Browsing by Subject "Plasmas"
Now showing items 1-20 of 24
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3D PiC code investigations of Auroral Kilometric Radiation mechanisms
(IOP Publishing Ltd., 2014) - Conference itemEfficient (similar to 1%) electron cyclotron radio emissions are known to originate in the X mode from regions of locally depleted plasma in the Earths polar magnetosphere. These emissions are commonly referred to as the ... -
3D pic simulations of collisionless shocks at lunar magnetic anomalies and their role in forming lunar swirls
(2016-10-18) - Journal articleInvestigation of the lunar crustal magnetic anomalies offers a comprehensive long-term data set of observations of small-scale magnetic fields and their interaction with the solar wind. In this paper a review of the ... -
Alfven wave phase-mixing and damping in the ion cyclotron range of frequencies
(2011-01) - Journal articleAims. We determine the effect of the Hall term in the generalised Ohm's law on the damping and phase mixing of Alfven waves in the ion cyclotron range of frequencies in uniform and non-uniform equilibrium plasmas. Methods. ... -
Coronal heating by the partial relaxation of twisted loops
(2013-02) - Journal articleContext: Relaxation theory offers a straightforward method for estimating the energy that is released when a magnetic field becomes unstable, as a result of continual convective driving. Aims: We present new results obtained ... -
The detection of numerous magnetic separators in a three-dimensional magnetohydrodynamic model of solar emerging flux
(2010-12-20) - Journal itemMagnetic separators in three-dimensional (3D) magnetic fields are believed to be often associated with locations of magnetic reconnection. In this preliminary study, we investigate this relationship using data from a ... -
Electrostatic activation of prebiotic chemistry in substellar atmospheres
(2014-04) - Journal articleCharged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an atmospheric plasma become negatively charged ... -
Evolution of field line helicity during magnetic reconnection
(2015-03) - Journal articleWe investigate the evolution of field line helicity for magnetic fields that connect two boundaries without null points, with emphasis on localized finite-B magnetic reconnection. Total ( relative) magnetic helicity is ... -
First comparison of wave observations from CoMP and AIA/SDO
(2013-08) - Journal articleContext. Waves have long been thought to contribute to the heating of the solar corona and the generation of the solar wind. Recent observations have demonstrated evidence of quasi-periodic longitudinal disturbances and ... -
Flare particle acceleration in the interaction of twisted coronal flux ropes
(2018-03-20) - Journal articleAims. The aim of this work is to investigate and characterise non-thermal particle behaviour in a three-dimensional (3D) magnetohydrodynamical (MHD) model of unstable multi-threaded flaring coronal loops. Methods. We have ... -
Inference of heating properties from "hot" non-flaring plasmas in active region cores. I. Single nanoflares
(2016-09-20) - Journal articleThe properties that are expected of “hot” non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the Enthalpy Based Thermal ... -
Inference of heating properties from "hot" non-flaring plasmas in active region cores. II. Nanoflare trains
(2016-12-20) - Journal articleDespite its prediction over two decades ago, the detection of faint, high-temperature ("hot") emission due to nanoflare heating in non-flaring active region cores has proved challenging. Using an efficient two-fluid ... -
Ionization in atmospheres of brown dwarfs and extrasolar planets VI : properties of large-scale discharge events
(2014-03-20) - Journal articleMineral clouds in substellar atmospheres play a special role as a catalyst for a variety of charge processes. If clouds are charged, the surrounding environment becomes electrically activated, and ensembles of charged ... -
Ionization in atmospheres of brown dwarfs and extrasolar planets. I. The role of electron avalanche
(2011-01-20) - Journal articleBrown dwarf and extrasolar planet atmospheres form clouds which strongly influence the local chemistry and physics. These clouds are globally neutral obeying dust-gas charge equilibrium which is, on short timescales, ... -
Ionization in atmospheres of brown dwarfs and extrasolar planets. V. Alfvén ionization
(2013-10-10) - Journal articleObservations of continuous radio and sporadic X-ray emission from low-mass objects suggest they harbor localized plasmas in their atmospheric environments. For low-mass objects, the degree of thermal ionization is insufficient ... -
Nonlinear wave propagation and reconnection at magnetic X-points in the Hall MHD regime
(2012-07) - Journal articleContext: The highly dynamical, complex nature of the solar atmosphere naturally implies the presence of waves in a topologically varied magnetic environment. Here, the interaction of waves with topological features such ... -
Particle acceleration at a reconnecting magnetic separator
(2015-02) - Journal articleWhile the exact acceleration mechanism of energetic particles during solar flares is (as yet) unknown, magnetic reconnection plays a key role both in the release of stored magnetic energy of the solar corona and the magnetic ... -
Particle acceleration at reconnecting separator current layers
(2016) - Journal articleThe aim of this work is to investigate and characterise particle behaviour in a 3D MHD model of a reconnecting magnetic separator. We use a relativistic guiding-centre test-particle code to investigate electron and proton ... -
Particle dynamics in a non-flaring solar active region model
(2016-03) - Journal articleThe aim of this work is to investigate and characterise particle behaviour in a (observationally-driven) 3D MHD model of the solar atmosphere above a slowly evolving, non-flaring active region. We use a relativistic ... -
Properties of the prominence magnetic field and plasma distributions as obtained from 3D whole-prominence fine structure modeling
(2016-08) - Journal articleAims. We analyze distributions of the magnetic field strength and prominence plasma (temperature, pressure, plasma beta, and mass) using the 3D whole-prominence fine structure model. Methods. The model combines a 3D magnetic ... -
Reference study to characterize plasma and magnetic properties of ultracool atmospheres
(2015-12-21) - Journal articleRadio and X-ray emission from brown dwarfs (BDs) suggest that an ionized gas and a magnetic field with a sufficient flux density must be present. We perform a reference study for late M-dwarfs (MD), BDs and giant gas planet ...