5 results match your criteria: "Chalmers University of Technology and EURATOM-VR Association[Affiliation]"

Mode conversion of waves in the ion-cyclotron frequency range in magnetospheric plasmas.

Phys Rev Lett

September 2013

Department of Applied Physics, Chalmers University of Technology and Euratom-VR Association, SE-41296 Göteborg, Sweden and Laboratory for Plasma Physics, ERM/KMS, Association "EURATOM-Belgian State," TEC Partner, BE-1000 Brussels, Belgium.

Waves in the ion-cyclotron range of frequencies with linear polarization detected by satellites can be useful for estimating the heavy ion concentrations in planetary magnetospheres. These waves are considered to be driven by mode conversion (MC) of the fast magnetosonic waves at the ion-ion hybrid resonances. In this Letter, we derive analytical expressions for the MC efficiency and tunneling of waves through the MC layer.

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Ion runaway in lightning discharges.

Phys Rev Lett

July 2013

Department of Applied Physics, Nuclear Engineering, Chalmers University of Technology and Euratom-VR Association, Göteborg SE-41296, Sweden.

Runaway ions can be produced in plasmas with large electric fields, where the accelerating electric force is augmented by the low mean ionic charge due to the imbalance between the number of electrons and ions. Here we derive an expression for the high-energy tail of the ion distribution function in lightning discharges and investigate the energy range that the ions can reach. We also estimate the corresponding energetic proton and neutron production due to fusion reactions.

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Runaway positrons in fusion plasmas.

Phys Rev Lett

June 2012

Department of Applied Physics, Nuclear Engineering, Chalmers University of Technology and Euratom-VR Association, Göteborg, Sweden.

Runaway positrons can be produced in the presence of runaway electron avalanches in magnetized plasmas. In this Letter, we determine the positron distribution, the fraction of runaway positrons, and the parametric dependences of their synchrotron radiation spectrum. We show that the maximum production occurs around γ(e)≃30, where γ(e) is the Lorentz factor of the fast electrons.

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The problem of random motion of charged particles in an external magnetic field is studied under the assumption that the Langevin sources produce anisotropic diffusion in velocity space and the friction force is dependent on the direction of particle motion. It is shown that in the case under consideration, the kinetic equation describing particle transitions in phase space is reduced to the equation with a Fokker-Planck collision term in the general form (non-isotropic friction coefficient and nonzero off-diagonal elements of the diffusion tensor in the velocity space). The solution of such an equation has been obtained and the explicit form of the transition probability is found.

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Approximate solutions of two-way diffusion equations.

Phys Rev E Stat Nonlin Soft Matter Phys

March 2002

Department of Electromagnetics, Chalmers University of Technology and EURATOM-VR Association, SE-41296 Göteborg, Sweden.

In this paper, a general and systematic scheme is formulated for finding approximate solutions of two-way diffusion equations. This expansion scheme is valid for arbitrary mean-free path and can be carried out to any desired accuracy. Its potential is demonstrated by constructing approximate solutions for two problems concerning the kinetics of an electron beam, and the accuracy is found to be very good even when only a few terms are included in the expansion.

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