Publications


Ion cyclotron resonance heating system in the RT-1 magnetospheric plasma

Nuclear Fusion 57 (2017)

M Nishiura, Y Kawazura, Z Yoshida, N Kenmochi, Y Yano, H Saitoh, M Yamasaki, T Mushiake, A Kashyap, N Takahashi, M Nakatsuka, A Fukuyama

© 2017 IAEA, Vienna. We have developed an ion cyclotron resonance frequency (ICRF) heating system for the Ring Trap 1 (RT-1) magnetospheric device. We excite slow waves from the polar region of the dipole magnetic field. The target helium plasma is produced by electron cyclotron heating. The electrons comprise high-temperature ( > 10 keV) and low-temperature ( < 100 eV) components with both typically exhibiting densities of the same order of magnitude. The ICRF heating causes an increase in the ion temperatures and toroidal flow velocities in the core plasma region. We observe appreciable temperature differences between the different ion species (main He + and impurity C 2+ ), suggesting a strong influence of the charge-exchange loss, which caused the bulk ions to remain relatively cold (∼20 eV) compared to the impurity ions (∼40 eV). By developing an electro-optical measurement system, we have measured the local wave electric field in the plasma.


The reverberation signatures of rotating disc winds in active galactic nuclei

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 471 (2017) 4798-4811

SW Mangham, C Knigge, JH Matthews, KS Long, SA Sim, N Higginbottom


Spatial and kinematic segregation in star-cluster merger remnants

Monthly Notices of the Royal Astronomical Society 466 (2017) 2895-2909

DR Cole, VP Debattista, AL Varri, M Adam, AC Seth

© 2016 The Authors. Globular clusters that exhibit chemical and dynamical complexity have been suggested to be the stripped nuclei of dwarf galaxies(e.g.M54, ω Cen).We use N-body simulations of nuclear star clusters forming via the mergers of star clusters to explore the persistence of substructure in the phase space. We find that the observed level of differentiation is difficult to reconcile with the observed if nuclear clusters form wholly out of the mergers of star clusters. Only the star clusters that merged most recently retain sufficiently distinct density and kinematics to be distinguishable from the rest of the nuclear cluster. In situ star formation must therefore be included to explain the observed properties of nuclear star clusters, in good agreement with previous results.


Gyrokinetic treatment of a grazing angle magnetic presheath

PLASMA PHYSICS AND CONTROLLED FUSION 59 (2017) ARTN 025015

A Geraldini, FI Parra, F Militello


Cosmic phylogeny: reconstructing the chemical history of the solar neighbourhood with an evolutionary tree

Monthly Notices of the Royal Astronomical Society 467 (2017) 1140-1153

P Jofré, P Das, J Bertranpetit, R Foley


Action principles for relativistic extended magnetohydrodynamics: A unified theory of magnetofluid models

PHYSICS OF PLASMAS 24 (2017) ARTN 022103

Y Kawazura, G Miloshevich, PJ Morrison


Experimental determination of the correlation properties of plasma turbulence using 2D BES systems

PLASMA PHYSICS AND CONTROLLED FUSION 59 (2017) ARTN 044008

MFJ Fox, AR Field, F van Wyk, Y-C Ghim, AA Schekochihin, MAST Team


Supergranulation and multiscale flows in the solar photosphere Global observations vs. a theory of anisotropic turbulent convection

ASTRONOMY & ASTROPHYSICS 599 (2017) ARTN A69

F Rincon, T Roudier, AA Schekochihin, M Rieutord


Electro-optic probe measurements of electric fields in plasmas.

The Review of scientific instruments 88 (2017) 023501-

M Nishiura, Z Yoshida, T Mushiake, Y Kawazura, R Osawa, K Fujinami, Y Yano, H Saitoh, M Yamasaki, A Kashyap, N Takahashi, M Nakatsuka, A Fukuyama

The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.


Designing uncertain optimization schemes for the economic assessment of stock energy-efficiency measures

Journal of Building Performance Simulation 10 (2017) 3-16

P Das, L Van Gelder, H Janssen, S Roels


A centrally heated dark halo for our Galaxy

Monthly Notices of the Royal Astronomical Society 465 (2017) 798-810

DR Cole, J Binney


The effect of tangential drifts on neoclassical transport in stellarators close to omnigeneity

PLASMA PHYSICS AND CONTROLLED FUSION 59 (2017) ARTN 055014

I Calvo, FI Parra, J Luis Velasco, JA Alonso


Electromagnetic zonal flow residual responses

JOURNAL OF PLASMA PHYSICS 83 (2017) ARTN 905830402

PJ Catto, FI Parra, I Pusztai


Ion-scale turbulence in MAST: anomalous transport, subcritical transitions, and comparison to BES measurements

PLASMA PHYSICS AND CONTROLLED FUSION 59 (2017) ARTN 114003

F van Wyk, EG Highcock, AR Field, CM Roach, AA Schekochihin, FI Parra, W Dorland


Quasar emission lines as probes of orientation: implications for disc wind geometries and unification

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 467 (2017) 2571-2584

JH Matthews, C Knigge, KS Long


Distribution functions for resonantly trapped orbits in the Galactic disc

Monthly Notices of the Royal Astronomical Society 471 (2017) 4314-4322

G Monari, B Famaey, J-B Fouvry, J Binney


Turbulent momentum transport due to the beating between different tokamak flux surface shaping effects

PLASMA PHYSICS AND CONTROLLED FUSION 59 (2017) ARTN 024007

J Ball, FI Parra


Observation of Oscillatory Radial Electric Field Relaxation in a Helical Plasma.

Physical review letters 118 (2017) 185002-

JA Alonso, E Sánchez, I Calvo, JL Velasco, KJ McCarthy, A Chmyga, LG Eliseev, T Estrada, R Kleiber, LI Krupnik, AV Melnikov, P Monreal, FI Parra, S Perfilov, AI Zhezhera

Measurements of the relaxation of a zonal electrostatic potential perturbation in a nonaxisymmetric magnetically confined plasma are presented. A sudden perturbation of the plasma equilibrium is induced by the injection of a cryogenic hydrogen pellet in the TJ-II stellarator, which is observed to be followed by a damped oscillation in the electrostatic potential. The waveform of the relaxation is consistent with theoretical calculations of zonal potential relaxation in a nonaxisymmetric magnetic geometry. The turbulent transport properties of a magnetic confinement configuration are expected to depend on the features of the collisionless damping of zonal flows, of which the present Letter is the first direct observation.


A low upper mass limit for the central black hole in the late-type galaxy NGC 4414

ASTRONOMY & ASTROPHYSICS 597 (2017) ARTN A18

S Thater, D Krajnovic, MA Bourne, M Cappellari, T de Zeeuw, E Emsellem, J Magorrian, RM McDermid, M Sarzi, G van de Ven


Symmetry breaking in MAST plasma turbulence due to toroidal flow shear

PLASMA PHYSICS AND CONTROLLED FUSION 59 (2017) ARTN 034002

MFJ Fox, F van Wyk, AR Field, Y-C Ghim, FI Parra, AA Schekochihin, MAST Team

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