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Plasma Science and Technology 2024年第5期26卷 47-55页

作者：李宜霖廖晖周海洋孙玄 Department of Plasma Physics and fusion Engineering School of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026People’s Republic of China

Field reversed configuration(FRC)is widely considered as an ideal target plasma for magnetoinertial ***,its confinement and stability,both proportional to the radius,will deteriorate inevitably during radial ***,we propose a new fusion approach based on axial compression of a large-sized *** axial compression can be made by plasma jets or plasmoids converging onto the axial ends of the *** parameter space that can reach the ignition condition while preserving the FRC's overall quality is studied using a numerical model based on different FRC confinement *** is found that ignition is possible for a large FRC that can be achieved with the current FRC formation techniques if compression ratio is greater than 50.A more realistic compression is to combine axial with moderate radial compression,which is also presented and calculated in this work.

关键词： field reversed configuration magnetized target fusion axial compression

Nonlinear dynamics of the reversed shear Alfvén eigenmode in burning plasmas

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Plasma Science and Technology 2024年第5期26卷 1-16页

作者：王涛魏士朝 Sergio BRIGUGLIO Gregorio VLAD Fulvio ZONCA 仇志勇 Institute for fusion Theory and Simulation and School of Physics Zhejiang UniversityHangzhou 310027People’s Republic of China Center for Nonlinear Plasma Science ENEA C.R.FrascatiFrascati 00044Italy fusion and nuclear Safety Department ENEA C.R.FrascatiFrascati 00044Italy

In a tokamak fusion reactor operated at steady state,the equilibrium magnetic field is likely to have reversed shear in the core region,as the noninductive bootstrap current profile generally peaks *** reversed shear Alfvén eigenmode(RSAE)as a unique branch of the shear Alfvén wave in this equilibrium,can exist with a broad spectrum in wavenumber and frequency,and be resonantly driven unstable by energetic particles(EP).After briefly discussing the RSAE linear properties in burning plasma condition,we review several key topics of the nonlinear dynamics for the RSAE through both wave-EP resonance and wave-wave coupling channels,and illustrate their potentially important role in reactor-scale fusion *** means of simplified hybrid MHD-kinetic simulations,the RSAEs are shown to have typically broad phase space resonance structure with both circulating and trapped EP,as results of weak/vanishing magnetic shear and relatively low *** the route of wave-EP nonlinearity,the dominant saturation mechanism is mainly due to the transported resonant EP radially decoupling with the localized RSAE mode structure,and the resultant EP transport generally has a convective *** saturated RSAEs also undergo various nonlinear couplings with other collective *** typical routes as parametric decay and modulational instability are studied using nonlinear gyrokinetic theory,and applied to the scenario of spontaneous excitation by a finite amplitude pump *** RSAEs could naturally couple and induce the spectral energy cascade into a low frequency Alfvénic mode,which may effectively transfer the EP energy to fuel ions via collisionless Landau ***,zero frequency zonal field structure could be spontaneously excited by modulation of the pump RSAE envelope,and may also lead to saturation of the pump RSAE by both scattering into stable domain and local distortion of the continuum structure.

关键词： reversed shear Alfvén eigenmode energetic particle nonlinear gyrokinetic theory saturation burning plasma

Measurement of 2p-3d absorption in a hot molybdenum plasma

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Matter and Radiation at Extremes 2024年第4期9卷 68-79页

作者： Gang Xiong Bo Qing Zhiyu Zhang Longfei Jing Yang Zhao Minxi Wei Yimeng Yang Lifei Hou Chengwu Huang Tuo Zhu Tianming Song Min Lv Yan Zhao Yuxue Zhang Guohong Yang Zeqing Wu Jun Yan Yaming Zou Jiyan Zhang Jiamin Yang Shanghai EBIT Laboratory and Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE)Institute of ModernPhysicsFudan UniversityShanghai 200433China Laser fusion Research Center China Academy of Engineering PhysicsMianyang 621900China Institute of Applied Physics and Computational Mathematics Beijing 100088China

We present measurements of the 2p-3d transition opacity of a hot molybdenum-scandium sample with nearly half-vacant molybdenum M-shell configurations.A plastic-tamped molybdenum-scandium foil sample is radiatively heated to high temperature in a compact D-shaped gold Hohlraum driven by∼30 kJ laser energy at the SG-100 kJ laser facility.X rays transmitted through the molybdenum and scandium plasmas are diffracted by crystals and finally recorded by image *** electron temperatures in the sample in particular spatial and temporal zones are determined by the K-shell absorption of the scandium plasma.A combination of the IRAD3D view factor code and the MULTI hydrodynamic code is used to simulate the spatial distribution and temporal behavior of the sample temperature and *** inferred temperature in the molybdenum plasma reaches a average of 138±11 eV.A detailed configuration-accounting calculation of the n=2–3 transition absorption of the molybdenum plasma is compared with experimental measurements and quite good agreement is *** present measurements provide an opportunity to test opacity models for complicated M-shell configurations.

关键词： molybdenum absorption configuration

Spark plasma sintering of tungsten-based WTaVCr refractory high entropy alloys for nuclear fusion applications

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 146-154页

作者： Yongchul Yoo Xiang Zhang Fei Wang Xin Chen Xing-Zhong Li Michael Nastasi Bai Cui Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE 68588USA Nebraska Center for Materials and Nanoscience University of Nebraska-LincolnLincolnNE 68588USA Department of nuclear Engineering Texas A&M UniversityCollege StationTX 77843USA

W-based WTaVCr refractory high entropy alloys (RHEA) may be novel and promising candidate materials for plasma facing components in the first wall and diverter in fusion reactors. This alloy has been developed by a powder metallurgy process combining mechanical alloying and spark plasma sintering (SPS). The SPSed samples contained two phases, in which the matrix is RHEA with a body-centered cubic structure, while the oxide phase was most likely Ta2VO6through a combined analysis of X-ray diffraction (XRD),energy-dispersive spectroscopy (EDS), and selected area electron diffraction (SAED). The higher oxygen affinity of Ta and V may explain the preferential formation of their oxide phases based on thermodynamic calculations. Electron backscatter diffraction (EBSD) revealed an average grain size of 6.2μm. WTaVCr RHEA showed a peak compressive strength of 2997 MPa at room temperature and much higher micro-and nano-hardness than W and other W-based RHEAs in the literature. Their high Rockwell hardness can be retained to at least 1000°C.

关键词： refractory high entropy alloy plasma-facing material fusion reactor spark plasma sintering

3D electromagnetic modelling for high-temperature superconducting dynamo flux pumps using T-A formulation

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High Voltage 2024年第2期9卷 367-379页

作者： Luning Hao Fangliang Dong Jintao Hu Qi Wang Haigening Wei Ismail Patel Adil Shah Yuyang Wu Tim Coombs Department of Engineering University of CambridgeCambridgeUK Plasma Science and fusion Center Massachusetts Institute of TechnologyCambridgeMassachusettsUSA

A high-temperature superconducting(HTS)dynamo flux pump can inject DC currents into closed-loop HTS magnets without *** enables the realisation of current-lead-free or even through-wall charging systems for high-field applications such as nuclear magnetic resonance/magnetic resonance imaging(MRI)magnets,fusion reactors and *** have proposed many simulation models to understand the working principle of HTS dynamos,few of which are in 3D because of converging ***,the influences of many key 3D parameters in the HTS dynamo are scarcely *** authors propose an efficient 3D modelling method of the HTS dynamo based on the T-A *** rotating magnets are modelled by a ring-shaped permanent magnet with space-time-variant remanent flux density to avoid moving ***,together with the T-A formulation,makes the 3D model efficient and *** accuracy of the model is verified by the experimental instantaneous and time-integrated dynamic *** this model,the authors present systematic case studies to thoroughly explore the influences of the key parameters of a dynamo flux pump on the dynamic voltage and *** proposed modelling method and results could significantly benefit the design and optimisation of HTS dynamos for high-field magnets.

关键词： formulation magnets pump

Experimental Investigations of Quasi-Coherent Micro-Instabilities in J-TEXT Ohmic Plasmas

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Chinese Physics Letters 2024年第5期41卷 47-52页

作者：石鹏庄革程芝峰高丽周乙楠刘永罗景庭李景春 Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China International Joint Research Laboratory of Magnetic Confinement fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China Department of Engineering and Applied Physics School of Physical Sciences University of Science and Technology of ChinaHefei 230026China Shenzhen Key Laboratory of nuclear and Radiation Safety Institute for Advanced Study in Nuclear Energy&SafetyCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 510640China

Quasi-coherent micro-instabilities is one of the key topics of magnetic confinement fusion. This work focuses on the quasi-coherent spectra of ion temperature gradient(ITG) and trapped-electron-mode instabilities using newly developed far-forward collective scattering measurements within ohmic plasmas in the J-TEXT *** ITG mode is characterized by frequencies ranging from 30 to 100 k Hz and wavenumbers(k_(θρs)) less than 0.3. Beyond a critical plasma density threshold, the ITG mode undergoes a bifurcation, which is marked by a reduction in frequency and an enhancement in amplitude. Concurrently, enhancements in ion energy loss and degradation in confinement are observed. This ground-breaking discovery represents the first instance of direct experimental evidence that establishes a clear link between ITG instability and ion thermal transport.

关键词： ITG mode collective

On-chip ultrafast stackable dielectric laser positron accelerator

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Chinese Physics B 2024年第3期33卷 350-354页

作者：孙斌何阳帆潘晨浩樊思劼王度王少义赵宗清 Department of Plasma Physics and fusion Engineering School of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026China National Key Laboratory of Plasma Physics Research Center of Laser FusionChina Academy of Engineering PhysicsMianyang 621900China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China State Key Laboratory of High Field Laser Physics and Chinese Academy of Sciences Center for Excellence in Ultra-Intense Laser Science Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Department of Engineering Physics Tsinghua UniversityBeijing 100084China The Institute of Technological Sciences Wuhan UniversityWuhan 430072China

We present a first on-chip positron accelerator based on dielectric laser *** innovative approach significantly reduces the physical dimensions of the positron acceleration apparatus,enhancing its feasibility for diverse *** utilizing a stacked acceleration structure and far-infrared laser technology,we are able to achieve a seven-stage acceleration structure that surpasses the distance and energy gain of using the previous dielectric laser acceleration ***,we are able to compress the positron beam to an ultrafast sub-femtosecond scale during the acceleration process,compared with the traditional methods,the positron beam is compressed to a greater *** also demonstrate the robustness of the stacked acceleration structure through the successful acceleration of the positron beam.

关键词： dielectric laser accelerator positron accelerator high gradient accelerator inverse Cherenkov effect

Effects of counter-current driven by electron cyclotron waves on neoclassical tearing mode suppression

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Chinese Physics B 2024年第5期33卷 501-509页

作者：高钦郑平卫 School of Resource Environment and Safety Engineering University of South ChinaHengyang 421001China Demonstration Base for International Science and Technology Cooperation on nuclear Energy and nuclear Safety University of South ChinaHengyang 421001China

Through theoretical analysis,we construct a physical model that includes the influence of counter-external driven current opposite to the plasma current direction in the neoclassical tearing mode(NTM).The equation is used with this model to obtain the modified Rutherford equation with co-current and counter-current *** with the reported experimental results,numerical simulations have shown that the localized counter external current can only partially suppress NTM when it is far from the resonant magnetic *** some circumstances,the Ohkawa mechanism dominated current drive(OKCD)by electron cyclotron waves can concurrently create both co-current and *** this instance,the minimal electron cyclotron wave power that suppresses a particular NTM was calculated by the Rutherford *** result is marginally less than when taking co-current alone into *** a result,to suppress NTM using OKCD,one only needs to align the co-current with a greater OKCD peak well with the resonant magnetic *** effect of its lower counter-current does not need to be considered because the location of the counter-current deviates greatly from the resonant magnetic surface.

关键词： driven current neoclassical tearing mode modified Rutherford equation electron cyclotron waves

Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： Xian-Lin Yang Chang-Lin Lan Yu-Ting Wei Yi Zhang Gong Jiang Bo Xie Yu Liu Hong-Tao Shen Xiao-Jun Sun School of nuclear Science and Technology Lanzhou UniversityLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi Key Laboratory of nuclear Physics and nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

Systematic study of cluster radioactivity in trans-lead nuclei with various versions of proximity potential formalisms

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Chinese Physics C 2024年第5期48卷 209-225页

作者：刘潇蒋杰栋吴喜军李小华 School of nuclear Science and Technology University of South ChinaHengyang 421001China School of Math and Physics University of South ChinaHengyang 421001China National Exemplary Base for International Sci&Tech.Collaboration of nuclear Energy and nuclear Safety University of South ChinaHengyang 421001China Cooperative Innovation Center for nuclear Fuel Cycle Technology&Equipment University of South ChinaHengyang 421001China Key Laboratory of Low Dimensional Quantum Structures and Quantum Control Hunan Normal UniversityChangsha 410081China

In this study,based on the framework of the Coulomb and proximity potential model(CPPM),we systematically investigate the cluster radioactivity half-lives of 26 trans-lead nuclei by considering the cluster preformation probability,which possesses a simple mass dependence on the emitted cluster according to *** and ***[***.61,1930(1988)].Moreover,we investigate 28 different versions of the proximity potential formalisms,which are the most complete known proximity potential formalisms proposed to describe proton radioactivity,two-proton radioactivity,αdecay,heavy-ion radioactivity,quasi-elastic scattering,fusion reactions,and other *** calculated results show that the modified forms of proximity potential 1977,denoted as Prox.77-12,and proximity potential 1981,denoted as Prox.81,are the most appropriate proximity potential formalisms for the study of cluster radioactivity,as the root-mean-square deviation between experimental data and relevant theoretical results obtained is the least;both values are *** comparison,the universal decay law(UDL)proposed by Qi et al.[***.C 80,044326(2009)],unified formula of half-lives forαdecay and cluster radioactivity proposed by Ni et al.[***.C 78,044310(2008)],and scaling law(SL)in cluster radioactivity proposed by Horoi et al.[***.G 30,945(2004)]are also *** addition,utilizing CPPM with Prox.77-12,Prox.77-1,Prox.77-2,and Prox.81,we predict the half-lives of 51 potential cluster radioactive candidates whose cluster radioactivity is energetically allowed or observed but not yet quantified in *** predicted results are in the same order of magnitude as those obtained using the compared semi-empirical and/or empirical *** the same time,the competition betweenαdecay and cluster radioactivity of these predicted nuclei is *** comparing the half-lives,this study reveals thatαdecay predominates.

关键词： cluster radioactivity half-lives Coulomb and proximity potential model