-
MCTrans++: a 0-D model for centrifugal mirrors J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-23 Nick R. Schwartz, Ian G. Abel, Adil B. Hassam, Myles Kelly, Carlos A. Romero-Talamás
The centrifugal mirror confinement scheme incorporates supersonic rotation of a plasma into a magnetic mirror device. This concept has been shown experimentally to drastically decrease parallel losses and increase plasma stability as compared with prior axisymmetric mirrors. MCTrans++ is a dimensionless (0-D) scoping tool which rapidly models experimental operating points in the Centrifugal Mirror
-
Global fluid turbulence simulations in the scrape-off layer of a stellarator island divertor J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-22 B. Shanahan, D. Bold, B. Dudson
Isothermal fluid turbulence simulations have been performed in the edge and scrape-off layer (SOL) of an analytic stellarator configuration with an island divertor, thereby providing numerical insight into edge turbulence in regions around islands in a stellarator. The steady-state transport follows the a curvature drive that is inverse to the major radius ( $1/R$ ) toward the outboard side, but large
-
Simulations of radiatively cooled magnetic reconnection driven by pulsed power J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-19 Rishabh Datta, Aidan Crilly, Jeremy P. Chittenden, Simran Chowdhry, Katherine Chandler, Nikita Chaturvedi, Clayton E. Myers, William R. Fox, Stephanie B. Hansen, Chris A. Jennings, Hantao Ji, Carolyn C. Kuranz, Sergey V. Lebedev, Dmitri A. Uzdensky, Jack D. Hare
Magnetic reconnection is an important process in astrophysical environments, as it reconfigures magnetic field topology and converts magnetic energy into thermal and kinetic energy. In extreme astrophysical systems, such as black hole coronae and pulsar magnetospheres, radiative cooling modifies the energy partition by radiating away internal energy, which can lead to the radiative collapse of the
-
The Okubo–Weiss-type topological criteria in two-dimensional magnetohydrodynamic flows J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-16 B.K. Shivamoggi, G.J.F. van Heijst, L.P.J. Kamp
The Okubo–Weiss (Okubo, Deep-Sea Res., vol. 17, issue 3, 1970, pp. 445–454; Weiss, Physica D, vol. 48, issue 2, 1991, pp. 273–294) criterion has been widely used as a diagnostic tool to divide a two-dimensional (2-D) hydrodynamical flow field into hyperbolic and elliptic regions. This paper considers extension of these ideas to 2-D magnetohydrodynamic (MHD) flows, and presents an Okubo–Weiss-type criterion
-
Density jump for oblique collisionless shocks in pair plasmas: physical solutions J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-16 Antoine Bret, Colby C. Haggerty, Ramesh Narayan
Collisionless shocks are frequently analysed using the magnetohydrodynamics (MHD) formalism, even though MHD assumes a small mean free path. Yet, isotropy of pressure, the fruit of binary collisions and assumed in MHD, may not apply in collisionless shocks. This is especially true within a magnetized plasma, where the field can stabilize an anisotropy. In a previous article (Bret & Narayan, J. Plasma
-
The maximum-J property in quasi-isodynamic stellarators J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-16 E. Rodríguez, P. Helander, A.G. Goodman
Some stellarators tend to benefit from favourable average magnetic curvature for trapped particles when the plasma pressure is sufficiently high. This so-called maximum- $J$ property has several positive implications, such as good fast-particle confinement, magnetohydrodynamic stability and suppression of certain trapped-particle instabilities. This property cannot be attained in quasisymmetric stellarators
-
Effects observed in numerical simulation of high-beta plasma with hot ions in an axisymmetric mirror machine J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-12 I.S. Chernoshtanov, I.G. Chernykh, G.I. Dudnikova, M.A. Boronina, T.V. Liseykina, V.A. Vshivkov
We present the results of numerical simulation by two-dimensional hybrid particle-in-cell code of high-beta plasma with hot ions in an axisymmetric mirror machine. Two particular effects are discussed: the self-rotating of plasma with Maxwellian ions in regime of diamagnetic confinement and the excitation of axisymmetric magnetosonic waves in a high-beta plasma with sloshing ions.
-
Optimization of nonlinear turbulence in stellarators J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-11 P. Kim, S. Buller, R. Conlin, W. Dorland, D.W. Dudt, R. Gaur, R. Jorge, E. Kolemen, M. Landreman, N.R. Mandell, D. Panici
We present new stellarator equilibria that have been optimized for reduced turbulent transport using nonlinear gyrokinetic simulations within the optimization loop. The optimization routine involves coupling the pseudo-spectral GPU-native gyrokinetic code GX with the stellarator equilibrium and optimization code DESC. Since using GX allows for fast nonlinear simulations, we directly optimize for reduced
-
Energetic particle tracing in optimized quasi-symmetric stellarator equilibria J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-05 P.A. Figueiredo, R. Jorge, J. Ferreira, P. Rodrigues
Recent developments in the design of magnetic confinement fusion devices have allowed the construction of exceptionally optimized stellarator configurations. The near-axis expansion in particular has been proven to enable the construction of magnetic configurations with good confinement properties while taking only a fraction of the usual computation time to generate optimized magnetic equilibria.
-
Asymptotic quasisymmetric high-beta three-dimensional magnetohydrodynamic equilibria near axisymmetry J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-05 Wrick Sengupta, Nikita Nikulsin, Rahul Gaur, Amitava Bhattacharjee
Quasisymmetry (QS), a hidden symmetry of the magnetic field strength, is known to support nested flux surfaces and provide superior particle confinement in stellarators. In this work, we study the ideal magnetohydrodynamic (MHD) equilibrium and stability of high-beta plasma in a large-aspect-ratio stellarator. In particular, we show that the lowest-order description of a near-axisymmetric equilibrium
-
Study of the pellet ablation cloud using the tomography technique for two-directional simultaneous photography in GAMMA 10/PDX J. Plasma Phys. (IF 2.5) Pub Date : 2024-04-05 M. Yoshikawa, Y. Nakashima, J. Kohagura, Y. Shima, S. Kobayashi, R. Minami, N. Ezumi, M. Sakamoto
The pellet ablation mechanism is an interesting subject for plasma fuelling in fusion plasmas. In GAMMA 10/PDX, pellet injection experiments for higher density plasma production are planned to conduct detached plasma experiments in the higher density plasma condition. We measured the pellet ablation cloud by using the two-directional simultaneous photography system in GAMMA 10/PDX. The tomography reconstruction
-
Transient versus steady-state solutions: a qualitative study J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-27 D. Van Eester, E.A. Lerche, E. Pawelec, E. Solano
In view of the ultimate goal of producing long-lasting quasi-stationary discharges required for future fusion power stations, the numerical study of steady-state solutions of equations describing the particle and energy balance rightfully gets ample attention. Transient states may, however, differ significantly from the steady state ultimately reached and will – in practice – impact on the actual fate
-
Effects of multi-dimensionality and energy exchange on electrostatic current-driven plasma instabilities and turbulence J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-27 Wai Hong Ronald Chan, Kentaro Hara, Iain D. Boyd
Large-amplitude current-driven plasma instabilities, which can transition to the Buneman instability, were observed in one-dimensional simulations to generate high-energy back-streaming ions. We investigate the saturation of multi-dimensional plasma instabilities and its effects on energetic ion formation. Such ions directly impact spacecraft thruster lifetimes and are associated with magnetic reconnection
-
The residual flow in well-optimized stellarators J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-21 G.G. Plunk, P. Helander
The gyrokinetic theory of the residual flow, in the electrostatic limit, is revisited, with optimized stellarators in mind. We consider general initial conditions for the problem, and identify cases that lead to a non-zonal residual electrostatic potential, i.e. one having a significant component that varies within a flux surface. We investigate the behaviour of the ‘intermediate residual’ in stellarators
-
The gyrokinetic dispersion relation of microtearing modes in collisionless toroidal plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-21 B.D.G. Chandran, A.A. Schekochihin
We solve the linearized gyrokinetic equation, quasineutrality condition and Ampere's law to obtain the dispersion relation of microtearing modes (MTMs) in collisionless low- $\beta$ toroidal plasmas. Consistent with past studies, we find that MTMs are driven unstable by the electron temperature gradient and that this instability drive is mediated by magnetic drifts. The dispersion relation that we
-
Charged particle collisionless transport near the X-point of the two-wire model J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-19 Bin Ahn, Yegeon Lim, Hoiyun Jeong, Hae June Lee, Gyung Jin Choi, Y.-C. Ghim
Collisionless charged particle motion and its transport in the two-wire model (TWM) with no axial magnetic fields is investigated numerically. The TWM configuration contains a magnetic X-point, and single particle motions in such a field have two conserved quantities: the total kinetic energy and the base field line value which is a quantity derived from the axial canonical momentum. As gyrating particles
-
Loss-cone stabilization in rotating mirrors: thresholds and thermodynamics J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-15 E.J. Kolmes, I.E. Ochs, N.J. Fisch
In the limit of sufficiently fast rotation, rotating mirror traps are known to be stable against the loss-cone modes associated with conventional (non-rotating) mirrors. This paper calculates how quickly a mirror configuration must rotate in order for several of these modes to be stabilized (in particular, the high-frequency convective loss cone, drift cyclotron loss cone and Dory–Guest–Harris modes)
-
Mean-field transport equations and energy theorem for plasma edge turbulent transport J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-15 Reinart Coosemans, Wouter Dekeyser, Martine Baelmans
This paper establishes a mean-field equation set and an energy theorem to provide a theoretical basis in view of the development of self-consistent, physics-based turbulent transport models for mean-field transport codes. A rigorous averaging procedure identifies the exact form of the perpendicular turbulent fluxes which are modelled by ad hoc diffusive terms in mean-field transport codes, next to
-
Experimental issues of energy balance in open magnetic trap J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-14 Elena I. Soldatkina, Andrey K. Meyster, Dmitry V. Yakovlev, Peter A. Bagryansky
The paper presents an overview of experimental results of an investigation of different energy loss channels in the gas dynamic trap (GDT), which is a magnetic mirror plasma confinement device in the Budker Institute of Nuclear Physics. Energy losses along magnetic field lines are considered as well as losses onto radial limiters, which restrict the plasma column radius and provide its magnetohydrodynamic
-
Development of a new magnetic mirror device at the Korea Advanced Institute of Science and Technology J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-12 D. Oh, M. Choe, G. Baek, D. Kim, B. K. Jung, K. J. Chung, I. Kourakis, C. Sung
A new magnetic mirror machine named KAIMIR (KAIST mirror) has been designed and constructed at the Korea Advanced Institute of Science and Technology (KAIST) to study mirror plasma physics and simulate the boundary regions of magnetic fusion plasmas such as in a tokamak. The purpose of this paper is to introduce the characteristics and initial experimental results of KAIMIR. The cylindrical vacuum
-
Nonlinear electron scattering by electrostatic waves in collisionless shocks J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-07 Sergei R. Kamaletdinov, Ivan Y. Vasko, Anton V. Artemyev
We present a theoretical analysis of electron pitch-angle scattering by ion-acoustic electrostatic fluctuations present in the Earth's bow shock and, presumably, collisionless shocks in general. We numerically simulate electron interaction with a single wave packet to demonstrate the scattering through phase bunching and phase trapping and quantify electron pitch-angle scattering in dependence on the
-
Modelling a thrust imparted by a highly ionized magnetic nozzle rf plasma thruster J. Plasma Phys. (IF 2.5) Pub Date : 2024-03-07 Kazunori Takahashi
Influence of the local-ionization-induced neutral depletion on the thrust imparted by the magnetic nozzle plasma thruster is discussed by simply considering reduction of the neutral density due to the ionization in the thruster model combining the global source model and the one-dimensional magnetic nozzle model. When increasing the rf power, it is shown that the increase rate of the plasma density
-
Modulational instability of the interacting electron whistlers and magnetosonic perturbations J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-28 Jiao-Jiao Cheng, Fang-Ping Wang, Zhong-Zheng Li, Wen-Shan Duan
A modulational instability of nonlinearly interacting electron whistlers and magnetosonic perturbations is studied in the present paper. For typical parameters, there is no modulational instability. However, modulational instability appears in special cases. For example, when the whistler wavenumber is small enough, there is modulational instability. Its growth rate decreases as the angle between the
-
Accelerating self-modulated nonlinear waves in weakly and strongly magnetized relativistic plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-27 Felipe A. Asenjo
It is known that a nonlinear Schrödinger equation describes the self-modulation of a large amplitude circularly polarized wave in relativistic electron–positron plasmas in the weakly and strongly magnetized limits. Here, we show that such an equation can be written as a modified second Painlevé equation, producing accelerated propagating wave solutions for those nonlinear plasmas. This solution even
-
Magnetic fields with general omnigenity J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-27 Daniel W. Dudt, Alan G. Goodman, Rory Conlin, Dario Panici, Egemen Kolemen
Omnigenity is a desirable property of toroidal magnetic fields that ensures confinement of trapped particles. Confining charged particles is a basic requirement for any fusion power plant design, but it can be difficult to satisfy with the non-axisymmetric magnetic fields used by the stellarator approach. Every ideal magnetohydrodynamic equilibrium previously found to approximate omnigenity has been
-
Confinement of transitioning particles in bi-helical Wendelstein-type configurations J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-26 A.V. Tykhyy, Ya.I. Kolesnichenko
Recently, stochastic motion of 3.5-MeV alpha particles with orbits that vary between locally trapped and locally passing states (transitioning particles) in a Helias reactor was observed numerically. This validated the theoretical predictions that (i) the stochastic diffusion represents a mechanism of considerable delayed loss of fast ions in quasi-isodynamic stellarators and (ii) it is possible to
-
Turbulence spreading effects on the ELM size and SOL width J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-23 Nami Li, X.Q. Xu, P.H. Diamond, Y.F. Wang, X. Lin, N. Yan, G.S. Xu
BOUT++ turbulence simulations were performed to investigate the impact of turbulence spreading on the edge localized mode (ELM) size and divertor heat flux width $({\lambda _q})$ broadening in small ELM regimes. This study is motivated by EAST experiments. BOUT++ linear simulations of a pedestal radial electric field (Er) scan show that the dominant toroidal number mode (n) shifts from high-n to low-n
-
Emission of terahertz pulses from near-critical plasma slab under action of p-polarized laser radiation J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-21 A.A. Frolov
The theory of the terahertz (THz) waves emission from a near-critical plasma slab under the action of the focused p-polarized laser pulse is developed. The spectral, angular and energy characteristics of the THz signal are studied as functions of the focusing degree and the incidence angle of laser radiation, as well as the density and thickness of the plasma slab. It is shown that the extremely strong
-
Effects of guard and boom on needle Langmuir probes studied with particle-in-cell simulations J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-21 S.M. Brask, S. Marholm, W.J. Miloch, R. Marchand
We investigate the effects of different guard geometries on the currents to needle-type Langmuir probes. The results are based on particle-in-cell numerical simulations. We show that if the guard length is less than 6–8 Debye lengths there can be a significant effect on the currents to the probe. A guard radius should not be larger than the Debye length, otherwise it can also significantly affect the
-
Transverse magnetic field effects on the high-voltage pulsed discharge plasma in helium J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-21 C. Chen, K. M. Rabadanov, N. A. Ashurbekov, C. Yuan, A. M. Shakhrudinov
This study investigates the effect of a transverse magnetic field on high-voltage pulsed discharge in helium at a pressure of 30 Torr. A simple two-dimensional fluid model that describes the high-voltage pulsed discharge in helium in a transverse weak magnetic field (B = 0.4 T) is presented, which uses an empirical relation to account for the magnetic field. The results of using the empirical relation
-
Calibrated heating rate measurements using electric-field-induced electron extraction in ultracold neutral plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-15 John M. Guthrie, Puchang Jiang, Jacob L. Roberts
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
-
Trivelpiece–Gould modes and low-frequency electron–ion instability of non-neutral plasma J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-15 Yuriy N. Yeliseyev
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
-
The magnetohydrodynamic equations in terms of waveframe variables J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-15 T. Van Doorsselaere, N. Magyar, M.V. Sieyra, M. Goossens
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
-
Nonlinear Hall effect in a stationary cylinder with a radial heat flux J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-15 G.S. Bisnovatyi-Kogan, M.V. Glushikhina
A conducting cylinder with a uniform magnetic field along its axis and radial temperature gradient is considered at the stationary state. At large temperature gradients the azimuthal Hall electrical current creates an axial magnetic field whose strength may be comparable with the original one. It is shown that the magnetic field, generated by the azimuthal Hall current, leads to the decrease of a magnetic
-
Electromagnetic oscillations and anomalous ion scattering in the helically symmetric multiple-mirror trap J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-12 Mikhail S. Tolkachev, Anna A. Inzhevatkina, Anton V. Sudnikov, Ivan S. Chernoshtanov
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
-
Ion transport and gas collision effects in a radio frequency quadrupole cooler: installation in the Eltrap solenoid and beam calculations J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-12 M. Cavenago, M. Romé, G. Maero, F. Cavaliere, M. Comunian, M. Maggiore, A. Ruzzon
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)
-
Laser-machined two-stage nozzle optimised for laser wakefield acceleration J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-08 V. Tomkus, M. Mackevičiūtė, J. Dudutis, V. Girdauskas, M. Abedi-Varaki, P. Gečys, G. Račiukaitis
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
-
Transformation of a plasma boundary curvature into electrical impulses moving along a plasma surface J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-08 O.M. Gradov
The self-consistent propagation of electrical impulses and of the accompanying distortions of the electron surface in the framework of a cold plasma model with a sharp boundary has been described with help of a derived system of two equations. The method of ‘shallow water theory’ has been applied for the case of bounded plasma and deriving an equation with which to link the spatial and temporal structures
-
Role of the edge electric field in the resonant mode-particle interactions and the formation of transport barriers in toroidal plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-06 Giorgos Anastassiou, Panagiotis Zestanakis, Yiannis Antonenas, Eleonora Viezzer, Yannis Kominis
The impact of an edge radial electric field on the particle orbits and the orbital spectrum in an axisymmetric toroidal magnetic equilibrium is investigated using a guiding centre canonical formalism. Poloidal and bounce/transit-averaged toroidal precession frequencies are calculated, highlighting the role of the radial electric field. The radial electric field is shown to drastically modify the resonance
-
A two-dimensional numerical study of ion-acoustic turbulence J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-02 Zhuo Liu, Ryan White, Manaure Francisquez, Lucio M. Milanese, Nuno F. Loureiro
We investigate the linear and nonlinear evolution of the current-driven ion-acoustic instability in a collisionless plasma via two-dimensional (2-D) Vlasov–Poisson numerical simulations. We initialise the system in a stable state and gradually drive it towards instability with an imposed, weak external electric field, thus avoiding physically unrealisable super-critical initial conditions. A comprehensive
-
Hydrodynamic and kinetic representation of the microscopic classic dynamics at the transition on the macroscopic scale J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-02 Pavel A. Andreev
An open problem of the derivation of the relativistic Vlasov equation for systems of charged particles moving with velocities up to the speed of light and creating the electromagnetic field in accordance with the full set of the Maxwell equations is considered. Moreover, the method of derivation is illustrated on the non-relativistic kinetic model. Independent derivation of the relativistic hydrodynamics
-
Space–time structure of weak magnetohydrodynamic turbulence J. Plasma Phys. (IF 2.5) Pub Date : 2024-02-01 Augustus A. Azelis, Jean C. Perez, Sofiane Bourouaine
The two-time energy spectrum of weak magnetohydrodynamic turbulence is found by applying a wave-turbulence closure to the cumulant hierarchy constructed from the dynamical equations. Solutions are facilitated via asymptotic expansions in terms of the small parameter $\varepsilon$ , describing the ratio of time scales corresponding to Alfvénic propagation and nonlinear interactions between counter-propagating
-
Polarization effects in higher-order guiding-centre Lagrangian dynamics J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-30 Alain J. Brizard
The extended guiding-centre Lagrangian equations of motion are derived by the Lie-transform perturbation method under the assumption of time-dependent and inhomogeneous electric and magnetic fields that satisfy the standard guiding-centre space–time orderings. Polarization effects are introduced into the Lagrangian dynamics by the inclusion of the polarization drift velocity in the guiding-centre velocity
-
Resonant excitation of terahertz surface magnetoplasmons by optical rectification over a rippled surface of n-type indium antimonide J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-25 Rohit Kumar Srivastav, A. Panwar
We analysed the excitation of a surface magnetoplasmon wave by the mode conversion of a p-polarized laser beam over a rippled semiconductor (n-type)-free space interface. The pump surface magnetoplasmon wave exerts a ponderomotive force on the free electrons in the semiconductor, imparting a linear oscillatory velocity at the laser modulation frequency to them. This linear oscillatory velocity couples
-
The gap-size influence on the excitation of magnetorotational instability in cylindricTaylor–Couette flows J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-23 G. Rüdiger, M. Schultz
The excitation conditions of the magnetorotational instability (MRI) are studied for axially unbounded Taylor–Couette (TC) flows of various gap widths between the cylinders. The cylinders are considered as made from both perfect-conducting or insulating material and the conducting fluid with a finite but small magnetic Prandtl number rotates with a quasi-Keplerian velocity profile. The solutions are
-
Development of the ambipolar electric field in a compressed current sheet and the impact on magnetic reconnection J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-19 Ami M. DuBois, Chris Crabtree, Gurudas Ganguli
Satellite data analysis of a compressed gyro-scale current sheet prior to magnetic reconnection in the magnetotail shows that electrostatic lower hybrid waves localized to the region of a transverse ambipolar electric field at the centre of the current sheet are driven by $\boldsymbol{E} \times \boldsymbol{B}$ velocity shear and result from compression. The presence and location of shear-driven waves
-
On hydromagnetic wave interactions in collisionless, high-β plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-19 S. Majeski, M.W. Kunz
We describe the interaction of parallel-propagating Alfvén waves with ion-acoustic waves and other Alfvén waves, in magnetized, high- $\beta$ collisionless plasmas. This is accomplished through a combination of analytical theory and numerical fluid simulations of the Chew–Goldberger–Low (CGL) magnetohydrodynamic (MHD) equations closed by Landau-fluid heat fluxes. An asymptotic ordering is employed
-
Prospects for a high-field, compact break-even axisymmetric mirror (BEAM) and applications J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-17 C.B. Forest, J.K. Anderson, D. Endrizzi, J. Egedal, S. Frank, K. Furlong, M. Ialovega, J. Kirch, R.W. Harvey, B. Lindley, Yu.V. Petrov, J. Pizzo, T. Qian, K. Sanwalka, O. Schmitz, J. Wallace, D. Yakovlev, M. Yu
This paper explores the feasibility of a break-even-class mirror referred to as BEAM (break-even axisymmetric mirror): a neutral-beam-heated simple mirror capable of thermonuclear-grade parameters and $Q\sim 1$ conditions. Compared with earlier mirror experiments in the 1980s, BEAM would have: higher-energy neutral beams, a larger and denser plasma at higher magnetic field, both an edge and a core
-
Self-organization in the avalanche, quench and dissipation of a molecular ultracold plasma J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-17 K.L. Marroquín, R. Wang, A. Allahverdian, N. Durand-Brousseau, S. Colombini, F. Kogel, J.S. Keller, T. Langen, E.R. Grant
Spontaneous avalanche to plasma begins in the core of an ellipsoidal Rydberg gas of nitric oxide. Ambipolar expansion of NO $^+$ draws energy from avalanche-heated electrons. Then, cycles of long-range resonant electron transfer from Rydberg molecules to ions equalize their relative velocities. This sequence of steps gives rise to a remarkable mechanics of self-assembly, in which the kinetic energy
-
Coupling multi-fluid dynamics equipped with Landau closures to the particle-in-cell method J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-17 Rouven Lemmerz, Mohamad Shalaby, Timon Thomas, Christoph Pfrommer
The particle-in-cell (PIC) method is successfully used to study magnetized plasmas. However, this requires large computational costs and limits simulations to short physical run times and often to set-ups of less than three spatial dimensions. Traditionally, this is circumvented either via hybrid-PIC methods (adopting massless electrons) or via magneto-hydrodynamic-PIC methods (modelling the background
-
Electron cyclotron resonance during plasma initiation J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-15 C. Albert Johansson, Pavel Aleynikov
Electron-cyclotron resonance heating (ECRH) is the main heating mechanism in the Wendelstein 7-X (W7-X) stellarator. Although second-harmonic ECRH (X2) has been used routinely for plasma startup, startup at third harmonic (X3) is known to be much more difficult. In this work, we investigate the energy gain of particles during nonlinear wave–particle interaction for conditions relevant to second- and
-
Improved numerical simulation model for nuclear reaction rate calculations in high-speed plasma collisions J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-11 Bo Zeng, Zijia Zhao, Xiaohu Yang, Shaowu Yang, Yanyun Ma
Beam–target reactions in fusion plasmas play an important role in both magnetic confinement fusion and inertial confinement fusion in the condition of low-density plasmas with high-velocity interactions. The traditional method for calculating beam–target reaction rate neglects the transport process of incident particles in inhomogeneous plasmas, leading to errors providing that the temperature and
-
Design and construction of the near-earth space plasma simulation system of the Space Plasma Environment Research Facility J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-11 W. Ling, C. Jing, J. Wan, A. Mao, Q. Xiao, J. Guan, J. Cheng, C. Liu, P. E
Our earth is immersed in the near-earth space plasma environment, which plays a vital role in protecting our planet against the solar-wind impact and influencing space activities. It is significant to investigate the physical processes dominating the environment, for deepening our scientific understanding of it and improving the ability to forecast the space weather. As a crucial part of the National
-
On the role of numerical diffusivity in MHD simulations of global accretion disc dynamos J. Plasma Phys. (IF 2.5) Pub Date : 2024-01-05 C.J. Nixon, C.C.T. Pringle, J.E. Pringle
Observations, mainly of outbursts in dwarf novae, imply that the anomalous viscosity in highly ionized accretion discs is magnetic in origin and requires that the plasma ${\beta \sim 1}$ . Until now, most simulations of the magnetic dynamo in accretion discs have used a local approximation (known as the shearing box). While these simulations demonstrate the possibility of a self-sustaining dynamo,
-
Proton and helium ions acceleration in near-critical density gas targets by short-pulse Ti:Sa PW-class laser J. Plasma Phys. (IF 2.5) Pub Date : 2023-12-28 J.L. Henares, P. Puyuelo-Valdes, C. Salgado-López, J.I. Apiñaniz, P. Bradford, F. Consoli, D. de Luis, M. Ehret, F. Hannachi, R. Hernández-Martín, A. Huber, L. Lancia, M. Mackeviciute, A. Maitrallain, J.-R. Marquès, J.A. Pérez-Hernández, C. Santos, J.J. Santos, V. Stankevic, M. Tarisien, V. Tomkus, L. Volpe, G. Gatti
The ability to quickly refresh gas-jet targets without cycling the vacuum chamber makes them a promising candidate for laser-accelerated ion experiments at high repetition rate. Here we present results from the first high repetition rate ion acceleration experiment on the VEGA-3 PW-class laser at CLPU. A near-critical density gas-jet target was produced by forcing a 1000 bar H $_2$ and He gas mix through
-
Guiding centre motion for particles in a ponderomotive magnetostatic end plug J. Plasma Phys. (IF 2.5) Pub Date : 2023-12-28 T. Rubin, J.M. Rax, N.J. Fisch
The Hamiltonian dynamics of a single particle in a rotating plasma column, interacting with an magnetic multipole is perturbatively solved for up to second order, using the method of Lie transformations. First, the exact Hamiltonian is expressed in terms of canonical action-angle variables, and then an approximate integrable Hamiltonian is introduced, using another set of actions and angles, which
-
Rotating Alfvén waves in rotating plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2023-12-28 J.-M. Rax, R. Gueroult, N.J. Fisch
Angular momentum coupling between a rotating magnetized plasma and torsional Alfvén waves carrying orbital angular momentum (OAM) is examined. It is demonstrated not only that rotation is the source of Fresnel–Faraday rotation – or orbital Faraday rotation effects – for OAM-carrying Alfvén waves, but also that angular momentum from an OAM-carrying Alfvén wave can be transferred to a rotating plasma
-
A simple model for internal transport barrier induced by fishbone in tokamak plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2023-12-28 Zhaoyang Liu, Guoyong Fu
Fishbone bursts have been observed to strongly correlate to internal transport barrier (ITB) formation in a number of tokamak devices. A simple model incorporating the fishbone dynamics and ion pressure gradient evolution is proposed in order to investigate the key physics parameters assisting the triggering of ITB. The time evolution of fishbone is described by the well-known predator–prey model.
-
Intermittency of density fluctuations and zonal-flow generation in MAST edge plasmas J. Plasma Phys. (IF 2.5) Pub Date : 2023-12-27 A. Sladkomedova, I. Cziegler, A.R. Field, A.A. Schekochihin, D. Dunai, P.G. Ivanov, the MAST-U Team and the EUROfusion MST1 Team
The properties of the edge ion-scale turbulence are studied using the beam emission spectroscopy (BES) diagnostic on MAST. Evidence of the formation of large-scale high-amplitude coherent structures, filamentary density blobs and holes, 2–4 cm inside the plasma separatrix is presented. Measurements of radial velocity and skewness of the density fluctuations indicate that density holes propagate radially
-
Loss and revival of coherence in the interaction between a positron beam and a photon field J. Plasma Phys. (IF 2.5) Pub Date : 2023-12-27 F. Castelli, S. Cialdi, G. Costantini, R. Ferragut, M. Giammarchi, G. Gittini, M. Leone, G. Maero, S. Olivares, M. Romé, A. Simonetto, V. Toso
We study the interaction between a positron beam in the single-particle regime in an interferometric configuration and a microwave electromagnetic field. We discuss the conditions under which quantum interference can be affected by the field and we outline its possible experimental study in the framework of QUantum interferometry and gravitation with Positrons and LASers (QUPLAS) experiment.