arXiv: Plasma Physics最新文献_第6页

Resonance overlap and nonlinear features of the beam–plasma system 光束-等离子体系统的共振重叠与非线性特性

arXiv: Plasma Physics Pub Date : 2020-08-01 DOI: 10.1017/s0022377820000744

N. Carlevaro, G. Montani, M. Falessi

引用次数: 2

Spatially dependent modeling and simulation of runaway electron mitigation in DIII-D DIII-D中失控电子减缓的空间依赖建模与仿真

arXiv: Plasma Physics Pub Date : 2020-07-31 DOI: 10.1063/5.0022072

M. Beidler, D. del-Castillo-Negrete, L. Baylor, D. Shiraki, D. Spong

{"title":"Spatially dependent modeling and simulation of runaway electron mitigation in DIII-D","authors":"M. Beidler, D. del-Castillo-Negrete, L. Baylor, D. Shiraki, D. Spong","doi":"10.1063/5.0022072","DOIUrl":"https://doi.org/10.1063/5.0022072","url":null,"abstract":"New simulations with the Kinetic Orbit Runaway electron (RE) Code KORC show RE deconfinement losses to the wall are the primary current dissipation mechanism in DIII-D experiments with high-Z impurity injection, and not collisional slowing down. The majority of simulations also exhibit an increase in the RE beam energy due to acceleration by the induced toroidal electric field, even while the RE beam current is decreasing. In this study, KORC integrates RE orbits using the relativistic guiding center equations of motion, and incorporates time-sequenced, experimental reconstructions of the magnetic and electric fields and line integrated electron density to construct spatiotemporal models of electron and partially-ionized impurity transport in the companion plasma. Simulation results indicate current profile changes due to increased pitch angle scattering of REs by injected impurities lower the rotational transform and lead to the deconfinement of REs. Comparisons of experimental current evolution and KORC results demonstrate the importance of including Coulomb collisions with partially-ionized impurity physics, initial RE energy, pitch angle, and spatial distributions, and spatiotemporal electron and partially-ionized impurity transport. This research provides an initial quantification of the efficacy of RE mitigation via injected impurities, and identification of the critical role played by loss of confinement as compared to the relatively slow collisional damping.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76462060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Ultrafast x-ray imaging of pulsed plasmas in water 水中脉冲等离子体的超快x射线成像

arXiv: Plasma Physics Pub Date : 2020-07-29 DOI: 10.1103/PhysRevResearch.3.L022021

Christopher Campbell, Xin Tang, Y. Sechrest, K. Fezzaa, Zhehui Wang, D. Staack

{"title":"Ultrafast x-ray imaging of pulsed plasmas in water","authors":"Christopher Campbell, Xin Tang, Y. Sechrest, K. Fezzaa, Zhehui Wang, D. Staack","doi":"10.1103/PhysRevResearch.3.L022021","DOIUrl":"https://doi.org/10.1103/PhysRevResearch.3.L022021","url":null,"abstract":"Pulsed plasmas in liquids exhibit complex interaction between three phases of matter (liquids, gas, plasmas) and are currently used in a wide range of applications across several fields, however significant knowledge gaps in our understanding of plasma initiation in liquids hinder additional application and control; this area of research currently lacks a comprehensive predictive model. To aid progress in this area experimentally, here we present the first-known ultrafast (50 ps) X-ray images of pulsed plasma initiation processes in water (+25 kV, 10 ns, 5 mJ), courtesy of the X-ray imaging techniques available at Argonne National Laboratory's Advanced Photon Source (APS), with supporting nanosecond optical imaging and a computational X-ray diffraction model. These results clearly resolve narrow (~10 micron) low-density plasma channels during initiation timescales typically obscured by optical emission (<100 ns), a well-known and difficult problem to plasma experiments without access to state-of-the-art X-ray sources such as the APS synchrotron. Images presented in this work speak to several of the prevailing plasma initiation hypotheses, supporting electrostriction and bubble deformation as dominant initiation phenomena. We also demonstrate the plasma setup used in this work as a cheap ($<$US$100k), compact, and repeatable benchmark imaging target (29.1 km/s, 1 TW/cm$^2$) useful for the development of next-generation ultrafast imaging of high-energy-density physics (HEDP), as well as easier integration of HEDP research into synchrotron-enabled facilities.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78949312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Emission of charged particles from laser-induced germanium ecton, vacuum spark, and vacuum arc 激光诱导锗外介子、真空火花和真空电弧的带电粒子发射

arXiv: Plasma Physics Pub Date : 2020-07-22 DOI: 10.1063/5.0012727

V. Porshyn

引用次数: 0

Excitation of dust acoustic shock waves in an inhomogeneous dusty plasma 非均匀尘埃等离子体中尘埃声激波的激发

arXiv: Plasma Physics Pub Date : 2020-07-18 DOI: 10.1063/5.0009397

G. Arora, P. Bandyopadhyay, M. Hariprasad, A. Sen

引用次数: 7

Nonlinear wakefields and electron injection in cluster plasma 非线性尾流场与团簇等离子体中的电子注入

arXiv: Plasma Physics Pub Date : 2020-07-10 DOI: 10.1103/physrevaccelbeams.23.093501

M. Mayr, B. Spiers, R. Aboushelbaya, R. Paddock, J. Sadler, Charles Sillett, Robin H. W. Wang, Karl Krushelnick, P. Norreys

{"title":"Nonlinear wakefields and electron injection in cluster plasma","authors":"M. Mayr, B. Spiers, R. Aboushelbaya, R. Paddock, J. Sadler, Charles Sillett, Robin H. W. Wang, Karl Krushelnick, P. Norreys","doi":"10.1103/physrevaccelbeams.23.093501","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.23.093501","url":null,"abstract":"Laser and beam driven wakefields promise orders of magnitude increases in electric field gradients for particle accelerators for future applications. Key areas to explore include the emittance properties of the generated beams and overcoming the dephasing limit in the plasma. In this paper, the first in-depth study of the self-injection mechanism into wakefield structures from non-homogeneous cluster plasmas is provided using high-resolution two dimensional particle-in-cell simulations. The clusters which are typical structures caused by ejection of gases from a high-pressure gas jet have a diameter much smaller than the laser wavelength. Conclusive evidence is provided for the underlying mechanism that leads to particle trapping, comparing uniform and cluster plasma cases. The accelerated electron beam properties are found to be tunable by changing the cluster parameters. The mechanism explains enhanced beam charge paired with large transverse momentum and energy which has implications for the betatron x-ray flux. Finally, the impact of clusters on the high-power laser propagation behavior is discussed.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80520105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Magnetization around mix jets entering inertial confinement fusion fuel 进入惯性约束聚变燃料的混合射流周围的磁化

arXiv: Plasma Physics Pub Date : 2020-07-08 DOI: 10.1063/5.0012959

J. Sadler, Hui Li, B. Haines

{"title":"Magnetization around mix jets entering inertial confinement fusion fuel","authors":"J. Sadler, Hui Li, B. Haines","doi":"10.1063/5.0012959","DOIUrl":"https://doi.org/10.1063/5.0012959","url":null,"abstract":"Engineering features are known to cause jets of ablator material to enter the fuel hot-spot in inertial confinement fusion implosions. The Biermann battery mechanism wraps them in self-generated magnetic field. We show that higher-Z jets have an additional thermoelectric magnetic source term that is not present for hydrogen jets, verified here through a kinetic simulation. It has similar magnitude to the Biermann term. We then include this in an extended magneto-hydrodynamics approach to post-process an xRAGE radiation-hydrodynamic implosion simulation. The simulation includes an accurate model for the capsule fill tube, producing a dense carbon jet that becomes wrapped in a 4000T magnetic field. A simple spherical carbon mix model shows that this insulates the electron heat conduction enough to cause contraction of the jet to an optically thick equilibrium. The denser magnetized jet hydrodynamics could change its core penetration and therefore the final mix mass, which is known to be well correlated with fusion yield degradation. Fully exploring this will require self-consistent magneto-hydrodynamic simulations. Experimental signatures of this self-magnetization may emerge in the high energy neutron spectrum.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80005645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Blob interactions in 2D scrape-off layer simulations 二维刮擦层模拟中的斑点相互作用

arXiv: Plasma Physics Pub Date : 2020-07-08 DOI: 10.1063/5.0021314

G. Decristoforo, F. Militello, T. Nicholas, J. Omotani, C. Marsden, N. Walkden, O. E. Garcia

{"title":"Blob interactions in 2D scrape-off layer simulations","authors":"G. Decristoforo, F. Militello, T. Nicholas, J. Omotani, C. Marsden, N. Walkden, O. E. Garcia","doi":"10.1063/5.0021314","DOIUrl":"https://doi.org/10.1063/5.0021314","url":null,"abstract":"Interaction of coherent structures known as blobs in the scrape-off layer of magnetic confinement fusion devices is investigated. Isolated and interacting seeded blobs as well as full plasma turbulence are studied with a two dimensional fluid code. The features of the blobs (size, amplitude, position) are determined with a blob tracking algorithm, which identifies them as coherent structures above a chosen density threshold and compared to a conventional center of mass approach. The agreement of these two methods is shown to be affected by the parameters of the blob tracking algorithm. The benchmarked approach is then extended to a population of interacting plasma blobs with statistically distributed amplitudes, sizes and initial positions for different levels of intermittency. As expected, for decreasing intermittency, we observe an increasing number of blobs deviating from size-velocity scaling laws of perfectly isolated blobs. This is found to be caused by the interaction of blobs with the electrostatic potential of one another, leading to higher average blob velocities. The degree of variation from the picture of perfectly isolated blobs is quantified as a function of the average waiting time of the seeded blobs.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78738297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Shocks propagate in a 2D dusty plasma with less attenuation than due to gas friction alone 冲击在二维尘埃等离子体中传播，其衰减比单独由气体摩擦引起的衰减要小

arXiv: Plasma Physics Pub Date : 2020-07-04 DOI: 10.1063/5.0016504

A. Kananovich, John Goree

引用次数: 9

Optical shaping of plasma cavity for controlled laser wakefield acceleration 控制激光尾场加速的等离子体腔光学整形

arXiv: Plasma Physics Pub Date : 2020-07-02 DOI: 10.1103/PHYSREVRESEARCH.2.043319

Bobbili Sanyasi Rao, M. Cho, H. T. Kim, J. Shin, K. Oh, J. Jeon, Byung Ju Yoo, S. Cho, J. W. Yoon, J. Sung, S. Lee, C. Nam

引用次数: 2