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Very large DC and AC electric fields cannot be sustained between conducting electrodes because of volume gas breakdown and/or surface field emission. However, very large potential fields are now routinely generated in plasma structures such…

Plasma Physics · Physics 2023-07-26 Jean-Marcel Rax , Renaud Gueroult , Nathaniel J. Fisch

Charged particles at the crust of compact stars may be ejected and accelerated by the electric field generated due to the rotation of the magnetized star. For neutron or hybrid stars, the negatively charged particles are usually electrons,…

High Energy Astrophysical Phenomena · Physics 2020-10-28 Debojoti Kuzur , Rupamoy Bhattacharyya , Ritam Mallick

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 center canonical formalism. Poloidal and bounce/transit-averaged…

The design of divertor targets and baffles for optimal heat and particle exhaust from magnetically confined fusion plasmas requires a combination of fast, low-fidelity models (such as EMC3-lite [1]) for scoping studies and high-fidelity…

Computational Physics · Physics 2025-02-14 H. Frerichs , D. Boeyaert , Y. Feng , K. A. Garcia

The development of stellarators that use permanent magnet arrays to shape their confining magnetic fields has been a topic of recent interest, but the requirements for how such magnets must be shaped, manufactured, and assembled remain to…

Plasma Physics · Physics 2020-09-04 K. C. Hammond , C. Zhu , T. Brown , K. Corrigan , D. A. Gates , M. Sibilia

The formation of ultracold molecules via stimulated emission followed by a radiative deexcitation cascade in the presence of a static electric field is investigated. By analyzing the corresponding cross sections, we demonstrate the…

Quantum Physics · Physics 2007-06-06 Rosario González-Férez , Michael Mayle , Peter Schmelcher

A novel plasma state has been found in the presence of a uniform applied axial magnetic field in periodic cylindrical geometry. This state is driven electrostatically by helical electrodes, providing a driving field that depends on radius…

Plasma Physics · Physics 2017-08-15 Cihan Akçay , John M. Finn , Richard A. Nebel , Daniel C. Barnes

The probability of photon emission of a charged particle traversing a strong field becomes modified if vacuum polarization is considered. This feature is important for fundamental quantum electrodynamics processes present in extreme…

High Energy Physics - Phenomenology · Physics 2023-05-24 M. Jirka , P. Sasorov , S. V. Bulanov

The activity of magnetars is believed to be powered by colossal magnetic energy reservoirs. We sketch an evolutionary picture in which internal field evolution in magnetars generates a twisted corona, form which energy may be released…

High Energy Astrophysical Phenomena · Physics 2016-06-22 S. K. Lander

Optimised stellarators and other magnetic-confinement devices having the property that the average magnetic curvature is favourable for all particle orbits are called maximum-$J$ devices, and have recently been shown to be immune to…

Plasma Physics · Physics 2017-08-15 G. G. Plunk , J. W. Connor , P. Helander

Strong magnetic fields and plasmas are intrinsically linked in both terrestrial laboratory experiments and in space phenomena. One of the most profound consequences of that is the change in relationship between the frequency and the wave…

We investigate the strong electric current sheet that develops at the tip of the pulsar closed line region through time dependent three-dimensional numerical simulations of a rotating magnetic dipole. We show that curvature radiation from…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Ioannis Contopoulos , Constantinos Kalapotharakos

A new type of stellarator divertor is found. It has features of both a nonresonant divertor (A. Punjabi and A. H. Boozer, Phys. Plasmas 27, 012503 (2020)) as well as a resonant divertor. It has the outermost confining surface with sharp…

Plasma Physics · Physics 2024-03-06 Alkesh Punjabi , Allen H. Boozer

We demonstrate the ability to excite atoms at well-defined, programmable locations in a magneto-optical trap, either to the continuum (ionisation), or to a Rydberg state. To this end, excitation laser light is shaped into arbitrary…

Accelerator-based light sources such as storage rings and free-electron lasers use relativistic electron beams to produce intense radiation over a wide spectral range for fundamental research in physics, chemistry, materials science,…

Accelerator Physics · Physics 2015-06-19 Erik Hemsing , Gennady Stupakov , Dao Xiang , Alexander Zholents

Magnetic fields can be created in stably stratified (non-convective) layers in a differentially rotating star. A magnetic instability in the toroidal field (wound up by differential rotation) replaces the role of convection in closing the…

Astrophysics · Physics 2009-11-07 H. C. Spruit

The reduction of magnetic forces on electromagnetic coils is an important consideration in the design of high-field devices such as the stellarator or tokamak. Unfortunately, these forces may be too time-consuming to evaluate by…

Plasma Physics · Physics 2024-10-15 Siena Hurwitz , Matt Landreman , Alan Kaptanoglu

The physics of plasmas containing positive and negative ions is discussed with special attention to the recently produced pair-ion plasma containing ions of equal mass and opposite charge. The effects of the density gradient in the…

Plasma Physics · Physics 2009-11-13 J. Vranjes , D. Petrovic , B. P. Pandey , S. Poedts

It has been known since decades that the alignment of a beam of high-energy electrons with particular crystal directions involves a significant increase of bremsstrahlung radiation emission. This enhancement lies at the conceptual…

The problem of creating well-collimated beams of atoms escaping from a trap is studied. This problem is of high importance for the realization of atom lasers. Nonadiabatic dynamics of neutral atoms in nonuniform magnetic fields, typical of…

Condensed Matter · Physics 2007-05-23 V. I. Yukalov , E. P. Yukalova