Physics of Plasmas最新文献_第9页

Characterizing the effects of drive asymmetries, component offsets, and joint gaps in double shell capsule implosions 确定双壳囊内爆中驱动不对称、组件偏移和连接间隙的影响特征

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-09 DOI: 10.1063/5.0195454

S. Goodarzi, I. Sagert, J. P. Sauppe, P. A. Keiter, E. N. Loomis, R. F. Sacks, Z. L. Mohamed, S. Palaniyappan, E. C. Merritt, B. M. Haines, B. M. Patterson, D. D. Meyerhofer, D. S. Montgomery, D. W. Schmidt

{"title":"Characterizing the effects of drive asymmetries, component offsets, and joint gaps in double shell capsule implosions","authors":"S. Goodarzi, I. Sagert, J. P. Sauppe, P. A. Keiter, E. N. Loomis, R. F. Sacks, Z. L. Mohamed, S. Palaniyappan, E. C. Merritt, B. M. Haines, B. M. Patterson, D. D. Meyerhofer, D. S. Montgomery, D. W. Schmidt","doi":"10.1063/5.0195454","DOIUrl":"https://doi.org/10.1063/5.0195454","url":null,"abstract":"This work provides a numerical study of how double shell capsule deformations caused by drive asymmetries and fabrication imperfections affect implosion symmetry and neutron yield. Hydrodynamics simulations are performed in two dimensions and focus on low-mode deformations that are caused by corresponding asymmetries in the Hohlraum drive, component offsets, and ablator joint gaps. By providing a parameter study of these features, our goal is to understand the dominant sources for inner shell deformation and yield degradation. The discussed capsules are composed of an aluminum ablator with a chromium inner shell. The latter encloses a carbon-deuterium foam ball that serves as fuel. We find that for clean capsules, even-numbered low-mode asymmetries in the drive are imprinted on the ablator and smoothly transferred to the inner shell during shell collision. The resulting deformation of the inner shell is more pronounced with larger fuel radius, while the yield is inversely proportional to the amplitude of the drive asymmetry and varies by factors ≤4 in comparison with clean simulations. Capsule component offsets in the vertical direction and ablator thickness nonuniformity result in p1-type deformations of the imploding inner shell. Finally, joint gaps have the largest effect in deforming the ablator and inner shell and degrading yield. While small gap widths (1 μm) result in prolate inner shells, larger gap widths (4 μm) cause an oblate deformation. More importantly, capsules with a small outer gap (1 μm) experience a dramatic drop in yield, typically &lt;3% of a clean simulation.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"23 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inverse aspect-ratio expanded tokamak equilibria 反长宽比膨胀托卡马克平衡态

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-09 DOI: 10.1063/5.0215345

R. Fitzpatrick

引用次数: 0

Weakly nonlinear incompressible Rayleigh–Taylor–Kelvin–Helmholtz instability in plane geometry 平面几何中的弱非线性不可压缩瑞利-泰勒-开尔文-赫尔姆霍兹不稳定性

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-09 DOI: 10.1063/5.0216178

Zhen-Qi Zou, Jun-Feng Wu, Guo-Wei Yang, Li-Feng Wang, Wei-Yan Zhang

{"title":"Weakly nonlinear incompressible Rayleigh–Taylor–Kelvin–Helmholtz instability in plane geometry","authors":"Zhen-Qi Zou, Jun-Feng Wu, Guo-Wei Yang, Li-Feng Wang, Wei-Yan Zhang","doi":"10.1063/5.0216178","DOIUrl":"https://doi.org/10.1063/5.0216178","url":null,"abstract":"A weakly nonlinear theoretical model is established for the two-dimensional incompressible Rayleigh–Taylor–Kelvin–Helmholtz instability (RT–KHI). The evolution of the perturbation interface is analytically studied by the third-order solution of the planar RT–KHI induced by a single-mode surface perturbation. The difference between the weakly nonlinear growth for Rayleigh–Taylor instability (RTI), Kelvin–Helmholtz instability (KHI), and RT–KHI in plane geometry is discussed. The trend of bubble and spike amplitudes with the Atwood number and the Richardson number is discussed in detail. The bubble and spike amplitudes of RT–KHI change from the KHI case to the RTI case as the Richardson number increases. The deflecting distance of bubble and spike vertices becomes smaller compared to the KHI case as the Richardson number increases. The dependence of the nonlinear saturation amplitude of RT–KHI on the Atwood number, the Richardson number, and the initial perturbation is obtained. The Richardson number is as vital to the nonlinear saturation amplitude as the Atwood number. It is found that the variation of the nonlinear saturation amplitude with the Atwood number at different Richardson numbers is divided into three parts, namely, “RTI-like part,” “transition part,” and “KHI-like part.” In the transition part, the trend of the nonlinear saturation amplitude increasing with the Atwood number is completely opposite to the RTI and KHI cases. Finally, the theory is compared to the numerical simulation under identical initial conditions and displays good correspondence in the linear and weakly nonlinear stages.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"87 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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PW laser intensity enhancement by a hollow solid plasma cone 空心固体等离子锥增强 PW 激光强度

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-09 DOI: 10.1063/5.0219701

Xiaolong Zheng, Xiaomei Zhang, Baifei Shen

引用次数: 0

Regarding the extension of metaplectic geometrical optics to modeling evanescent waves in ray-tracing codes 关于将元折射几何光学扩展到射线追踪代码中的蒸发波建模

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-09 DOI: 10.1063/5.0221784

N. A. Lopez, R. Højlund, M. G. Senstius

{"title":"Regarding the extension of metaplectic geometrical optics to modeling evanescent waves in ray-tracing codes","authors":"N. A. Lopez, R. Højlund, M. G. Senstius","doi":"10.1063/5.0221784","DOIUrl":"https://doi.org/10.1063/5.0221784","url":null,"abstract":"Metaplectic geometrical optics (MGO) is a recently developed ray-tracing framework to accurately compute the wavefield behavior near a caustic (turning point or focal point), where traditional ray-tracing breaks down. However, MGO has thus far been restricted to having real-valued wavevectors. This is disadvantageous because often upon crossing a caustic from the “illuminated” region to the “shadow” region, two real-valued rays coalesce into one complex-valued ray corresponding to the transition from propagating to evanescent behavior. One can distinguish caustics as having either “illuminated shadows” or “proper shadows”—the former corresponds to when the shadow still contains real-valued rays (albeit in a fewer quantity than in the illuminated region), while the latter corresponds to when the shadow contains no real-valued rays. Here, by means of examples, we show how MGO can be used to model both types of shadows. First, for illuminated shadows, we show that MGO can actually be used “as is,” provided a corrected integration scheme is used compared to that proposed in the original references. This is then implemented and demonstrated in a recently developed MGO ray-tracing code. Second, we show that for proper shadows, the MGO formalism can still be used if the symplectic rotation matrix that removes caustics along rays is allowed to be complex-valued. In both cases, strong agreement is seen between the MGO and the exact solution, demonstrating the potential of MGO for improving the predictive capability of ray-tracing codes and laying the foundations for modeling more complicated evanescent phenomena such as tunneling with MGO.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"35 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comment on “ENN's roadmap for proton-boron fusion based on spherical torus” [Phys. Plasmas 31, 062507 (2024)] 关于 "基于球形环的 ENN 质子-硼核聚变路线图 "的评论 [Phys. Plasmas 31, 062507 (2024)]

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-05 DOI: 10.1063/5.0223575

Zhi Li

引用次数: 0

Influence of O2 content on surface modification of epoxy resin using He/CF4 atmospheric pressure plasma jet to improve surface flashover strength 氧气含量对使用 He/CF4 常压等离子体射流改性环氧树脂表面以提高表面闪蒸强度的影响

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-05 DOI: 10.1063/5.0218575

Lijun Wang, Huan Zhao, Jie Liu, Yile Wang

{"title":"Influence of O2 content on surface modification of epoxy resin using He/CF4 atmospheric pressure plasma jet to improve surface flashover strength","authors":"Lijun Wang, Huan Zhao, Jie Liu, Yile Wang","doi":"10.1063/5.0218575","DOIUrl":"https://doi.org/10.1063/5.0218575","url":null,"abstract":"In order to improve the surface flashover strength of the insulation materials and solve the problem that the relatively high price of CF4 restricts the large-scale application of fluorination modification of CF4 atmospheric pressure plasma jet (APPJ) in the industrial field, He/CF4/O2 APPJ with different O2 content is used to treat epoxy resin (EP) dielectric material. By analyzing the results of scanning electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy, the influence of O2 content on the multiple characteristics of EP surface before and after APPJ treatment is studied. Flashover experiment is also carried out on EP surface before and after APPJ treatment. It is found that the addition of 0.1% O2 can increase the mature voltage of the EP surface by about 16.10% compared with untreated EP surface. It is concluded that the improvement of the surface flashover strength with a small amount of O2 (within 0.1%) is influenced by the surface roughness and chemical composition of the dielectric. The deposition effect of APPJ on EP surface is enhanced to increase the surface roughness and reaches the best at 0.1% O2, because the addition of excessive O2 will weaken the APPJ intensity. It is speculated that the creepage distance of the EP surface is increased to inhibit the formation of electron collapse and the content of electronegative fluorine and oxygen on the EP surface is increased under a small amount of O2 addition, resulting in the inhibition of the formation of surface flashover.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"28 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Different kinds of accelerated propagation of relativistic electromagnetic plasma wavepackets 相对论电磁等离子体波包的不同加速传播方式

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-05 DOI: 10.1063/5.0220386

Felipe A. Asenjo

引用次数: 0

Investigation of self-focusing of Gaussian laser beams within magnetized plasma via source-dependent expansion method 通过随源扩展法研究磁化等离子体内高斯激光束的自聚焦情况

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-05 DOI: 10.1063/5.0211393

A. A. Molavi Choobini, S. S. Ghaffari-Oskooei

引用次数: 0

MHD stability trends and improved performance of LHD inward-shifted configurations: The role of the neutral beam current drive and thermal plasma density MHD 稳定趋势和 LHD 内移配置的改进性能：中性束流驱动和热等离子体密度的作用

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-05 DOI: 10.1063/5.0206400

J. Varela, K. Nagaoka, Y. Takemura, K. Y. Watanabe, K. Ida, M. Yoshinuma, K. Nagasaki, A. Cappa, S. Sharapov, D. A. Spong, L. Garcia, Y. Ghai, J. Ortiz

{"title":"MHD stability trends and improved performance of LHD inward-shifted configurations: The role of the neutral beam current drive and thermal plasma density","authors":"J. Varela, K. Nagaoka, Y. Takemura, K. Y. Watanabe, K. Ida, M. Yoshinuma, K. Nagasaki, A. Cappa, S. Sharapov, D. A. Spong, L. Garcia, Y. Ghai, J. Ortiz","doi":"10.1063/5.0206400","DOIUrl":"https://doi.org/10.1063/5.0206400","url":null,"abstract":"The aim of the present study is to analyze the effect of the neutral beam current drive (NBCD), thermal plasma density, and NBI operational regime on the stability of pressure gradient-driven modes (PGDM) and Alfvén eigenmodes (AE) in LHD inward-shifted configurations. The stabilization of n/m=1/2 PGDM (n toroidal mode and m poloidal mode) is observed in the discharge 167 800 during the co-NBCD phase. The iota profile evolution measured by motional stark effect diagnostic may indicate the iota profile up-shift caused by the co-NBCD can induce a non-resonant transition of the rational surface 1/2 before the mode stabilization. The evolution of the iota profile and continuum gaps in the discharge 167 805 during the ctr-NBCD phase leads to the stabilization of the AE, caused by the narrowing of the continuum gap as the iota profile down-shift. Opposite stability trends are identified for PGDM and AE stability with respect to the thermal plasma density. A larger thermal plasma density (larger thermal β) further enhances PGDM although the continuum gaps are narrower leading to configurations with stable AEs. The linear stability of AEs is analyzed using the gyro-fluid FAR3d code to reproduce the AE stability trends observed in the experiments with respect to the NBCD and thermal plasma density. The analysis of hypothetical scenarios dedicated to study different NBI operational regimes with respect to EP energy, and β and radial density profiles indicate off-axis NBI operation shows a higher EP β threshold to destabilize AEs compared to on-axis configuration. This is explained by the presence of a TAE gap in the inner plasma region, easily destabilized by an on-axis NBI injection. The control of the NBCD and thermal plasma in the discharge 167 800 shows a transitory stabilization of PGDM and AEs, as well as an improved discharge performance identified by an increment of the neutron fluxes.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"14 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0