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Hot plasma is highly conductive in the direction parallel to a magnetic field. This often means that the electrical potential will be nearly constant along any given field line. When this is the case, the cross-field voltage drops in…

Plasma Physics · Physics 2024-05-29 E. J. Kolmes , I. E. Ochs , J. -M. Rax , N. J. Fisch

Plasma current filamentation of an ultrarelativistic electron beam impinging on an overdense plasma is investigated, with emphasis on radiation-induced electron polarization. Particle-in-cell simulations provide the classification and…

Plasma Physics · Physics 2023-01-18 Zheng Gong , Karen Z. Hatsagortsyan , Christoph H. Keitel

We propose a possible new mechanism for a strong and stable magnetic field of compact stars due to an instability in the presence of a chirality imbalance of electrons---the chiral plasma instability. A large chirality imbalance of…

High Energy Astrophysical Phenomena · Physics 2014-02-24 Akira Ohnishi , Naoki Yamamoto

In contrast to the broad stream of sustainable developments on fusion energy, new aspects are developed now by applying ultra-short, ultra-powerful laser pulses in a plasma-block ignition scheme by avoiding the well known difficulties of…

Plasma Physics · Physics 2014-12-16 Heinrich Hora

Design and modeling of a stellarator fusion reactor is a multidisciplinary effort that requires a tight integration between simulation of highly nonlinear multi-physics and representation of non-planar complex geometries. The critical…

Plasma Physics · Physics 2023-11-23 Merle Backmeyer , Nicolo Riva , Mika Lyly , Alexandre Halbach , Valtteri Lahtinen

A stellarator is said to be omnigeneous if all particles have vanishing average radial drifts. In omnigeneous stellarators, particles are perfectly confined in the absence of turbulence and collisions, whereas in non-omnigeneous…

Plasma Physics · Physics 2015-06-23 Felix I. Parra , Ivan Calvo , Per Helander , Matt Landreman

A neoclassically optimized compact stellarator with simple coils has been designed. The magnetic field of the new stellarator is generated by only four planar coils including two interlocking coils of elliptical shape and two circular…

Plasma Physics · Physics 2024-06-19 Guodong Yu , Zhichen Feng , Peiyou Jiang , Neil Pomphrey , Matt Landreman , GuoYong Fu

The benefits of thermionic emission from negatively biased electrodes for perpendicular electric field control in a magnetized plasma are examined through its combined effects on the sheath and on the plasma potential variation along…

Plasma Physics · Physics 2022-02-16 B. Trotabas , R. Gueroult

We propose a new mechanism to screen the electric field in the pulsar polar cap. Previous studies have shown that if an electron beam from the stellar surface is accelerated to energies high enough to create electron-positron pairs, the…

Astrophysics · Physics 2009-11-10 Katsuaki Asano , Fumio Takahara

In fusion devices, the geometry of the confining magnetic field has a significant impact on the instabilities that drive turbulent heat loss. This is especially true of stellarators, where the "trapped electron mode" (TEM) is stabilised if…

Aims. Many recent observations of pulsars and magnetars can be interpreted in terms of neutron stars (NS) with multipole electromagnetic fields. As a first approximation, we investigate the multipole magnetic and electric fields in the…

High Energy Astrophysical Phenomena · Physics 2020-07-07 S. Bonazzola , F. Mottez , J. Heyvaerts

The first achievement of highly radiating plasmas in negative triangularity is shown with an operational space featuring high core radiation at high Greenwald fraction obtained with the injection of reactor-relevant seeded gases. These…

It is possible to produce a ponderomotive effect in a plasma system without time-varying fields, if the plasma flows over spatial oscillations in the field. This can be achieved by superimposing a spatially oscillatory perturbation on a…

Plasma Physics · Physics 2024-11-20 E. J. Kolmes , N. J. Fisch

Stellarators are magnetic confinement devices under active development to deliver steady-state carbon-free fusion energy. Their design involves a high-dimensional, constrained optimization problem that requires expensive physics simulations…

A new experimental technique for investigating characteristics of plasma generated with plasmotrons in electrophysical installations was proposed. The technique involves a simultaneous registration of both radiation spectra and images of…

Plasma Physics · Physics 2007-05-23 V. Yu. Khomich , I. I. Kumkova , Yu. A. Zheleznov

The accumulation of impurities in the core of magnetically confined plasmas, resulting from standard collisional transport mechanisms, is a known threat to their performance as fusion energy sources. Whilst the axisymmetric tokamak systems…

Plasma Physics · Physics 2017-11-15 Sarah L. Newton , Per Helander , Albert Mollén , Håkan M. Smith

Research activities on laser plasma accelerators are paved by many significant breakthroughs. This review article provides an opportunity to show the incredible evolution of this field of research which has, in record time, allowed…

Plasma Physics · Physics 2011-12-22 V. Malka

We present a novel method for numerically finding quasi-isodynamic stellarator magnetic fields with excellent fast-particle confinement and extremely small neoclassical transport. The method works particularly well in configurations with…

The dynamics of electric field generation and radial acceleration of ions by a laser pulse of relativistic intensity propagating in an underdense plasma has been investigated using an one-dimensional electrostatic, ponderomotive model…

Plasma Physics · Physics 2008-07-30 A. Macchi , F. Ceccherini , F. Cornolti , S. Kar , M. Borghesi

A method is demonstrated to optimize a stellarator's geometry to eliminate magnetic islands and achieve other desired physics properties at the same time. For many physics quantities that have been used in stellarator optimization,…

Plasma Physics · Physics 2021-09-22 Matt Landreman , Bharat Medasani , Caoxiang Zhu