FUSION PHYSICS

By W. ELINM

CONTENTS CHAPTER THE CASE FOR FUSION 1 1 INTRODUCTION 1 2 ENERGY SCENARIOS 1 2 1 NEAR TERM ENERGY SCENARIO 1 2 2 LONG TERM ENERGY SCENARIO AND THE ROLE OF FUSION 1 3 FUSION BASICS 1 3 1 WHAT IS FUSION? 1 3 2 FUSION POWER GAIN Q 1 3 3 FUSION REACTIONS 1 3 4 FUSION FUELS 1 3 5 DIRECT CONVERSION TO ELECTRICITY 1 4 APPROACHES TO FUSION 1 4 1 MAGNETIC CONFINEMENT FUSION 1 4 1 1 PROGRESS IN TOKAMAK BASED MAGNETIC CONFINEMENT FUSION RESEARCH 1 4 2 INERTIAL CONFINEMENT FUSION 1 4 2 1 PROGRESS IN INERTIAL CONFINEMENT FUSION RESEARCH 1 5 SOCIOECONOMIC PERSPECTIVES 1 5 1 ENVIRONMENT, SAFETY AND NON-PROLIFERATION 1 5 1 1 EMISSIONS IN NORMAL OPERATION 1 5 1 2 POSSIBLE ACCIDENTS 1 5 1 3 WASTE 1 5 2 COST COMPARISON WITH OTHER SOURCES OF ENERGY 1 5 2 1 DIRECT COSTS OF FUSION POWER PRODUCTION 1 5 2 2 EXTERNAL COSTS OF FUSION POWER PRODUCTION 1 5 3 PUBLIC ACCEPTANCE OF FUSION 1 5 4 SPIN-OFFS OF FUSION RESEARCH 1 6 CONCLUSION CHAPTER PHYSICS OF CONFINEMENT 2 1 INTRODUCTION AND OVERVIEW 2 2 NEOCLASSICAL TRANSPORT 2 2 1 INTRODUCTION 2 2 2 TOROIDAL MAGNETIC CONFIGURATION 2 2 3 GUIDING CENTRE MOTION 2 2 4 THE DRIFT KINETIC EQUATION 2 2 5 BOOTSTRAP CURRENT 2 2 6 MAGNETIC FIELD RIPPLE 2 2 7 TRANSPORT IN A STOCHASTIC FIELD 2 3 TURBULENT TRANSPORT 2 3 1 INTRODUCTION 2 3 2 EXAMPLES OF BASIC MICROINSTABILITIES 2 3 2 1 ELECTRON DRIFT INSTABILITIES 2 3 2 2 ION TEMPERATURE GRADIENT INSTABILITIES 2 3 3 NON-LINEAR GYROKINETIC EQUATIONS FOR TOKAMAK TURBULENCE 2 3 4 KINETIC DESCRIPTION OF MICROINSTABILITIES 2 3 4 1 LINEAR ONSET CONDITION FOR ION TEMPERATURE GRADIENT MODE 2 3 4 2 ELECTRON TEMPERATURE GRADIENT INSTABILITY 2 3 4 3 TRAPPED PARTICLE INSTABILITIES 2 3 5 SPATIAL STRUCTURE OF MICROTURBULENCE 2 3 5 1 ROLE OF MAGNETIC SHEAR: SHEARED SLAB GEOMETRY 2 3 5 2 ROLE OF TOROIDAL GEOMETRY: BALLOONING REPRESENTATION 2 3 5 3 ROLE OF ZONAL FLOW SHEAR 2 3 6 DIFFERENT CHANNELS OF TURBULENCE TRANSPORT 2 3 6 1 ION THERMAL TRANSPORT 2 3 6 2 ELECTRON THERMAL TRANSPORT 2 3 6 3 PARTICLE TRANSPORT 2 3 6 4 MOMENTUM TRANSPORT 2 3 7 PHYSICS OF TRANSPORT BARRIERS 2 4 GLOBAL ENERGY CONFINEMENT SCALING STUDIES 2 4 1 INTRODUCTION 2 4 2 ENERGY CONFINEMENT SCALINGS: DIMENSIONAL PARAMETERS 2 4 2 1 OHMIC AND L-MODE PLASMA CONFINEMENT TRENDS 2 4 2 2 H-MODE CONFINEMENT TRENDS AND SCALINGS 2 4 2 3 ADVANCED STATISTICAL METHODS AND ERROR ANALYSIS 2 4 3 DIMENSIONLESS ANALYSIS 2 4 3 1 BASICS 2 4 3 2 SCALINGS 2 4 4 L-H THRESHOLD SCALINGS 2 4 5 IMPLICATIONS RELATIVE TO THEORETICAL MODELS 2 5 LOCAL TRANSPORT 2 5 1 BASICS 2 5 2 MODELS 2 5 2 1 NEUTRAL BEAM MODELS 2 5 2 2 NEUTRAL TRANSPORT 2 5 2 3 RF HEATING AND CURRENT DRIVE MODELS 2 5 2 4 CURRENT DRIVE MODELS 2 5 3 PERTURBATIVE TRANSPORT 2 5 4 PROFILE STIFFNESS 2 5 5 TRANSPORT BARRIERS 2 5 5 1 CORE 2 5 5 2 EDGE 2 5 6 COMPARISON WITH THEORETICAL MODELS 2 6 TURBULENCE MEASUREMENTS 2 6 1 MEASUREMENT TECHNIQUES 2 6 1 1 PROBE TECHNIQUES 2 6 1 2 ELECTROMAGNETIC WAVE SCATTERING 2 6 1 3 ELECTROMAGNETIC WAVE REFLECTOMETRY 2 6 1 4 ELECTROMAGNETIC WAVE DOPPLER BACKSCATTERING (DBS) 2 6 1 5 PHASE CONTRAST IMAGING (PCI) 2 6 1 6 HEAVY ION BEAM PROBE (HIBP) 2 6 1 7 BEAM EMISSION SPECTROSCOPY (BES) 2 6 1 8 HIGH FREQUENCY CHARGE EXCHANGE SPECTROSCOPY (HF CHERS) 2 6 1 9 CORRELATED ELECTRON CYCLOTRON EMISSION (CECE) 2 6 1 10 ANALYSIS TECHNIQUES 2 6 2 EXPERIMENTAL RESULTS 2 6 2 1 WAVENUMBER SPECTRA 2 6 2 2 FREQUENCY SPECTRA 2 6 2 3 RADIAL PROFILES 2 6 3 3 ION AND ELECTRON TEMPERATURE FLUCTUATIONS 2 6 3 4 ZONAL FLOWS AND GEODESIC ACOUSTIC MODES 2 6 3 5 CORE TURBULENCE SUPPRESSION 2 6 3 6 EVIDENCE FOR NON-LOCAL EFFECTS EQUILIBRIUM AND MACROSCOPIC STABILITY OF TOKAMAKS 3 1 INTRODUCTION 3 1 1 BASIC TOKAMAK CONFIGURATION 3 1 2 TIMESCALES OF TOKAMAK DYNAMICS 3 2 TOKAMAK EQUILIBRIUM 3 2 1 THE STRAIGHT CYLINDER 3 2 2 TOROIDAL PLASMA EQUILIBRIUM 3 2 2 1 THE LARGE ASPECT RATIO APPROXIMATION 3 2 2 2 FORMULATIONS OF THE GRAD–SHAFRANOV EQUATION 3 2 2 3 DIMENSIONLESS PARAMETERS CHARACTERIZING THE PLASMA EQUILIBRIUM 3 2 2 4 SHAPING OF PLASMA CROSS-SECTION AND THE TOKAMAK POLOIDAL FIELD SYSTEM 3 2 2 5 AXISYMMETRIC STABILITY OF TOKAMAK EQUILIBRIA 3 3 THEORY OF MACROSCOPIC INSTABILITIES IN TOKAMAKS 3 3 1 ONE-FLUID MHD STABILITY THEORY 3 3 1 1 IDEAL MHD STABILITY 3 3 1 2 EFFECTS OF DISSIPATION ON LINEAR STABILITY OF GLOBAL MODES 3 3 1 3 FINITE AMPLITUDE PERTURBATIONS 3 3 2 EXTENSIONS TO THE MHD MODEL 3 3 2 1 INTRODUCTION 3 3 2 2 DERIVATION EXAMPLE: REDUCED (LOW FREQUENCY) MHD 3 3 2 3 DERIVATION EXAMPLE: TWO-FLUID EQUATIONS 3 3 2 4 RELATION TO KINETIC MODELS 3 3 2 5 QUALITATIVE TWO-FLUID EFFECTS ON MHD INSTABILITIES 3 3 3 ENERGETIC PARTICLE PHYSICS AND KINETIC MHD 3 3 3 1 INTRODUCTION 3 3 3 2 MODELS 3 3 3 3 GLOBAL MODES IN TOROIDAL GEOMETRY 3 4 EXPERIMENTAL OBSERVATIONS OF MHD MODES 3 4 1 INTERNAL KINK MODES 3 4 2 CLASSICAL TEARING MODES 3 4 3 NEOCLASSICAL TEARING MODES (NTMS) 3 4 4 EDGE LOCALIZED MODES (ELMS) 3 4 5 IDEAL PRESSURE LIMITING MODES 3 4 6 WALL EFFECTS ON MHD MODES 3 4 7 ALFVÉN AND ENERGETIC PARTICLE MODES (EPMS) 3 5 DISRUPTIVE INSTABILITIES 3 5 1 INTRODUCTION 3 5 2 CLASSIFICATION BY CAUSES 3 5 2 1 DENSITY LIMIT DISRUPTIONS 3 5 2 2 BETA LIMIT 3 5 2 3 LIMIT ON Q 3 5 3 PHASES OF DISRUPTIONS 3 5 3 1 THERMAL QUENCH 3 5 3 2 CURRENT QUENCH 3 5 4 DAMAGE POTENTIAL 3 5 4 1 HEAT PULSE 3 5 4 2 ELECTROMAGNETIC FORCES 3 5 4 3 RUNAWAY GENERATION 3 5 5 MITIGATION METHODS PLASMA DIAGNOSTICS 4 1 INTRODUCTION 4 2 PASSIVE DIAGNOSTIC METHODS 4 2 1 MAGNETIC MEASUREMENTS 4 2 2 ELECTRICAL PROBES (LANGMUIR PROBES) 4 2 2 1 INTRODUCTION TO ELECTRICAL PROBES 4 2 2 2 LANGMUIR PROBES 4 2 3 VISIBLE AND UV SPECTROSCOPY 4 2 4 BOLOMETRY 4 2 4 1 THERMAL DEVICES 4 2 4 2 AXUV DETECTORS 4 2 5 METHODS BASED ON ELECTRON CYCLOTRON EMISSION MEASUREMENTS 4 2 6 PASSIVE NEUTRAL PARTICLE ANALYSIS 4 2 7 METHODS BASED ON X RAY RADIATION 4 2 7 1 SOFT X RAY RADIATION 4 2 7 2 HIGH RESOLUTION X RAY SPECTROSCOPY 4 2 8 EXPERIMENTAL NUCLEAR PHYSICS METHODS 4 2 8 1 NEUTRONS, CHARGED FUSION PRODUCTS, HARD X RAYS 4 2 8 2 GAMMA RAY SPECTROMETRY 4 3 ACTIVE DIAGNOSTIC METHODS 4 3 1 PROBING BY LASER BEAMS 4 3 1 1 THOMSON SCATTERING 4 3 1 2 LASER INDUCED FLUORESCENCE TECHNIQUE 4 3 2 PROBING BY PARTICLES 4 3 2 1 DIAGNOSTIC NEUTRAL BEAMS FOR PLASMA STUDIES IN MAGNETIC FUSION DEVICES 4 3 2 2 ACTIVE CHARGE EXCHANGE RECOMBINATION SPECTROSCOPY DIAGNOSTIC 4 3 2 3 MOTIONAL STARK EFFECT 4 3 2 4 ACTIVE CHARGE EXCHANGE AND RUTHERFORD SCATTERING 4 3 2 5 HEAVY ION BEAM PROBE DIAGNOSTICS 4 3 3 PROBING BY MICROWAVES AND LASER BEAM: INTERFEROMETRY, POLARIMETRY, REFLECTOMETRY 4 3 3 1 INTRODUCTION 4 3 3 2 INTERFEROMETRY AND POLARIMETRY 4 3 3 3 PLASMA REFLECTOMETRY FOR ELECTRON CONCENTRATION PROFILE MEASUREMENTS 4 3 3 4 APPLICATION OF REFLECTOMETRY TO DENSITY FLUCTUATION MEASUREMENTS 4 4 ENGINEERING PROBLEMS 4 4 1 CHANGING OF MECHANICAL PROPERTIES 4 4 2 CHANGING IN ELECTRICAL PROPERTIES 4 4 3 CHANGES IN OPTICAL PROPERTIES 4 5 CONCLUSION PLASMA HEATING AND CURRENT DRIVE BY NEUTRAL BEAM AND ?LPHA PARTICLES 5 1 HEATING AND CURRENT DRIVE PHYSICS BY NEUTRAL BEAM AND ALPHA PARTICLES 5 1 1 BASIC PROCESSES OF NEUTRAL BEAM INJECTION 5 1 2 PHYSICS OF IONIZATION OF INJECTED NEUTRAL BEAM 5 1 3 MULTI-STEP IONIZATION AND LORENZ IONIZATION 5 1 4 ENERGY TRANSFER TO ELECTRONS AND IONS BY NEUTRAL BEAM INJECTION 5 1 5 ENERGETIC PARTICLE ORBITS ON THE AXISYMMETRIC MAGNETIC SURFACES 5 1 6 FAST ION BEHAVIOUR AND HIGH TEMPERATURE PRODUCTION WITH NB INJECTION 5 1 7 PHYSICS OF NEUTRAL BEAM CURRENT DRIVE: FAST ION DISTRIBUTION FUNCTION 5 1 7 1 RAYLEIGH–RITZ METHOD 5 1 8 PHYSICS OF NEUTRAL BEAM CURRENT DRIVE: SHIELDING CURRENT AND NBCD EFFICIENCY 5 1 9 EXPERIMENTAL OBSERVATION OF BEAM-DRIVEN CURRENT 5 1 10 PHYSICS OF RIPPLE LOSS OF FAST IONS: BANANA DRIFT AND RIPPLE TRAPPED LOSSES 5 1 11 PHYSICS OF PARTICLE TRAJECTORIES IN NON-AXISYMMETRIC FIELDS 5 1 12 ALPHA HEATING 5 1 13 D-T EXPERIMENTS IN LARGE TOKAMAKS (TFTR AND JET) 5 2 NEUTRAL BEAM HEATING 5 2 1 INTRODUCTION 5 2 2 ION SOURCE 5 2 2 1 PLASMA GENERATOR 5 2 2 2 MULTICUSP SOURCE 5 2 2 3 RADIOFREQUENCY PLASMA SOURCE 5 2 3 EXTRACTION AND ACCELERATION 5 2 3 1 CHILD–LANGMUIR LAW 5 2 3 2 MULTI-STAGE ACCELERATION 5 2 3 3 BEAMLET STEERING 5 2 4 POSITIVE-ION-BASED NBI 5 2 5 NEGATIVE ION SOURCE 5 2 5 1 NEGATIVE ION PRODUCTION 5 2 5 2 ADVANTAGES OF VOLUME PRODUCTION 5 2 5 3 CAESIUM SEEDING 5 2 6 NEGATIVE ION EXTRACTION/ACCELERATION 5 2 7 NEGATIVE-ION-BASED NBI 5 2 7 1 N-NBI FOR JT-60 5 2 7 2 N-NBI FOR LHD 5 2 7 3 N-NBI FOR ITER 5 2 8 MV POWER SUPPLY 5 2 9 REMARKS ON FUTURE NBI TECHNOLOGY RADIOFREQUENCY WAVES, HEATING AND CURRENT DRIVE IN MAGNETICALLY CONFINED PLASMAS 6 1 INTRODUCTION 6 2 THEORY OF RF WAVE PROPAGATION IN A MAGNETIZED PLASMA 6 2 1 ELECTRON CYCLOTRON WAVES 6 2 2 LOWER HYBRID WAVE PROPAGATION AND ACCESSIBILITY 6 2 3 ION CYCLOTRON WAVE PROPAGATION AND ACCESSIBILITY 6 2 4 ICRF WAVE ABSORPTION IN A HOT PLASMA 6 2 4 1 ABSORPTION ON ELECTRONS 6 2 4 2 ABSORPTION OF ICRF WAVES ON ION CYCLOTRON HARMONICS 6 2 4 3 MINORITY ION CYCLOTRON ABSORPTION 6 2 5 QUASI-LINEAR ABSORPTION OF ICRF WAVES ON IONS 6 2 6 QUASI-LINEAR ABSORPTION ON ELECTRONS 6 2 6 1 LOWER HYBRID CURRENT DRIVE 6 2 6 2 ELECTRON CYCLOTRON CURRENT DRIVE 6 2 6 3 CURRENT DRIVE BY THE FAST ICRF WAVES 6 2 7 WAVE PROPAGATION IN TOROIDAL GEOMETRY, GEOMETRIC OPTICS 6 2 7 1 GEOMETRIC OPTICS AND THE RAY EQUATIONS 6 2 7 2 MODIFICATIONS TO WAVE ACCESSIBILITY AND ABSORPTION IN TOROIDAL GEOMETRY 6 2 7 3 NUMERICAL SIMULATIONS OF LOWER HYBRID CURRENT DRIVE USING COUPLED FOKKER–PLANCK AND RAY TRACING CALCULATIONS 6 2 8 WAVE PROPAGATION IN TOROIDAL GEOMETRY, FULL-WAVE TREATMENT 6 2 8 1 FULL-WAVE SIMULATIONS OF MINORITY HEATING IN THE ICRF 6 2 8 2 FULL-WAVE SIMULATIONS OF MODE CONVERSION IN THE ICRF 6 2 8 3 FULL-WAVE SIMULATIONS OF LOWER HYBRID WAVES 6 3 EXPERIMENTAL RESULTS ON RF HEATING AND CURRENT DRIVE 6 3 1 ICRF HEATING AND CURRENT DRIVE EXPERIMENTS 6 3 2 ICRF ANTENNA AND TRANSMISSION LINE DESIGN 6 3 2 1 ICRF TRANSMISSION LINE ARCHITECTURE 6 3 2 2 ICRF SOURCE TECHNOLOGY 6 3 2 3 ICRF TRANSMISSION LINE DESIGN 6 3 2 4 ICRF WAVE LAUNCHERS 6 3 3 LOWER HYBRID HEATING AND CURRENT DRIVE EXPERIMENTS 6 3 4 LOWER HYBRID WAVE LAUNCHERS 6 3 4 1 RF COUPLING THEORY 6 3 4 2 NUMERICAL COUPLING CODES 6 3 4 3 EVOLUTION OF LH LAUNCHERS IN TOKAMAKS 6 3 5 APPLICATIONS OF ELECTRON CYCLOTRON HEATING AND CURRENT DRIVE 6 3 5 1 WAVE PROPAGATION AND ABSORPTION EXPERIMENTS 6 3 5 2 ELECTRON CYCLOTRON CURRENT DRIVE (ECCD) EXPERIMENTS 6 3 6 ELECTRON CYCLOTRON TRANSMISSION LINE AND ANTENNA DESIGN 6 4 GYROTRONS FOR ECR HEATING AND CURRENT DRIVE 6 4 1 INTRODUCTION TO GYROTRONS 6 4 2 PHYSICAL PRINCIPLES OF THE GYROTRON 6 4 3 OVERVIEW OF GYROTRON THEORY 6 4 4 ENGINEERING FEATURES OF THE GYROTRON 6 4 4 1 ELECTRON GUN AND BEAM TUNNEL 6 4 4 2 GYROTRON CAVITY 6 4 4 3 INTERNAL MODE CONVERTER (IMC) 6 4 4 4 PHASE CORRECTING MIRRORS AND OUTPUT WINDOW 6 4 4 5 DEPRESSED COLLECTOR 6 4 4 6 AUXILIARY COMPONENTS 6 4 5 STATE OF THE ART GYROTRONS 6 4 6 PROSPECTS AND FUTURE DIRECTIONS 6 4 6 1 MULTI-MEGAWATT GYROTRONS 6 4 6 2 FREQUENCY TUNEABLE GYROTRONS 6 4 6 3 IMPROVEMENT OF GYROTRON EFFICIENCY 6 4 6 4 GYROTRONS FOR DEMO PLASMA–WALL INTERACTIONS 7 1 INTRODUCTION 7 2 BASIC PHYSICAL PROCESSES AND UNDERLYING THEORY 7 2 1 BASIC CONCEPTS 7 2 1 1 BOUNDARY LAYER 7 2 1 2 THE PLASMA SHEATH 7 2 1 3 THE SCRAPE-OFF LAYER 7 2 2 RECYCLING 7 2 3 ATOMIC AND MOLECULAR PROCESSES 7 2 4 EROSION PROCESSES 7 2 4 1 PHYSICAL SPUTTERING 7 2 4 2 CHEMICAL SPUTTERING 7 2 4 3 ARCING 7 3 DEVELOPMENT OF PLASMA FACING MATERIALS 7 3 1 CARBON CONTAINING MATERIALS 7 3 2 BERYLLIUM 7 3 3 HIGH-Z MATERIALS 7 3 4 MIXED MATERIALS 7 4 PRESENT PROGRESS OF PLASMA–WALL INTERACTIONS IN TOKAMAKS 7 4 1 WALL CONDITIONING 7 4 1 1 SURFACE CLEANING 7 4 1 2 PLASMA ASSISTED COATING OF THIN FILMS 7 4 2 IMPURITIES AND DUSTS 7 4 2 1 IMPURITIES 7 4 2 2 DUSTS 7 4 3 EROSION AND RE-DEPOSITION 7 4 3 1 DIVERTOR EROSION AND RE-DEPOSITION 7 4 3 2 LIMITER EROSION AND RE-DEPOSITION 7 4 3 3 MAIN CHAMBER WALL EROSION AND RE-DEPOSITION 7 4 4 HYDOGEN ISOTOPE RETENTION AND REMOVAL 7 5 CONTROL OF PLASMA–WALL INTERACTIONS 7 5 1 DIVERTORS 7 5 1 1 INTRODUCTION 7 5 1 2 DIVERTOR OPERATION REGIMES 7 5 1 3 EFFECT OF DIVERTOR GEOMETRY 7 5 2 PARTICLE TRANSPORT IN THE DIVERTOR SOL 7 5 2 1 PLASMA FLOW AND DRIFT EFFECTS 7 5 2 2 RECENT ADVANCES ON CROSS-FIELD PARTICLE TRANSPORT 7 5 3 ENERGY DEPOSITION 7 5 3 1 STEADY STATE POWER LOAD ON THE DIVERTOR 7 5 3 2 TRANSIENT ENERGY DEPOSITION DURING ELMS 7 5 3 3 ACTIVE CONTROL OF PEAK HEAT FLUXES 7 6 ISSUES OF PLASMA–WALL INTERACTIONS FOR NEXT STEP TOKAMAKS 7 6 1 POWER HANDLING AND PARTICLE EXHAUST 7 6 2 TRANSIENT HEAT LOADS 7 6 3 MATERIAL MIGRATION 7 6 4 CONTROL OF IN-VESSEL TRITIUM INVENTORY 7 6 5 INTEGRATED PWI ISSUES FOR STEADY STATE OPERATION HELICAL CONFINEMENT CONCEPTS 8 1 INTRODUCTION 8 2 HELICAL CONFINEMENT CONCEPTS 8 2 1 PRODUCTION OF 3-D TOROIDAL FLUX SURFACES 8 2 2 HELICAL CONFINEMENT DEVICES 8 2 2 1 CLASSICAL STELLARATORS 8 2 2 2 TORSATRONS/HELIOTRONS 8 2 2 3 HELIACS 8 2 2 4 MODULAR STELLARATORS 8 3 THE PHYSICS OF HELICAL SYSTEMS 8 3 1 HEATING AND PARTICLE–WAVE INTERACTION 8 3 1 1 ELECTRON CYCLOTRON HEATING AND CURRENT DRIVE 8 3 1 2 ELECTRON BERNSTEIN WAVE HEATING IN STELLARATORS 8 3 1 3 ION CYCLOTRON HEATING IN HELICAL SYSTEMS 8 3 2 PLASMA EQUILIBRIUM 8 3 2 1 BASIC EQUILIBRIUM PROPERTIES 8 3 2 2 OPTIMIZED STELLARATORS 8 3 2 3 COMPUTATION OF 3-D EQUILIBRIA 8 3 2 4 EXPERIMENTAL EQUILIBRIUM IDENTIFICATION 8 3 3 PLASMA STABILITY 8 3 3 1 INTRODUCTION AND THEORETICAL BACKGROUND 8 3 3 2 BALLOONING MODES 8 3 3 3 GLOBAL PRESSURE DRIVEN MODES 8 3 3 4 ENERGETIC PARTICLE DRIVEN ALFVÉN INSTABILITIES 8 3 4 BOUNCE-AVERAGED PARTICLE ORBITS 8 3 5 NEOCLASSICAL TRANSPORT MODELS 8 3 5 1 NEOCLASSICAL MODELLING 8 3 5 2 CLASSICAL AND ADVANCED STELLARATOR CONFIGURATIONS 8 3 5 3 RADIAL ELECTRIC FIELD 8 3 5 4 BOOTSTRAP CURRENT 8 3 5 5 PARALLEL RESISTIVITY 8 3 5 6 OPTIMIZATION OF NEOCLASSICAL TRANSPORT 8 3 6 3-D FEATURES OF TRANSPORT AND CONFINEMENT 8 3 6 1 ROLE OF NEOCLASSICAL TRANSPORT 8 3 6 2 CHARACTERIZATION OF TURBULENT TRANSPORT 8 3 6 3 PARTICLE TRANSPORT 8 3 6 4 ELECTRON TEMPERATURE EVOLUTION 8 3 6 5 ISOTOPIC EFFECT 8 3 6 6 MAGNETIC CONFIGURATION EFFECTS ON CONFINEMENT 8 3 6 7 IMPROVED CONFINEMENT REGIMES 8 3 6 8 IMPURITY TRANSPORT 8 3 7 BOUNDARY LAYER AND DIVERTOR PHYSICS 8 3 7 1 ISLAND DIVERTOR CONCEPTS 8 3 7 2 TRANSPORT FEATURES OF HELICAL SOLS 8 3 7 3 DETACHMENT REGIME 8 4 OPERATIONAL LIMITS 8 4 1 DENSITY LIMIT 8 4 2 BETA LIMIT 8 5 STELLARATOR OPTIMIZATION 8 5 1 EQUILIBRIUM 8 5 2 PARTICLE DRIFT 8 5 3 STABILITY 8 5 4 INTEGRATED OPTIMIZATION CONCEPTS 8 6 HELICAL REACTOR CONCEPTS 8 6 1 HELIOTRON REACTORS 8 6 2 MODULAR STELLARATOR REACTORS 8 6 2 1 US COMPACT STELLARATOR POWER PLANT STUDY (SPPS) 8 6 2 2 THE HELIAS REACTOR 8 6 3 CONCLUDING REMARKS THE BROADER SPECTRUM OF MAGNETIC CONFIGURATIONS FOR FUSION 9 1 INTRODUCTION 9 2 REVERSED FIELD PINCH: TOROIDAL CONFINEMENT AT WEAK MAGNETIC FIELD 9 2 1 THE CONFIGURATION: IDEAL MHD EQUILIBRIUM AND STABILITY 9 2 1 1 CURRENT DRIVEN INSTABILITY 9 2 1 2 PRESSURE DRIVEN INSTABILITY 9 2 2 REVERSAL OF MAGNETIC FIELD: MINIMUM ENERGY STATE AND RECONNECTION 9 2 2 1 MINIMUM ENERGY STATE 9 2 2 2 STANDARD MODEL OF RFP DYNAMICS: NON-LINEAR TEARING MODES AND MAGNETIC RECONNECTION 9 2 3 CONFINEMENT: EFFECTS OF MAGNETIC STOCHASTICITY 9 2 4 IMPROVED CONFINEMENT 9 2 4 1 ELIMINATING THE FREE ENERGY SOURCE 9 2 4 2 SINGLE HELICITY STATES 9 2 5 BETA LIMITS IN THE RFP 9 2 6 RESISTIVE WALL INSTABILITIES AND THEIR CONTROL 9 2 6 1 CHARACTERISTICS OF RESISTIVE WALL INSTABILITIES IN THE RFP 9 2 6 2 FEEDBACK SUPPRESSION OF RESISTIVE WALL INSTABILITIES 9 2 7 SUSTAINING THE PLASMA 9 3 COMPACT TORI: ELIMINATING THE HOLE IN THE TORUS 9 3 1 SPHEROMAKS 9 3 1 1 MAGNETIC SURFACES 9 3 1 2 SPHEROMAK FORMATION 9 3 1 3 SUSTAINMENT PHASE AND HELICITY INJECTION 9 3 1 4 CURRENT AMPLIFICATION 9 3 1 5 REGULAR VERSUS STOCHASTIC MAGNETIC FIELD 9 3 1 6 SPHEROMAK: A FLEXIBLE CONFIGURATION 9 3 2 FIELD REVERSED CONFIGURATION (FRC) 9 3 2 1 FIELD GEOMETRY 9 3 2 2 FRC FORMATION 9 3 2 3 FRC EQUILIBRIUM 9 3 2 4 PLASMA ROTATION AND STABILITY 9 3 2 5 STEADY STATE FRCS 9 4 OPEN CONFINEMENT SYSTEMS 9 4 1 CONFINING A PLASMA ON THE OPEN FIELD LINES 9 4 2 MIRROR CONFINEMENT 9 4 3 ROLE OF ION COLLISIONS 9 4 4 ELECTRON AXIAL CONFINEMENT 9 4 5 VELOCITY-SPACE MICROINSTABILITIES 9 4 6 MHD STABILITY 9 4 7 SUPPRESSION OF END LOSSES 9 4 7 1 TANDEM MIRRORS 9 4 7 2 PLASMA ROTATION 9 4 7 3 GAS-DYNAMIC TRAP 9 5 OTHER FUSION CONFIGURATIONS: A BROAD RANGE OF IDEAS 9 5 1 LEVITATED DIPOLES 9 5 2 CUSPS 9 5 3 MAGNETO-ELECTROSTATIC CONFINEMENT AND ELECTROSTATIC CONFINEMENT 9 5 4 PINCHES 9 5 5 MAGNETIZED TARGET FUSION 9 5 6 OTHER CONCEPTS 9 6 SUMMARY INERTIAL FUSION ENERGY 10 1 BRIEF HISTORY 10 2 INTRODUCTION 10 3 BASIC CONCEPT OF INERTIAL FUSION ENERGY 10 4 REQUIREMENT ON FUSION GAIN 10 5 IMPLOSION CONCEPT 10 5 1 WHY COMPRESSION? 10 5 2 GAIN SCALING OF IMPLOSION IGNITION 10 6 IMPLOSION PHYSICS 10 6 1 ABLATIVE ACCELERATION AND LASER–THROUGHOUT PLASMA INTERACTION IN DIRECT DRIVE IMPLOSION 10 6 2 CLASSICAL ABSORPTION 10 6 3 COLLECTIVE LASER PLASMA INTERACTIONS 10 6 3 1 RESONANT MODE CONVERSION 10 6 3 2 DENSITY PROFILE MODIFICATIONS 10 6 3 3 ELECTRON–ION DECAY AND OSCILLATING TWO STREAM INSTABILITIES 10 6 3 4 TWO-PLASMON DECAY INSTABILITY 10 6 3 5 STIMULATED RAMAN SCATTERING 10 6 3 6 STIMULATED BRILLOUIN SCATTERING 10 6 3 7 FILAMENTATION INSTABILITY: SELF-FOCUSING 10 7 ABLATION PRESSURE AND DIRECT DRIVE IMPLOSION HYDRODYNAMICS 10 7 1 ABLATION PRESSURE 10 7 2 ROCKET MODEL AND HYDRODYNAMIC EFFICIENCY 10 7 3 IMPLOSION NON-UNIFORMITY AND STABILITY 10 7 4 IMPLOSION INSTABILITIES 10 8 FAST IGNITION: PRESENT STATUS AND FUTURE PROSPECTS 10 8 1 WHY FAST IGNITION? 10 8 2 IGNITION CONDITIONS 10 8 3 FAST IGNITION INTEGRATED EXPERIMENTS 10 8 3 1 DIRECT PLASMA HEATING 10 8 3 2 CONE-SHELL TARGET 10 8 4 FAST IGNITION SIMULATION 10 8 4 1 INTEGRATED SIMULATION 10 8 4 2 RADIATION HYDRODYNAMIC SIMULATION 10 8 5 RELATIVISTIC ELECTRON GENERATION, TRANSPORT AND HEATING PHYSICS 10 8 6 PETAWATT LASER AND FUTURE FAST IGNITION FACILITY 10 9 INDIRECT DRIVE FUSION 10 9 1 CONCEPT OF INDIRECT DRIVE IMPLOSION 10 9 2 STATUS OF INDIRECT DRIVE IMPLOSION EXPERIMENTS 10 9 3 RECENT PROGRESS IN INDIRECT DRIVE EXPERIMENTS 10 9 4 OTHER DRIVERS FOR INDIRECT DRIVE IMPLOSION 10 10 IFE POWER PLANT DEVELOPMENT 10 10 1 IFE POWER PLANT SYSTEMS 10 10 2 DRIVER DEVELOPMENT 10 10 3 REACTION CHAMBER 10 10 4 FUEL PELLET 10 10 5 RECENT PROGRESS IN INERTIAL FUSION TECHNOLOGIES 10 10 5 1 LIFE PROJECT AT LLNL 10 10 5 2 HIPER PROJECT IN THE EU 10 10 5 3 RECENT PROGRESS IN LASER TECHNOLOGY 10 10 5 4 RECENT PROGRESS OF TARGET FABRICATION AND INJECTION TECHNOLOGY THE CASE FOR FUSION P K KAW, I BANDYOPADHYAY INSTITUTE FOR PLASMA RESEARCH, BHAT, GANDHINAGAR, GUJARAT, INDIA 1 1 INTRODUCTION HUMANS DO NOT LIVE BY BREAD ALONE PHYSICALLY WE ARE PUNY CREATURES WITH LIMITED PROWESS, BUT WITH UNLIMITED DREAMS WE SEE A MOUNTAIN AND WANT TO MOVE IT TO CARVE OUT A PATH FOR OURSELVES WE SEE A RIVER AND WANT TO TAME IT SO THAT IT IRRIGATES OUR FIELDS WE SEE A STAR AND WANT TO FLY TO ITS PLANETS TO SECURE A FUTURE FOR OUR PROGENY FOR ALL THIS, WE NEED A GENIE WHO WILL DO OUR BIDDING AT A FLIP OF OUR FINGERS ENERGY IS SUCH A GENIE MODERN HUMANS NEED ENERGY AND LOTS OF IT TO LIVE A LIFE OF COMFORT IN FACT, THE QUALITY OF LIFE IN DIFFERENT REGIONS OF THE WORLD CAN BE DIRECTLY CORRELATED WITH THE PER CAPITA USE OF ENERGY [1 1–1 5] IN THIS REGARD, THE HUMAN DEVELOPMENT INDEX (HDI) OF VARIOUS COUNTRIES BASED ON VARIOUS REPORTS BY THE UNITED NATIONS DEVELOPMENT PROGRAMME (UNDP) [1 6] (FIG 1 1), WHICH IS A PARAMETER MEASURING THE QUALITY OF LIFE IN A GIVEN PART OF THE WORLD, IS DIRECTLY DETERMINED BY THE AMOUNT OF PER CAPITA ELECTRICITY CONSUMPTION MOST OF THE DEVELOPING WORLD (~5 BILLION PEOPLE) IS CRAWLING UP THE UN CURVE OF HDI VERSUS PER CAPITA ELECTRICITY CONSUMPTION, FROM ABYSMALLY LOW VALUES OF TODAY TOWARDS THE AVERAGE OF THE WHOLE WORLD AND EVENTUALLY TOWARDS THE AVERAGE OF THE DEVELOPED WORLD THIS TRANSLATES INTO A MASSIVE ENERGY HUNGER FOR THE GLOBE AS A WHOLE IT HAS BEEN ESTIMATED THAT BY THE YEAR 2050, THE GLOBAL ELECTRICITY DEMAND WILL GO UP BY A FACTOR OF UP TO 3 IN A HIGH GROWTH SCENARIO [1 7–1 9] THE REQUIREMENTS BEYOND 2050 GO UP EVEN HIGHER HOW IS HUMANKIND GOING TO PRODUCE THE VAST AMOUNT OF ENERGY IT NEEDS? IN THE ABSENCE OF ANY NEW DEVELOPMENTS, THE WORKHORSE IS LIKELY TO BE BASED ON FOSSIL FUELS ON THE OTHER HAND, THE USE OF FOSSIL FUELS AS THE MAJOR SOURCE OF ENERGY OVER THE LAST CENTURY HAS LED TO SIGNIFICANT GLOBAL WARMING THROUGH THE EMISSION OF GREENHOUSE GASES ALSO, THE FOSSIL FUEL RESERVES HAVE STARTED DEPLETING WITH ONLY COAL, THE LARGEST EMITTER OF CO2, HAVING THE POTENTIAL TO LAST A FEW HUNDRED YEARS OIL AND GAS RESERVES HAVE ALREADY STARTED DWINDLING AND WOULD LAST A FEW TENS OF YEARS BY VARIOUS ESTIMATES; POLITICAL AND MILITARY CONFLICTS FOR CONTROL OF OIL AND GAS HAVE ALREADY DOMINATED THE WORLD ENERGY SCENARIO OVER THE LAST DECADE DEPLOYMENT OF CONVENTIONAL FISSION BASED NUCLEAR POWER, ON THE OTHER HAND, HAS FACED SERIOUS PUBLIC OPPOSITION DUE TO CONCERNS OF PROLIFERATION, RADIOACTIVE HAZARDOUS WASTES, THE POTENTIAL FOR CATASTROPHIC CHERNOBYL LIKE DISASTERS, ETC , ALL