physics Lanzhou University of TechnologyLanzhou 730050China lanzhou Center for Theoretical physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of MoELanzhou UniversityLanzhou 730000China institute of High Energy physics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

We systematically analyze the quark and gluon gravitational form factors(GFFs)of the proton by connecting the energy-momentum tensor and near-threshold vector meson photoproduction(NTVMP).Specifically,the quark contributions of GFFs are determined by applying global fitting to the cross section of the lightest vector mesonρ0 *** with the gluon GFFs obtained from heavy quarkonium J/ψphotoproduction data,the complete GFFs are obtained and compared with the experimental results and lattice quantum chromodynamics *** addition,we use the resonance via Padé(RVP)method based on the Schlessinger point method to obtain a model-independent quark D-term distribution through direct analytical continuation of deeply virtual Compton scattering experimental *** errors are considered,the results obtained with RVP are essentially consistent with those obtained by ***,the comprehensive information on GFFs helps to uncover the mass distribution and mechanical properties inside the *** study is not only an important basis for delving into the enigmatic properties of the proton,but also has significance for theoretically guiding future JLab and EIC experimental measurements.

关键词： gravitational form factors properties of the proton vector mesonphotoproduction Schlessinger point method

Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

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Nuclear Science and Techniques 2024年第2期35卷 145-159页

作者： Yan-Yan Ding Yang-Bo Nie Yue Zhang Zhi-Jie Hu Qi Zhao Huan-Yu Zhang Kuo-Zhi Xu Shi-Yu Zhang Xin-Yi Pan Chang-Lin Lan Jie Ren Xi-Chao Ruan Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China institute of Fluid physics China Academy of Engineering PhysicsMianyang 62100China

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China institute of Atomic *** leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight *** samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 *** leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and *** on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were *** results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

关键词： Leakage neutron spectra Uranium D-T neutron source Evaluated nuclear data

Molecular design of recyclable thermosetting polyimide and its composite with excellent mechanical and tribological properties

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Friction 2024年第3期12卷 452-461页

作者： Xiaoyue WANG Zenghui YANG Tingmei WANG Qihua WANG Xinrui ZHANG Song LI Key Laboratory of Science and Technology on Wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Recyclability of thermosetting polymers and their composites is a challenge for alleviating environmental pollution and resource *** this study,solvent-recyclable thermosetting polyimide(PI)and its composite were successfully *** tensile strength,elongation at break,and Young’s modulus of PI are 108.70±7.29 MPa,19.35%±3.89%,and 2336.42±128.00 MPa,*** addition of reduced graphene oxide(RGO)not only enhances the mechanical properties of PI but also endows it with excellent tribological *** PI illustrates a high recycling efficiency of 94.15%,but the recycled composite exhibits inferior mechanical *** recycling and utilization of PI and its composite are realized through imine bonds(-C=N),which provides new guidance for solving the problem of environmental pollution and resource waste and is potential application in the field of sustainable tribology.

关键词： thermosetting polyimide(PI) recyclability dynamic covalent bonds friction and wear polymer composites

Exploration of the coupled lattice Boltzmann model based on a multiphase field model:A study of the solid-liquid-gas interaction mechanism in the solidification process

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Chinese physics B 2024年第3期33卷 638-648页

作者：朱昶胜王利军高梓豪刘硕李广召 College of Computer and Communication Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Gansu Advanced Processing and Recycling of Non-Ferrous Metal Lanzhou University of TechnologyLanzhou 730050China institute of Modern physics Chinese Academy of SciencesLanzhou 730000China

A multiphase field model coupled with a lattice Boltzmann(PF-LBM)model is proposed to simulate the distribution mechanism of bubbles and solutes at the solid-liquid interface,the interaction between dendrites and bubbles,and the effects of different temperatures,anisotropic strengths and tilting angles on the solidified organization of the SCN-0.24wt.%butanedinitrile alloy during the solidification *** model adopts a multiphase field model to simulate the growth of dendrites,calculates the growth motions of dendrites based on the interfacial solute equilibrium;and adopts a lattice Boltzmann model(LBM)based on the Shan-Chen multiphase flow to simulate the growth and motions of bubbles in the liquid phase,which includes the interaction between solid-liquid-gas *** simulation results show that during the directional growth of columnar dendrites,bubbles first precipitate out slowly at the very bottom of the dendrites,and then rise up due to the different solid-liquid densities and pressure *** bubbles will interact with the dendrite in the process of flow migration,such as extrusion,overflow,fusion and *** the case of wide gaps in the dendrite channels,bubbles will fuse to form larger irregular bubbles,and in the case of dense channels,bubbles will deform due to the extrusion of *** the simulated region,as the dendrites converge and diverge,the bubbles precipitate out of the dendrites by compression and diffusion,which also causes physical phenomena such as fusion and spillage of the *** results reveal the physical mechanisms of bubble nucleation,growth and kinematic evolution during solidification and interaction with dendrite growth.

关键词： multiphase field model lattice Boltzmann model(LBM) Shan-Chen multiphase flow solidification organization

Magnetism of NaYbS_(2):From finite temperatures to ground state

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Science China(physics,Mechanics & Astronomy) 2024年第10期67卷 92-104页

作者： Weizhen Zhuo Zheng Zhang Mingtai Xie Anmin Zhang Jianting Ji Feng Jin Qingming Zhang School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China Beijing National Laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Rare-earth chalcogenide compounds ARECh_(2)(A=alkali or monovalent metal,RE=rare earth,Ch=O,S,Se,Te)are a large family of quantum spin liquid(QSL)candidate ***2is a representative member of the *** key issues on NaYbS_(2),particularly how to determine the highly anisotropic spin Hamiltonian and describe the magnetism at finite temperatures and the ground state,remain to be *** this paper,we conducted an in-depth and comprehensive study on the magnetism of NaYbS_(2) from finite temperatures to the ground ***,we successfully detected three crystalline electric field(CEF)excitation energy levels using low-temperature Raman scattering *** them with the CEF theory and magnetization data,we worked out the CEF parameters,CEF energy levels,and CEF *** further determined a characteristic temperature of~40 K,above which the magnetism is dominated by CEF excitations while below which the spinexchange interactions play a main *** characteristic temperature has been confirmed by the temperature-dependent electron spin resonance(ESR)***-temperature ESR experiments on the dilute magnetic doped crystal of NaYb_(0.1)Lu_(0.9)S_(2) further helped us to determine the accurate ***,we quantitatively obtained the spin-exchange interactions in the spin Hamiltonian by consistently simulating the magnetization and specific heat ***,the above studies allow us to explore the ground state magnetism of NaYbS_(2) by using the density matrix renormalization *** combined numerical calculations and experimental results to demonstrate that the ground state of NaYbS_(2) is a Dirac-like QSL.

关键词： rare-earth chalcogenide anisotropic spin Hamiltonian quantum spin liquid