The Physics of Field-Aligned Currents
|
|
- Imogene Hill
- 5 years ago
- Views:
Transcription
1 The Physics of Field-Aligned Currents Andrew N. Wright UNIVERSITY OF ST ANDREWS
2 Magnetospheric Current Circuit There is a rich structure of currents flowing parallel (j ) and perpendicular (j ) to the magnetic field (B). Magnetopause current Ring current Ionospheric currents Region 1 and 2 currents ULF Alfvén waves Magnetopause current Region 1 current Ionospheric Pedersen current Region 2 current Partial ring current [Figure from NASA GSFC.] View from tail First Prev Next Last Go Back Full Screen Close Quit
3 Quasi-Neutrality and Current Continuity The Ampère-Maxwell equation states Taking the divergence yields B/µ 0 = j + ε 0 E t. E 0 = j + ε 0. t Using Gauss s Law, E = ρ /ε 0 (where ρ = net charge density) we find Quasi-neutrality (ρ 0) j + ρ t = 0. j 0: Currents are self-closing. The displacement current (ε 0 E/ t) is neglected. ρ 0 means (n e n i )/n e 1. Debye length is ε 0 kt e /e 2 n e 100 m (magnetosphere), 0.01 m (ionosphere).
4 Some Magnetohydrodynamic Driving Mechanisms Imposed velocity shear [Rönnmark, GRL, 1998] Fundamental standing (ULF) Alfvén wave Axisymmetric oscillation of magnetic shells b φ and u φ components only j and j currents
5 Generation of j (MHD description) Single fluid MHD momentum equation ρ dv dt = j B p + F Solve for j ( j = ρ dv ) dt + p F B B 2 Since j = 0 we find j j s + j = 0, j = along B j ds The field-aligned current (j ) flows to maintain quasi-neutrality (ρ 0)
6 What is j microscopically? Net drift of charged particles parallel to B Consider the parallel component of the equation of motion for a charged particle (uniform B), dv dt = qe m. E can be used to establish a field-aligned current. Since m e /m i 1 the electrons are more mobile, and carry most of the parallel current: j ev e In MHD m e /m i 0: electrons are represented by a massless charge-neutralizing fluid (E 0) To generate j requires E How does E arise? Causal interpretation in ideal MHD difficult since E/ t has been neglected
7 Guiding centre description of particle motion Particles execute a circular trajectory about B whose centre drifts. Valid when Gyroradius background scale length Gyroperiod background timescale Guiding centre drifts parallel to B arise from E and magnetic mirror force m dv dt = qe + µ B The magnetic moment µ = mv 2 /2B is a constant of motion. Guiding centre drifts perpendicular to B (can depend upon q, m and energy) arise from Grad B drift B curvature drift Polarization drift (E(t)) E B drift
8 Generation of j (particle description) In general, given E(r, t) and B(r, t), electrons and ions drift relative to one another current can flow net charge density is likely to develop ρ 0 As ρ becomes non-zero, E and E change to satisfy and influence the particle motion Effect of even a small E : E = ρ /ε 0 electrons are accelerated parallel to B j is established parallel electron motion acts to reduce ρ the plasma remains quasi-neutral (ρ 0) Interestingly, E still satisfies B/µ 0 = j + ε 0 E t, even though the last term is still negligible. First Prev Next Last Go Back Full Screen Close Quit
9 Ring Current and Standing Alfvén Wave j v e v e electrons j E +ve E v i j E ve E j j electrons electrons j j ions j E E v e B 0 B 0 v e electrons j Looking earthward from the tail Warm ion cloud drifts westward Slight charge imbalance generates E, electron motion and j Snapshot of Alfvén wave current circuit E(t) in equatorial region produces polarization drift Ions drift across L-shells leading to charge imbalance and subsequent j
10 To steal ideas from one person is plagiarism... To steal from many is research.
11 Magnetosphere-Ionosphere Equilibrium Near the Earth A simple equilibrium has a total ion number density comprising: constant magnetospheric contribution (n M 1 cm 3 ) exponentially decreasing ionospheric contribution (n I cm 3, scale height km) If n = n I + n M and B is dipolar, B/n has a peak at a few thousand km altitude below B/n peak: B/n exp(+r/h) above B/n peak: B/n 1/r 3 First Prev Next Last Go Back Full Screen Close Quit
12 Upward and Downward Currents and the Auroral Acceleration Region Upward Current: magnetospheric electrons precepitated visible aurora Downward Current: ionospheric electrons evacuated to magnetosphere Current-Voltage (energy) relations for upward and downward currents? [Marklund et al., Nature, 2001.]
13 Gyrotropic Electron Vlasov Equation: f(s, v, v, t) Retains information of ionospheric and magnetospheric electron populations f t + v f s ( ee m e + v2 2B B s ) f v + v v 2B B s f v = 0 s = field-aligned coordinate. For a steady current E = φ E = φ/ s. Constants of motion are total energy: W = 1 2 m ev 2 eφ magnetic moment: µ = m e v 2 /2B Solve for f(s, v, v ) with v (W, µ), v (W, µ) Liouville s Theorem (f is constant along an electron trajectory) n e = n i φ(s) and j = e v fd 3 v Solution relates current flow to potential drop along the field line
14 Upward Current (downgoing electrons) Assuming a potential drop φ m : map magnetospheric electrons down to the ionosphere using W and µ to identify the loss cone. Calculate j at the ionosphere in terms of φ m : ( kt j n 0 e 1 eφ ) m 2πm e kt The Knight relation [Planet. Space Sci., 1973]. Useful for interpreting data (electron energies) Good for incorporating in global modelels Knight s solution says little about quasi-neutrality or φ(s) variation E needed to overcome mirror force v Where does acceleration occur? E e v e acceleration region
15 Upward Current Quasi-Neutral Solution Quasi-neutral solution for previous B/n variation gives [Cran-McGreehin, 2006] Plots of normalized potential and E along B. (Ionosphere at s = 0) Below B/n peak, ambipolar E traps ionospheric electrons Above B/n peak, E helps precitating electrons overcome the mirror force adjust mirroring magnetospheric electrons to maintain quasi-neutrality
16 Downward Current (upgoing electrons) Some ionospheric electrons are accelerated upward into the magnetosphere Ionosphere Magnetosphere Velocity parallel to B Beam l m lc l e l p l 0 [Cran-McGreehin and Wright, JGR, 2005a,b] Field-aligned coordinate is l. Important locations are l p : location of the B/n peak l c : ionospheric electron trapping point/beam emergence height
17 Downward Current Quasi-Neutral Solution Quasi-neutral solution for previous B/n variation gives [Cran-McGreehin and Wright, JGR, 2005a,b] Plots of normalized potential and E along B. (Ionosphere at s = 0) Electron acceleration is centred around the B/n peak Ionospheric j of µam 2 correspond to potential drops along B of kev
18 Analytical Current-Voltage Relation (Downward Current) The potential drop (φ m ) depends upon j and n at the B/n peak, as well as the magnetospheric electron temperature (T ) [Cran-McGreehin and Wright, JGR, 2005b] If j 2 p m e/2kt n 2 pe 2 < 1.7 then φ m 3 2 ( j 2 p m1/2 e n p e 5/2 kt ) ( ) 1 j 4 p m2 3 ekt n 4 pe 7 + j2 p m e 6n 2 pe 3 If j 2 p m e/2kt n 2 pe 2 > 1.7 then φ m kt e ln ( j 2 p m e n 2 pe 2 kt Approximations accurate to at least 5% May only need one or two terms ) + j2 p m e 2n 2 pe 3 + kt e
19 A conclusion is what you come to when you re tired of thinking. First Prev Next Last Go Back Full Screen Close Quit
20 Conclusion and Summary Field aligned currents are an integral part of the magnetosphere arise from both large scale driving and internal particle drifts carried mainly by electrons (accelerated by E ) Downgoing electrons excite the aurora Details of φ(s) and E (s) are different for upward and downward currents (but B/n peak location is important) Analytical Current-Voltage relations available
21 Future Work Allow ions to move and modify background density Address time-dependence Combine large and small scale physics of acceleration region (FAST) Other acceleration mechanisms (wave-particle interactions?) Interpret with governing equations
22 Optical auroral emissions: CANOPUS First Prev Next Last Go Back Full Screen Close Quit LATITUDE (EDFL) MPA (Altitude at 110 km) UT/ nm 9.4 kr 0.2 kr TIME (MINUTE) Auroral emissions are modulated with the Alfvén wave period [Xu, Liu, Samson] Emissions excited by kev energy electron precipitation Electron acceleration is an integral part of the Alfven wave Electron energization not described in single fluid MHD Latitudinal scale 200 km
23 FAST: Field-Aligned Electron Motion and j Downward j : upward moving ionospheric electron beam Upward j : downward moving magnetospheric electron beam
Global MHD Eigenmodes of the Outer Magnetosphere
Global MHD Eigenmodes of the Outer Magnetosphere Andrew Wright UNIVERSITY OF ST ANDREWS Magnetospheric Structure: Cavities and Waveguides The Earth s magnetosphere is structured by magnetic fields and
More informationSingle Particle Motion in a Magnetized Plasma
Single Particle Motion in a Magnetized Plasma Aurora observed from the Space Shuttle Bounce Motion At Earth, pitch angles are defined by the velocity direction of particles at the magnetic equator, therefore:
More informationWave-particle interactions in dispersive shear Alfvèn waves
Wave-particle interactions in dispersive shear Alfvèn waves R. Rankin and C. E. J. Watt Department of Physics, University of Alberta, Edmonton, Canada. Outline Auroral electron acceleration in short parallel
More informationSingle particle motion and trapped particles
Single particle motion and trapped particles Gyromotion of ions and electrons Drifts in electric fields Inhomogeneous magnetic fields Magnetic and general drift motions Trapped magnetospheric particles
More informationSingle Particle Motion
Single Particle Motion C ontents Uniform E and B E = - guiding centers Definition of guiding center E gravitation Non Uniform B 'grad B' drift, B B Curvature drift Grad -B drift, B B invariance of µ. Magnetic
More informationUppsala universitet Institutionen för astronomi och rymdfysik Anders Eriksson
Tentamen för Rymdfysik I 2006-08-15 Uppsala universitet Institutionen för astronomi och rymdfysik Anders Eriksson Please write your name on all papers, and on the first page your address, e-mail and phone
More informationxkcd.com It IS about physics. It ALL is.
xkcd.com It IS about physics. It ALL is. Introduction to Space Plasmas The Plasma State What is a plasma? Basic plasma properties: Qualitative & Quantitative Examples of plasmas Single particle motion
More informationcos 6 λ m sin 2 λ m Mirror Point latitude Equatorial Pitch Angle Figure 5.1: Mirror point latitude as function of equatorial pitch angle.
Chapter 5 The Inner Magnetosphere 5.1 Trapped Particles The motion of trapped particles in the inner magnetosphere is a combination of gyro motion, bounce motion, and gradient and curvature drifts. In
More informationRelationship of Oscillating Aurora to Substorms and Magnetic Field Line Resonances
Proceedings ICS-6, 2002 Relationship of Oscillating Aurora to Substorms and Magnetic Field Line Resonances James A. Wanliss and Robert Rankin Department of Physics, University of Alberta Edmonton, AB,
More informationGlobal Monitoring of the Terrestrial Ring Current
Global Monitoring of the Terrestrial Ring Current Stefano Orsini Istituto di Fisica dello Spazio Interplanetario, CNR ROMA, Italy with the fruitful help of Anna Milillo and of all other colleagues of the
More informationSingle particle motion
Single particle motion Plasma is a collection of a very large number of charged particles moving in, and giving rise to, electromagnetic fields. Before going to the statistical descriptions, let us learn
More informationElectron pressure effects on driven auroral Alfvén waves
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110,, doi:10.1029/2004ja010610, 2005 Electron pressure effects on driven auroral Alfvén waves Jörgen Vedin and Kjell Rönnmark Department of Physics, Umeå University,
More informationSW103: Lecture 2. Magnetohydrodynamics and MHD models
SW103: Lecture 2 Magnetohydrodynamics and MHD models Scale sizes in the Solar Terrestrial System: or why we use MagnetoHydroDynamics Sun-Earth distance = 1 Astronomical Unit (AU) 200 R Sun 20,000 R E 1
More informationCharged particle motion in external fields
Chapter 2 Charged particle motion in external fields A (fully ionized) plasma contains a very large number of particles. In general, their motion can only be studied statistically, taking appropriate averages.
More informationImage credit: NASA/JPL
Image credit: NASA/JPL Aleia Paan Dr. Carol Pat Dr. Kurt Retherford 1 Motivation Investigation of the connection between the variabilit in Ganmede footprint brightness and in Ganmede s auroral emissions
More informationPlasma collisions and conductivity
e ion conductivity Plasma collisions and conductivity Collisions in weakly and fully ionized plasmas Electric conductivity in non-magnetized and magnetized plasmas Collision frequencies In weakly ionized
More informationIntroduction to Plasma Physics
Introduction to Plasma Physics Hartmut Zohm Max-Planck-Institut für Plasmaphysik 85748 Garching DPG Advanced Physics School The Physics of ITER Bad Honnef, 22.09.2014 A simplistic view on a Fusion Power
More informationSpace Physics. An Introduction to Plasmas and Particles in the Heliosphere and Magnetospheres. May-Britt Kallenrode. Springer
May-Britt Kallenrode Space Physics An Introduction to Plasmas and Particles in the Heliosphere and Magnetospheres With 170 Figures, 9 Tables, Numerous Exercises and Problems Springer Contents 1. Introduction
More informationDispersive Media, Lecture 7 - Thomas Johnson 1. Waves in plasmas. T. Johnson
2017-02-14 Dispersive Media, Lecture 7 - Thomas Johnson 1 Waves in plasmas T. Johnson Introduction to plasmas as a coupled system Magneto-Hydro Dynamics, MHD Plasmas without magnetic fields Cold plasmas
More informationEarth s Magnetosphere
Earth s Magnetosphere General Description of the Magnetosphere Shape Pressure Balance The Earth s Magnetic Field The Geodynamo, Magnetic Reversals, Discovery Current Systems Chapman Ferraro Cross Tail
More informationPlasma Interactions with Electromagnetic Fields
Plasma Interactions with Electromagnetic Fields Roger H. Varney SRI International June 21, 2015 R. H. Varney (SRI) Plasmas and EM Fields June 21, 2015 1 / 23 1 Introduction 2 Particle Motion in Fields
More informationESS 200C Aurorae. Lecture 15
ESS 200C Aurorae Lecture 15 The record of auroral observations dates back thousands of years to Greek and Chinese documents. The name aurora borealis (latin for northern dawn) was coined in 1621 by P.
More informationMagnetic Reconnection
Magnetic Reconnection? On small scale-lengths (i.e. at sharp gradients), a diffusion region (physics unknown) can form where the magnetic field can diffuse through the plasma (i.e. a breakdown of the frozenin
More informationFluid equations, magnetohydrodynamics
Fluid equations, magnetohydrodynamics Multi-fluid theory Equation of state Single-fluid theory Generalised Ohm s law Magnetic tension and plasma beta Stationarity and equilibria Validity of magnetohydrodynamics
More informationThe role Alfvén waves in the generation of Earth polar auroras
The role Alfvén waves in the generation of Earth polar auroras Fabrice Mottez Laboratoire Univers et THéories (LUTH) - Obs. Paris-Meudon - CNRS - Univ. Paris Diderot Abstract. The acceleration of electrons
More informationqb 3 B ( B) r 3 e r = 3 B r e r B = B/ r e r = 3 B ER 3 E r 4
Magnetospheric Physics - Homework solution, /8/14 18 Gradient and curvature drift (a) A single proton has a parallel and perpendicular energy of 1 kev. Compute (B B) /B 3 and determine the instantaneous
More informationIonosphères planétaires (introduction)
Ionosphères planétaires (introduction) email: arnaud.zaslavsky@obspm.fr Structure de l atmosphère terrestre Temperature gradients determined by IR radiation from Earth (low altitude Troposhere) And from
More informationMacroscopic plasma description
Macroscopic plasma description Macroscopic plasma theories are fluid theories at different levels single fluid (magnetohydrodynamics MHD) two-fluid (multifluid, separate equations for electron and ion
More informationPlasmas as fluids. S.M.Lea. January 2007
Plasmas as fluids S.M.Lea January 2007 So far we have considered a plasma as a set of non intereacting particles, each following its own path in the electric and magnetic fields. Now we want to consider
More informationTentamen för kursen Rymdfysik (1FA255)
Tentamen för kursen Rymdfysik (1FA255) 2017-10-24 Uppsala universitet Institutionen för fysik och astronomi Avdelningen för astronomi och rymdfysik Anders Eriksson Answers should be provided in Swedish
More informationThe Structure of the Magnetosphere
The Structure of the Magnetosphere The earth s magnetic field would resemble a simple magnetic dipole, much like a big bar magnet, except that the solar wind distorts its shape. As illustrated below, the
More informationAURORA: GLOBAL FEATURES
AURORA: GLOBAL FEATURES Jean-Claude Gérard LPAP Université de Liège OUTLINE - collisional processes involved in the aurora - remote sensing of auroral electron energy - Jupiter - Saturn MOP meeting - 2011
More informationMagnetospherically-Generated Ionospheric Electric Fields
Magnetospherically-Generated Ionospheric Electric Fields Stanislav Sazykin Rice University sazykin@rice.edu June 26, 2005 Sazykin--Ionospheric E-Fields--CEDAR Student Workshop 1 Overall Magnetospheric
More informationFigure 1.1: Ionization and Recombination
Chapter 1 Introduction 1.1 What is a Plasma? 1.1.1 An ionized gas A plasma is a gas in which an important fraction of the atoms is ionized, so that the electrons and ions are separately free. When does
More informationIn-Situ vs. Remote Sensing
In-Situ vs. Remote Sensing J. L. Burch Southwest Research Institute San Antonio, TX USA Forum on the Future of Magnetospheric Research International Space Science Institute Bern, Switzerland March 24-25,
More informationThe chiming of Saturn s magnetosphere at planetary periods
The chiming of Saturn's magnetosphere at planetary periods. Gabby Provan with help from David Andrews and Stan Cowley The chiming of Saturn s magnetosphere at planetary periods G. Provan, D. J. Andrews
More informationA Note on A-C Effects on MHD Dynamo in the Earth's Low-Latitude Magnetospheric Boundary Layer. Senkichi SHIBUYA
Research Note J. Geomag. Geoelectr., 43, 65-70,1991 A Note on A-C Effects on MHD Dynamo in the Earth's Low-Latitude Magnetospheric Boundary Layer Senkichi SHIBUYA Faculty of Science, Yamagata University,
More informationPROBLEM SET. Heliophysics Summer School. July, 2013
PROBLEM SET Heliophysics Summer School July, 2013 Problem Set for Shocks and Particle Acceleration There is probably only time to attempt one or two of these questions. In the tutorial session discussion
More information2/8/16 Dispersive Media, Lecture 5 - Thomas Johnson 1. Waves in plasmas. T. Johnson
2/8/16 Dispersive Media, Lecture 5 - Thomas Johnson 1 Waves in plasmas T. Johnson Introduction to plasma physics Magneto-Hydro Dynamics, MHD Plasmas without magnetic fields Cold plasmas Transverse waves
More informationMotion of Charged Particles in Fields
Chapter Motion of Charged Particles in Fields Plasmas are complicated because motions of electrons and ions are determined by the electric and magnetic fields but also change the fields by the currents
More informationThe Auroral Zone: Potential Structures in Field and Density Gradients
The Auroral Zone: Potential Structures in Field and Density Gradients David Schriver May 8, 2007 Global Kinetic Modeling: week 10 Foreshock (week 3) Auroral zone (week 7) (week 8) Radiation Belt (week
More informationxkcd.com It IS about physics. It ALL is.
xkcd.com It IS about physics. It ALL is. Introduction to Space Plasmas! The Plasma State What is a plasma? Basic plasma properties: Qualitative & Quantitative Examples of plasmas! Single particle motion
More informationSingle Particle Motion
Single Particle Motion Overview Electromagnetic fields, Lorentz-force, gyration and guiding center, drifts, adiabatic invariants. Pre-requisites: Energy density of the particle population smaller than
More informationDiscussion of Magnetosphere-ionosphere coupling at Jupiter
Discussion of Magnetosphere-ionosphere coupling at Jupiter arry H. Mauk The Johns Hopkins University Applied Physics Laboratory Fran agenal University of Colorado LASP Auroral Workshop; 7-8 March 2016;
More informationMagnetospheric Physics - Homework, 02/21/ Local expansion of B: Consider the matrix B = (1)
Magnetospheric Physics - Homework, //4 4. Local expansion of B: Consider the matrix B α x γ δ x γ α y δ y β x β y α z () with constant parameters α i, β i, δ i, γ, and γ for the expansion of the magnetic
More informationElectrics. Electromagnetism
Electrics Electromagnetism Electromagnetism Magnetism is associated with charges in motion (currents): microscopic currents in the atoms of magnetic materials. macroscopic currents in the windings of an
More informationWaves in plasma. Denis Gialis
Waves in plasma Denis Gialis This is a short introduction on waves in a non-relativistic plasma. We will consider a plasma of electrons and protons which is fully ionized, nonrelativistic and homogeneous.
More informationGyrokinetic simulations of magnetic fusion plasmas
Gyrokinetic simulations of magnetic fusion plasmas Tutorial 2 Virginie Grandgirard CEA/DSM/IRFM, Association Euratom-CEA, Cadarache, 13108 St Paul-lez-Durance, France. email: virginie.grandgirard@cea.fr
More informationHeliophysics in Atmospheres
Heliophysics in Atmospheres Thermosphere-Ionosphere Response to Geomagnetic Storms Tim Fuller-Rowell NOAA Space Weather Prediction Center and CIRES University of Colorado Atmospheres Gravitationally bound
More informationChapter 12. Magnetism and Electromagnetism
Chapter 12 Magnetism and Electromagnetism 167 168 AP Physics Multiple Choice Practice Magnetism and Electromagnetism SECTION A Magnetostatics 1. Four infinitely long wires are arranged as shown in the
More informationSimulating the Ionosphere, one electron at a time.
Simulating the Ionosphere, one electron at a time. Meers Oppenheim CEDAR June 2016 Research supported by NSF, NASA, AFRL, and DOE Grants What? Plasma Physics Particle-in-Cell Simulations Two Examples:
More informationSolar-Wind/Magnetosphere Coupling
Solar-Wind/Magnetosphere Coupling Joe Borovsky Space Science Institute --- University of Michigan 1. Get a feeling for how the coupling works 2. Get an understanding of how reconnection works 3. Look at
More informationModeling Interactions between the Magnetosphere, Ionosphere & Thermosphere. M.Wiltberger NCAR/HAO
Modeling Interactions between the Magnetosphere, Ionosphere & Thermosphere M.Wiltberger NCAR/HAO Outline Overview of MIT circuit Modeling Magnetospheric impacts on the Ionosphere Energetic Particle Fluxes
More informationTURBULENT TRANSPORT THEORY
ASDEX Upgrade Max-Planck-Institut für Plasmaphysik TURBULENT TRANSPORT THEORY C. Angioni GYRO, J. Candy and R.E. Waltz, GA The problem of Transport Transport is the physics subject which studies the physical
More informationDavid versus Goliath 1
David versus Goliath 1 or A Comparison of the Magnetospheres between Jupiter and Earth 1 David and Goliath is a story from the Bible that is about a normal man (David) who meets a giant (Goliath) Tomas
More informationand another with a peak frequency ω 2
Physics Qualifying Examination Part I 7-Minute Questions September 13, 2014 1. A sealed container is divided into two volumes by a moveable piston. There are N A molecules on one side and N B molecules
More informationLectures on basic plasma physics: Hamiltonian mechanics of charged particle motion
Lectures on basic plasma physics: Hamiltonian mechanics of charged particle motion Department of applied physics, Aalto University March 8, 2016 Hamiltonian versus Newtonian mechanics Newtonian mechanics:
More informationPhysicsAndMathsTutor.com 1
PhysicsAndMathsTutor.com 1 1. Millikan determined the charge on individual oil droplets using an arrangement as represented in the diagram. The plate voltage necessary to hold a charged droplet stationary
More informationPlasma Astrophysics Chapter 1: Basic Concepts of Plasma. Yosuke Mizuno Institute of Astronomy National Tsing-Hua University
Plasma Astrophysics Chapter 1: Basic Concepts of Plasma Yosuke Mizuno Institute of Astronomy National Tsing-Hua University What is a Plasma? A plasma is a quasi-neutral gas consisting of positive and negative
More informationLecture Note 1. 99% of the matter in the universe is in the plasma state. Solid -> liquid -> Gas -> Plasma (The fourth state of matter)
Lecture Note 1 1.1 Plasma 99% of the matter in the universe is in the plasma state. Solid -> liquid -> Gas -> Plasma (The fourth state of matter) Recall: Concept of Temperature A gas in thermal equilibrium
More informationEECS 117 Lecture 13: Method of Images / Steady Currents
EECS 117 Lecture 13: Method of Images / Steady Currents Prof. Niknejad University of California, Berkeley University of California, Berkeley EECS 217 Lecture 13 p. 1/21 Point Charge Near Ground Plane Consider
More informationUNH Modeling for RENU2
UNH Modeling for RENU2 RENU 2 Science Team Meeting I Brent Sadler University of New Hampshire (Model: Antonius Otto, UAF) 1 CHAMP satellite Plot showing 8 orbits of the CHAMP satellite, at 400 km altitude,
More informationPlasma Physics Prof. Vijayshri School of Sciences, IGNOU. Lecture No. # 38 Diffusion in Plasmas
Plasma Physics Prof. Vijayshri School of Sciences, IGNOU Lecture No. # 38 Diffusion in Plasmas In today s lecture, we will be taking up the topic diffusion in plasmas. Diffusion, why do you need to study
More informationRing current formation influenced by solar wind substorm conditions
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115,, doi:10.1029/2009ja014909, 2010 Ring current formation influenced by solar wind substorm conditions M. D. Cash, 1 R. M. Winglee, 1
More informationNonlinear stability of the near-earth plasma sheet during substorms
9 Nonlinear stability of the near-earth plasma sheet during substorms P. Dobias, J. A. Wanliss, and J. C. Samson 1. Introduction Abstract: We analyze a nonlinear stability of the near-earth plasma sheet
More informationPhysics For Scientists and Engineers A Strategic Approach 3 rd Edition, AP Edition, 2013 Knight
For Scientists and Engineers A Strategic Approach 3 rd Edition, AP Edition, 2013 Knight To the Advanced Placement Topics for C *Advanced Placement, Advanced Placement Program, AP, and Pre-AP are registered
More informationρ c (2.1) = 0 (2.3) B = 0. (2.4) E + B
Chapter 2 Basic Plasma Properties 2.1 First Principles 2.1.1 Maxwell s Equations In general magnetic and electric fields are determined by Maxwell s equations, corresponding boundary conditions and the
More informationMagnetism is associated with charges in motion (currents):
Electrics Electromagnetism Electromagnetism Magnetism is associated with charges in motion (currents): microscopic currents in the atoms of magnetic materials. macroscopic currents in the windings of an
More informationToroidal confinement devices
Toroidal confinement devices Dr Ben Dudson Department of Physics, University of York, Heslington, York YO10 5DD, UK 24 th January 2014 Dr Ben Dudson Magnetic Confinement Fusion (1 of 20) Last time... Power
More informationSpace Plasma Physics at the University of Minnesota
Space Plasma Physics at the University of Minnesota Faculty: Cindy Cattell, Bob Lysak, John Wygant, Paul Kellogg (emeritus) Research Scientists: Yan Song, John Dombeck Recent Graduates: Jim Crumley (St.
More informationTime Series of Images of the Auroral Substorm
ESS 7 Lecture 13 October 27, 2010 Substorms Time Series of Images of the Auroral Substorm This set of images in the ultra-violet from the Polar satellite shows changes that occur during an auroral substorm.
More informationA.G. PEETERS UNIVERSITY OF BAYREUTH
IN MEMORIAM GRIGORY PEREVERZEV A.G. PEETERS UNIVERSITY OF BAYREUTH ESF Workshop (Garching 2013) Research areas Grigory Pereverzev. Current drive in magnetized plasmas Transport (ASTRA transport code) Wave
More informationA Study of 3-Dimensional Plasma Configurations using the Two-Fluid Plasma Model
A Study of 3-Dimensional Plasma Configurations using the Two-Fluid Plasma Model B. Srinivasan, U. Shumlak Aerospace and Energetics Research Program University of Washington IEEE International Conference
More informationBasic plasma physics
Basic plasma physics SPAT PG Lectures Jonathan Eastwood 10-14 October 2016 Aims Provide new PhD students in SPAT and the SPC section with an overview of the most important principles in space plasma physics,
More informationVariations of Ion Drifts in the Ionosphere at Low- and Mid- Latitudes
Variations of Ion Drifts in the Ionosphere at Low- and Mid- Latitudes Edgardo E. Pacheco Jicamarca Radio Observatory Jul, 2014 Outline Motivation Introduction to Ionospheric Electrodynamics Objectives
More informationFundamentals of Plasma Physics
Fundamentals of Plasma Physics Definition of Plasma: A gas with an ionized fraction (n i + + e ). Depending on density, E and B fields, there can be many regimes. Collisions and the Mean Free Path (mfp)
More informationStability of the High-Latitude Reconnection Site for Steady. Lockheed Martin Advanced Technology Center, Palo Alto, CA
Page 1 Stability of the High-Latitude Reconnection Site for Steady Northward IMF S. A. Fuselier, S. M. Petrinec, K. J. Trattner Lockheed Martin Advanced Technology Center, Palo Alto, CA Abstract: The stability
More informationChapter 8 Geospace 1
Chapter 8 Geospace 1 Previously Sources of the Earth's magnetic field. 2 Content Basic concepts The Sun and solar wind Near-Earth space About other planets 3 Basic concepts 4 Plasma The molecules of an
More informationChapter 29. Magnetic Fields
Chapter 29 Magnetic Fields A Brief History of Magnetism 13 th century BC Chinese used a compass Uses a magnetic needle Probably an invention of Arabic or Indian origin 800 BC Greeks Discovered magnetite
More informationJOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. A10, 1283, doi: /2000ja000190, 2002
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. A10, 1283, doi:10.1029/2000ja000190, 2002 Dynamic fluid kinetic (DyFK) simulation of auroral ion transport: Synergistic effects of parallel potentials, transverse
More informationLecture 2. Introduction to plasma physics. Dr. Ashutosh Sharma
Preparation of the concerned sectors for educational and R&D activities related to the Hungarian ELI project Ion acceleration in plasmas Lecture 2. Introduction to plasma physics Dr. Ashutosh Sharma Zoltán
More informationMagnetospheric Currents at Quiet Times
Magnetospheric Currents at Quiet Times Robert L. McPherron Institute of Geophysics and Planetary Physics University of California Los Angeles Los Angeles, CA 90095-1567 e-mail: rmcpherron@igpp.ucla.edu
More informationCHARGED PARTICLE MOTION IN CONSTANT AND UNIFORM ELECTROMAGNETIC FIELDS
CHARGED PARTICLE MOTION IN CONSTANT AND UNIFORM ELECTROMAGNETIC FIELDS In this and in the following two chapters we investigate the motion of charged particles in the presence of electric and magnetic
More informationIntroduction to the Sun-Earth system Steve Milan
Introduction to the Sun-Earth system Steve Milan steve.milan@ion.le.ac.uk The solar-terrestrial system Corona is so hot that the Sun s gravity cannot hold it down it flows outwards as the solar wind A
More informationAPPENDIX Z. USEFUL FORMULAS 1. Appendix Z. Useful Formulas. DRAFT 13:41 June 30, 2006 c J.D Callen, Fundamentals of Plasma Physics
APPENDIX Z. USEFUL FORMULAS 1 Appendix Z Useful Formulas APPENDIX Z. USEFUL FORMULAS 2 Key Vector Relations A B = B A, A B = B A, A A = 0, A B C) = A B) C A B C) = B A C) C A B), bac-cab rule A B) C D)
More informationDescribe qualitatively some of the phenomena associated with currents and potential drops in the auroral zones.
Chapter 17 Auroral Physics As described in Lectures 14 to 16, Earth s auroral regions are coupled to the solar wind, magnetosphere, and ionosphere and are therefore the site of a number of space weather
More informationSimple examples of MHD equilibria
Department of Physics Seminar. grade: Nuclear engineering Simple examples of MHD equilibria Author: Ingrid Vavtar Mentor: prof. ddr. Tomaž Gyergyek Ljubljana, 017 Summary: In this seminar paper I will
More informationBasics of electromagnetic response of materials
Basics of electromagnetic response of materials Microscopic electric and magnetic field Let s point charge q moving with velocity v in fields e and b Force on q: F e F qeqvb F m Lorenz force Microscopic
More informationEvgeny Mishin. Physics of the Geospace Response to Powerful HF Radio Waves. Space Vehicles Directorate Air Force Research Laboratory
Physics of the Geospace Response to Powerful HF Radio Waves HAARP-Resonance Workshop, 8-9 November 2011 Evgeny Mishin Space Vehicles Directorate Air Force Research Laboratory Integrity Service Excellence
More informationEstimates of the Suprathermal O + outflow characteristic energy and relative location in the auroral oval
Estimates of the Suprathermal O + outflow characteristic energy and relative location in the auroral oval L. Andersson, W. K. Peterson and K. M. McBryde Laboratory for Atmospheric and Space Physics, University
More informationIntroduction to the Sun and the Sun-Earth System
Introduction to the Sun and the Sun-Earth System Robert Fear 1,2 R.C.Fear@soton.ac.uk 1 Space Environment Physics group University of Southampton 2 Radio & Space Plasma Physics group University of Leicester
More informationSub-Auroral Electric Fields: An Inner Magnetosphere Perspective
Sub-Auroral Electric Fields: An Inner Magnetosphere Perspective Bob Spiro Rice University 2005 GEM/CEDAR Tutorial 1 Introduction/Outline Introduction/Outline Importance of Sub-Auroral E-Fields Early Models
More informationProperties of Alfvén Waves in the Magnetotail Below 9 R E and Their Relation to Auroral Acceleration and Major Geomagnetic Storms
Properties of Alfvén Waves in the Magnetotail Below 9 R E and Their Relation to Auroral Acceleration and Major Geomagnetic Storms A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY
More informationThe Physics of Space Plasmas
The Physics of Space Plasmas Magnetic Storms, Substorms and the Generalized Ohm s Law William J. Burke 27 November 2012 University of Massachusetts, Lowell Lecture 10 Geomagnetic Storms: (continued ) Large
More informationA Correlation Study of Steady Magnetospheric Convection in the Northern and Southern Hemispheres
A Correlation Study of Steady Magnetospheric Convection in the Northern and Southern Hemispheres Caroline M. McElhenny 1, Dr. Anna DeJong 1 1 Christopher Newport University Abstract: The purpose of this
More informationMagnetostatics. P.Ravindran, PHY041: Electricity & Magnetism 22 January 2013: Magntostatics
Magnetostatics Magnetic Fields We saw last lecture that some substances, particularly iron, possess a property we call magnetism that exerts forces on other magnetic materials We also saw that t single
More informationHybrid magnetohydrodynamic-kinetic electron closure methods and shear Alfvén waves in nonuniform plasmas
PHYSICS OF PLASMAS 1, 04105 005 Hybrid magnetohydrodynamic-kinetic electron closure methods and shear Alfvén waves in nonuniform plasmas P. A. Damiano a and A. N. Wright Mathematical Institute, University
More informationr r 1 r r 1 2 = q 1 p = qd and it points from the negative charge to the positive charge.
MP204, Important Equations page 1 Below is a list of important equations that we meet in our study of Electromagnetism in the MP204 module. For your exam, you are expected to understand all of these, and
More informationPlasma pressure generated auroral current system: A case study
GEOPHYSICAL RESEARCH LETTERS, VOL. 39,, doi:10.1029/2012gl051211, 2012 Plasma pressure generated auroral current system: A case study S. B. Mende, 1 S. L. England, 1 and H. U. Frey 1 Received 2 February
More informationMagnetic Reconnection: explosions in space and astrophysical plasma. J. F. Drake University of Maryland
Magnetic Reconnection: explosions in space and astrophysical plasma J. F. Drake University of Maryland Magnetic Energy Dissipation in the Universe The conversion of magnetic energy to heat and high speed
More information