#### W A Hornsby A R Bell R J Kingham R O Dendy

We present a novel code which solves the Vlasov-Fokker-Planck (VFP) equation in three dimensional magnetic turbulence using finite difference methods. The approach is distinct from particle tracking codes. The angular component of velocity space distribution function is represented by a spherical harmonic expansion drawing on an approach pioneered …

Published#### J.M. Dewhurst B. Hnat R.O. Dendy

The effect of finite Larmor radius on the transport of passive charged test particles moving in turbulent electrostatic fields is investigated. The turbulent field is governed by a flexible model which is able to produce turbulence where zonal flows are damped or free to self-generate. A subtle interplay between trapping in small scale vortices and…

Published#### R.M.Nicol S.C.Chapman R.O.Dendy

Wepresentgeneralizedstructurefunction(GSF)analysisof magneticandvelocityfieldfluctuationsmeasured insituinthesolarwindat ~ 1 AUwiththeACEspacecraft.Wedecomposethefluctuationsintodirectionsparalleland perpendiculartothemeanlocalbackgroundmagneticfield.GSFplotsbasedonthesequantitiesareshowntoprovideaclear indicatorofthespectralbreakbetweentheinertial…

Published#### R.O. Dendy

Information theory, applied directly to measured signals, yields new perspectives on, and quantitative knowledge of, the physics of strongly nonlinear and turbulent phenomena in plasmas. It represents a new and productive element of the topical research programmes that use modem techniques to characterise strongly nonlinear signals from plasmas, an…

Published#### J. A. Merrifield S. C. Chapman R. O. Dendy

Direct numerical simulations DNS provide a means to test phenomenological models for the scaling properties of intermittent MHD turbulence. The well-known model of She and Leveque, when generalized to MHD, is in good agreement with the DNS in three dimensions, however, it does not coincide with DNS in two dimensions 2D. This is resolved here using …

Published#### J. A. Merrifield T. D. Arber S. C. Chapman R. O. Dendy

Understanding the phenomenology captured in direct numerical simulation (DNS) of magnetohydrodynamic (MHD) turbulence rests upon models and assumptions concerning the scaling of field variables and dissipation. Here compressible MHD turbulence is simulated in two spatial dimensions by solving the isothermal equations of resistive MHD on a periodic …

Published#### N.C. Woolsey A.D. Ash C. Courtois R.O. Dendy C.D. Gregory I.M. Hall J. Howe

Laboratory experiment is an attractive method of exploring the plasma physics that may occur in solar and astrophysical shocks. An experiment enables repeated and detailed measurements of a plasma as the input conditions are adjusted. To form a scaled experiment of an astrophysical shock a plasma physics model of the shock is required, and the impo…

Published#### R. G. L. Vann R. O. Dendy M. P. Gryaznevich

Frequency sweeping (chirping) of high frequency magnetohydrodynamic modes is widely observed in tokamak plasmas. In this paper observations of chirping in neutral-beam-heated plasmas in the Mega-Amp Spherical Tokamak (MAST) [A. Sykes, R. J. Akers, L. C. Appel and et al. , Nucl. Fusion 41 , 1423 (2001)] are considered, and it is shown that these may…

Published#### J. A. Merrifield W.-C. Müller S. C. Chapman R. O. Dendy

The statistical properties of the dissipation process constrain the analysis of large scale numerical simulations of three-dimensional incompressible magnetohydrodynamic ( MHD ) turbulence, such as those of Biskamp and Müller [ Phys. Plasmas 7 , 4889 ( 2000 )] . The structure functions of the turbulent flow are expected to display statistical self…

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