Physics of Plasmas最新文献_第9页

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

Diagnosing hot-spot symmetry in surrogate ignition experiments via secondary DT-neutron spectroscopy at the NIF 通过 NIF 的二次 DT 中子光谱诊断代理点火实验中的热点对称性

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-02 DOI: 10.1063/5.0210125

P. J. Adrian, R. Bionta, D. Casey, M. Gatu Johnson, S. Kerr, B. Lahmann, C. K. Li, R. Nora, R. D. Petrasso, G. Rigon, D. Schlossberg, F. H. Séguin, J. A. Frenje

{"title":"Diagnosing hot-spot symmetry in surrogate ignition experiments via secondary DT-neutron spectroscopy at the NIF","authors":"P. J. Adrian, R. Bionta, D. Casey, M. Gatu Johnson, S. Kerr, B. Lahmann, C. K. Li, R. Nora, R. D. Petrasso, G. Rigon, D. Schlossberg, F. H. Séguin, J. A. Frenje","doi":"10.1063/5.0210125","DOIUrl":"https://doi.org/10.1063/5.0210125","url":null,"abstract":"The directional energy spectrum of neutrons generated from the in-flight fusion reaction of 1-MeV tritons contains information about the hot-spot symmetry. The National Ignition Facility (NIF) fields Symmetry Capsule (Symcap) implosions, which have historically measured the symmetry of the radiation, drive by measuring the hot-spot shape via x-ray self-emission. Symcaps are used to tune the hot-spot symmetry for ignition experiments at the NIF. This work shows the relationship between directional secondary DT-n spectra and x-ray imaging data for a large database of Symcap implosions. A correlation is observed between the relative widths of the DT-n spectra measured with nTOFs and the shape measured with x-ray imaging. A Monte Carlo model, which computes the directional secondary DT-n spectrum, is used to interpret the results. A comparison of the x-ray and secondary DT-n data with the Monte Carlo model indicates that 56% of the variance between the two datasets is explained by a P2 asymmetry. More advanced simulations using HYDRA suggest that the unaccounted variance is due to P1 and P4 asymmetries present in the hot spot. The comparison of secondary DT-n data and x-ray imaging data to the modeling shows the DT-n data contain important information that supplements current P2 measurements and contain new information about the P1 asymmetry.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"84 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883802","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

SPLEND1D, a reduced one-dimensional model to investigate the physics of plasma detachment SPLEND1D - 用于研究等离子体脱离物理学的简化一维模型

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-02 DOI: 10.1063/5.0202986

O. Février, S. Gorno, C. Theiler, M. Carpita, G. Durr-Legoupil-Nicoud, M. von Allmen

{"title":"SPLEND1D, a reduced one-dimensional model to investigate the physics of plasma detachment","authors":"O. Février, S. Gorno, C. Theiler, M. Carpita, G. Durr-Legoupil-Nicoud, M. von Allmen","doi":"10.1063/5.0202986","DOIUrl":"https://doi.org/10.1063/5.0202986","url":null,"abstract":"Studying the process of divertor detachment and the associated complex interplay of plasma dynamics and atomic physics processes is of utmost importance for future fusion reactors. While simplified analytical models exist to interpret the general features of detachment, they are limited in their predictive power, and complex two-dimensional (2D) or even three-dimensional (3D) codes are generally required to provide a self-consistent picture of the divertor. As an intermediate step, one-dimensional (1D) models of the scrape-off layer (SOL) can be particularly insightful as the dynamics are greatly simplified, while still self-consistently including various source and sink terms at play, as well as additional important effects such as flows. These codes can be used to shed light on the physics at play, to perform fast parameter scans, or to interpret experiments. In this paper, we introduce the SPLEND1D (Simulator of PLasma ENabling Detachment in 1D) code: a fast and versatile 1D SOL model. We present in detail the model that is implemented in SPLEND1D. We then employ the code to explore various elements of detachment physics for parameters typical of the Tokamak à Configuration Variable, including the atomic physics and other processes behind power and momentum losses, and explore the various hypotheses and free parameters of the model.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"217 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883801","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

Analysis of communication characteristics of Airy vortex beams in turbulent plasma sheath 湍流等离子鞘中空气涡旋束的通信特性分析

IF 2.2 3区物理与天体物理

Physics of Plasmas Pub Date : 2024-08-02 DOI: 10.1063/5.0194716

Tingwei Sun, Qingqing Deng, Wei Chen, Yong Bo, Lixia Yang, Lixin Guo

{"title":"Analysis of communication characteristics of Airy vortex beams in turbulent plasma sheath","authors":"Tingwei Sun, Qingqing Deng, Wei Chen, Yong Bo, Lixia Yang, Lixin Guo","doi":"10.1063/5.0194716","DOIUrl":"https://doi.org/10.1063/5.0194716","url":null,"abstract":"In this paper, a transmission model of power-exponential Airy vortex beams in plasma turbulence is established based on the random phase screen theory, and the information transmission characteristics of Airy vortex beams are compared under the OOK, BPSK, and DPSK modulation modes in free-space optical communication systems. Bit error rates (BERs) were calculated for different power indices (n), undulation variances (&lt;Δn2&gt;), transmission distances, and anisotropy parameters. In addition, the orbital angular momentum multiplexing of Airy vortex beams in the Line-of-Sight multiple input multiple output system under a plasma turbulence environment is investigated. The spectral efficiency (SE) is analyzed for different signal-to-noise ratio (SNR) and radii of the emitting surface, and the effects of the variation in the system's numerical aperture and the power exponent on the SE and the effective degrees of freedom in space are analyzed. The results show that the Airy beam has better turbulence resistance than the Laguerre–Gaussian beam. The power-exponential Airy beam has better transmission performance than the conventional Airy beam. By increasing the anisotropy parameter, the BER of the system decreases. When the &lt;Δn2&gt; and the transmission distance increase, the BER increases. Increasing the SNR, the radius of the launching surface and the choice of power-exponential Airy beams can improve the channel capacity. These findings provide a theoretical basis for the problem of optical signal propagation in plasma turbulence.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"190 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883803","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