Journal of Plasma Physics最新文献_第6页

Trivelpiece–Gould modes and low-frequency electron–ion instability of non-neutral plasma 非中性等离子体的 Trivelpiece-Gould 模式和低频电子-离子不稳定性

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-15 DOI: 10.1017/s002237782300137x

Yuriy N. Yeliseyev

{"title":"Trivelpiece–Gould modes and low-frequency electron–ion instability of non-neutral plasma","authors":"Yuriy N. Yeliseyev","doi":"10.1017/s002237782300137x","DOIUrl":"https://doi.org/10.1017/s002237782300137x","url":null,"abstract":"The frequency spectra of the Trivelpiece–Gould modes of a waveguide partially filled with non-neutral plasma are determined numerically by solving the dispersion equation. The modes having azimuthal number $m = 1$ are considered. The results are presented for the entire acceptable range of electron densities, magnetic field strengths, for different values of the charge neutralization coefficient. The Cherenkov resonance condition of an ion with a diocotron mode having a finite value of the longitudinal wave vector was studied. The characteristics of resonant low-frequency electron–ion instability caused by relative azimuth motion of electrons and ions in crossed fields and by the anisotropy of the distribution function of ions are discussed. Ions are created by ionization of residual gas in the plasma volume. Due to the anisotropy, instability occurs not only in the vicinity of the resonance, but also outside it. For typical values of plasma parameters in experiments, estimations of the frequency growth rate are given. A conclusion is drawn that this instability can be the cause of the low-frequency oscillations observed in linear devices with non-neutral plasma produced in an electron beam channel.","PeriodicalId":16846,"journal":{"name":"Journal of Plasma Physics","volume":"7 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761027","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

Nonlinear Hall effect in the stationary a cylinder with a radial heat flux 静止圆柱体中的非线性霍尔效应与径向热通量

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-15 DOI: 10.1017/s0022377824000102

G.S. Bisnovatyi-Kogan, M.V. Glushikhina

引用次数: 0

Calibrated heating rate measurements using electric-field-induced electron extraction in ultracold neutral plasmas 利用超冷中性等离子体中的电场诱导电子萃取测量校准加热速率

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-15 DOI: 10.1017/s0022377824000114

John M. Guthrie, Puchang Jiang, Jacob L. Roberts

{"title":"Calibrated heating rate measurements using electric-field-induced electron extraction in ultracold neutral plasmas","authors":"John M. Guthrie, Puchang Jiang, Jacob L. Roberts","doi":"10.1017/s0022377824000114","DOIUrl":"https://doi.org/10.1017/s0022377824000114","url":null,"abstract":"The heating rate of plasma electrons induced by external fields or other processes can be used as an experimental tool to measure fundamental plasma properties such as electrical conductivity or electron–ion collision rates. We have developed a technique that can measure electron heating rates in ultracold neutral plasmas (UNPs) with $sim 10,%$ precision while simultaneously referencing the measurement to a calibrated amount of heating. This technique uses a sequence of applied electric fields in four sections: to control the ratio of electrons to ions in the UNP; to provide a time for the application of fields that cause electron heating and subsequent thermalization of the electrons after the application of those fields; to extract electrons from the UNP using a method sensitive to electron temperature that allows the measurement of electron heating; and to extract the remaining electrons to measure the total electron (and therefore ion) number. The primary signal used to measure the heating rate is the measurement of the number of electrons that escape in the third section of the experiment as a larger number of escaping electrons indicates a larger amount of heating. We illustrate the use of this technique by measuring electron heating caused by high-frequency radiofrequency (RF) fields. In addition to the main technique, several subtechniques to calibrate the electron temperature, electron density, amount of heating and applied RF field amplitude were developed as well.","PeriodicalId":16846,"journal":{"name":"Journal of Plasma Physics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139760853","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

The magnetohydrodynamic equations in terms of waveframe variables 以波框变量表示的磁流体动力学方程

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-15 DOI: 10.1017/s0022377824000126

T. Van Doorsselaere, N. Magyar, M.V. Sieyra, M. Goossens

{"title":"The magnetohydrodynamic equations in terms of waveframe variables","authors":"T. Van Doorsselaere, N. Magyar, M.V. Sieyra, M. Goossens","doi":"10.1017/s0022377824000126","DOIUrl":"https://doi.org/10.1017/s0022377824000126","url":null,"abstract":"Generalising the Elsässer variables, we introduce the $Q$ -variables. These are more flexible than the Elsässer variables, because they also allow us to track waves with phase speeds different than the Alfvén speed. We rewrite the magnetohydrodynamics (MHD) equations with these $Q$ -variables. We consider also the linearised version of the resulting MHD equations in a uniform plasma, and recover the classical Alfvén waves, but also separate the fast and slow magnetosonic waves into upward- and downward-propagating waves. Moreover, we show that the $Q$ -variables may also track the upward- and downward-propagating surface Alfvén waves in a non-uniform plasma, displaying the power of our generalisation. In the end, we lay the mathematical framework for driving solar wind models with a multitude of wave drivers.","PeriodicalId":16846,"journal":{"name":"Journal of Plasma Physics","volume":"14 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761026","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

Ion transport and gas collision effects in a radio frequency quadrupole cooler: installation in the Eltrap solenoid and beam calculations 射频四极冷却器中的离子传输和气体碰撞效应：在埃尔特拉普螺线管中的安装和光束计算

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-12 DOI: 10.1017/s0022377823001484

M. Cavenago, M. Romé, G. Maero, F. Cavaliere, M. Comunian, M. Maggiore, A. Ruzzon

{"title":"Ion transport and gas collision effects in a radio frequency quadrupole cooler: installation in the Eltrap solenoid and beam calculations","authors":"M. Cavenago, M. Romé, G. Maero, F. Cavaliere, M. Comunian, M. Maggiore, A. Ruzzon","doi":"10.1017/s0022377823001484","DOIUrl":"https://doi.org/10.1017/s0022377823001484","url":null,"abstract":"Radio frequency quadrupole coolers (RFQCs) are very suitable to cool ion beams with moderate energy spread, typically ions of exotic nuclear species (like $^{132}$ Sn $^{1+}$ ) as in the Selective Production of Exotic Species project at the Laboratori Nazionali di Legnaro, whose ion source supplies 40 keV ions. Beam dynamics includes ion–gas collisions (with a balance of cooling and diffusion effects), acceleration and deceleration and radiofrequency confinement, which can be supplemented by static magnetic field effects. Insertion of a prototype RFQC in the solenoid of the Eltrap machine is also discussed here, with innovations in beam extraction and in modelling, now also based on stochastic equations. Practical consideration on gas pumping and voltage distribution are also included. Typical limits of RFQC are discussed, with special attention to the extracted beam root mean square emittance, which is shown to strongly depend not only on cooler parameters, but also on extraction optics.","PeriodicalId":16846,"journal":{"name":"Journal of Plasma Physics","volume":"5 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139760851","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

Electromagnetic oscillations and anomalous ion scattering in the helically symmetric multiple-mirror trap 螺旋对称多镜阱中的电磁振荡和反常离子散射

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-12 DOI: 10.1017/s0022377823001496

Mikhail S. Tolkachev, Anna A. Inzhevatkina, Anton V. Sudnikov, Ivan S. Chernoshtanov

{"title":"Electromagnetic oscillations and anomalous ion scattering in the helically symmetric multiple-mirror trap","authors":"Mikhail S. Tolkachev, Anna A. Inzhevatkina, Anton V. Sudnikov, Ivan S. Chernoshtanov","doi":"10.1017/s0022377823001496","DOIUrl":"https://doi.org/10.1017/s0022377823001496","url":null,"abstract":"The paper presents an investigation of the plasma fluctuation in the SMOLA helical mirror, which is suspected to be responsible for anomalous scattering. The helical mirror confinement is effective when the ion mean free path is equal to the helix pitch length. This condition can be satisfied in hot collisionless plasma only by anomalous scattering. The wave, which scatters the passing ions, is considered to receive energy from the trapped ions. The oscillations of the electric field in the helically symmetric plasma were observed in experiment. The oscillations have both regular highly correlated and chaotic components. The dependency of the regular component frequency on the Alfvén velocity is linear for $V_{rm A} < 2.8 times 10^6 text {m} text {s}^{-1}$ and constant for higher values. It is shown experimentally that the condition for the wave to be in phase resonance with the trapped ions is satisfied in a specific region of the plasma column for the highly correlated component. The amplitude of the chaotic component (up to $3 text {V} text {cm}^{-1}$ ) is higher than the estimated electric field required for the ion scattering.","PeriodicalId":16846,"journal":{"name":"Journal of Plasma Physics","volume":"16 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139760854","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

Transformation of a plasma boundary curvature into electrical impulses moving along a plasma surface 将等离子体边界曲率转化为沿等离子体表面移动的电脉冲

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-08 DOI: 10.1017/s0022377824000084

O.M. Gradov

引用次数: 0

Laser-machined two-stage nozzle optimised for laser wakefield acceleration 激光加工双级喷嘴，优化用于激光若飞加速

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-08 DOI: 10.1017/s0022377824000059

V. Tomkus, M. Mackevičiūtė, J. Dudutis, V. Girdauskas, M. Abedi-Varaki, P. Gečys, G. Račiukaitis

{"title":"Laser-machined two-stage nozzle optimised for laser wakefield acceleration","authors":"V. Tomkus, M. Mackevičiūtė, J. Dudutis, V. Girdauskas, M. Abedi-Varaki, P. Gečys, G. Račiukaitis","doi":"10.1017/s0022377824000059","DOIUrl":"https://doi.org/10.1017/s0022377824000059","url":null,"abstract":"In this paper, the modelling and manufacturing of a two-stage supersonic gas jet nozzle enabling the formation of adaptive plasma concentration profiles for injection and acceleration of electrons using few-cycle laser beams are presented. The stages are modelled using the rhoSimpleFoam algorithm of the OpenFOAM computational fluid dynamics software. The first 200–300 ${rm mu}$ m diameter nozzle stage is dedicated to 1 % N2 + He gas jet formation and electron injection. By varying the pressure between the first and second stages of the injectors, the electron injection location could be adjusted, and the maximum acceleration distance could be ensured. By changing the concentration of the nitrogen in the gas mixture, the charge of the accelerated electrons could be controlled. The second nozzle stage is designed for acceleration in fully ionised He or hydrogen gas and forms the optimal plasma concentration for bubble formation depending on the laser pulse energy, duration and focused beam diameter. In order to reduce the diameter of the plasma profile formed by the first nozzle and the concentration drop gap between the two nozzles, a one-side straight section was introduced in the first nozzle. The shock wave reflected from the straight section of the wall propagates parallel to the shock wave of the intersecting supersonic jets and ensures a minimal gap between the jets. The second-stage longitudinal plasma concentration profile could have an increasing gas density gradient to compensate for dephasing between the electron bunch and the plasma wave due to wave shortening with increasing plasma concentration.","PeriodicalId":16846,"journal":{"name":"Journal of Plasma Physics","volume":"12 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761031","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

Role of the edge electric field in the resonant mode-particle interactions and the formation of transport barriers in toroidal plasmas 边缘电场在环形等离子体中的共振模式-粒子相互作用和传输障碍形成中的作用

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-06 DOI: 10.1017/s0022377824000047

Giorgos Anastassiou, Panagiotis Zestanakis, Yiannis Antonenas, Eleonora Viezzer, Yannis Kominis

引用次数: 0

Hydrodynamic and kinetic representation of the microscopic classic dynamics at the transition on the macroscopic scale 宏观尺度过渡时期微观经典动力学的流体动力学和动力学表征

IF 2.5 3区物理与天体物理

Journal of Plasma Physics Pub Date : 2024-02-02 DOI: 10.1017/s0022377823000818

Pavel A. Andreev

引用次数: 0