Introduction to plasma physics and controlled fusion azw3 网盘 高速 下载地址大全 免费

This complete introduction to plasma physics and controlled fusion by one of the pioneering scientists in this expanding field offers both a simple and intuitive discussion of the basic concepts of this subject and an insight into the challenging problems of current research. In a wholly lucid manner the work covers single-particle motions, fluid equations for plasmas, wave motions, diffusion and resistivity, Landau damping, plasma instabilities and nonlinear problems. For students, this outstanding text offers a painless introduction to this important field; for teachers, a large collection of problems; and for researchers, a concise review of the fundamentals as well as original treatments of a number of topics never before explained so clearly. This revised edition contains new material on kinetic effects, including Bernstein waves and the plasma dispersion function, and on nonlinear wave equations and solitons. For the third edition, updates was made throughout each existing chapter, and two new chapters were added; Ch 9 on “Special Plasmas” and Ch 10 on Plasma Applications (including Atmospheric Plasmas).

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Occurrence of Plasmas in Nature . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Definition of Plasma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Concept of Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.4 Debye Shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.5 The Plasma Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.6 Criteria for Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.7 Applications of Plasma Physics . . . . . . . . . . . . . . . . . . . . . . . . 12 1.7.1 Gas Discharges (Gaseous Electronics) . . . . . . . . . . . . . 13 1.7.2 Controlled Thermonuclear Fusion . . . . . . . . . . . . . . . . 13 1.7.3 Space Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 1.7.4 Modern Astrophysics . . . . . . . . . . . . . . . . . . . . . . . . . 14 1.7.5 MHD Energy Conversion and Ion Propulsion . . . . . . . 15 1.7.6 Solid State Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.7.7 Gas Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.7.8 Particle Accelerators . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.7.9 Industrial Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.7.10 Atmospheric Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . 17 2 Single-Particle Motions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2 Uniform E and B Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.1 E ¼ 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.2 Finite E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.2.3 Gravitational Field . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2.3 Nonuniform B Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.3.1 ∇B⊥B: Grad-B Drift . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.3.2 Curved B: Curvature Drift . . . . . . . . . . . . . . . . . . . . . 28 2.3.3 ∇BjjB: Magnetic Mirrors . . . . . . . . . . . . . . . . . . . . . . 29 vii2.4 Nonuniform E Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.5 Time-Varying E Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2.6 Time-Varying B Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 2.7 Summary of Guiding Center Drifts . . . . . . . . . . . . . . . . . . . . . 41 2.8 Adiabatic Invariants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2.8.1 The First Adiabatic Invariant, μ . . . . . . . . . . . . . . . . . 42 2.8.2 The Second Adiabatic Invariant, J . . . . . . . . . . . . . . . 44 2.8.3 The Third Adiabatic Invariant, Ф . . . . . . . . . . . . . . . . 47 3 Plasmas as Fluids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.2 Relation of Plasma Physics to Ordinary Electromagnetics . . . . . 52 3.2.1 Maxwell’s Equations . . . . . . . . . . . . . . . . . . . . . . . . . 52 3.2.2 Classical Treatment of Magnetic Materials . . . . . . . . . 53 3.2.3 Classical Treatment of Dielectrics . . . . . . . . . . . . . . . . 54 3.2.4 The Dielectric Constant of a Plasma . . . . . . . . . . . . . . 55 3.3 The Fluid Equation of Motion . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.3.1 The Convective Derivative . . . . . . . . . . . . . . . . . . . . . 56 3.3.2 The Stress Tensor . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 3.3.3 Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 3.3.4 Comparison with Ordinary Hydrodynamics . . . . . . . . . 63 3.3.5 Equation of Continuity . . . . . . . . . . . . . . . . . . . . . . . . 64 3.3.6 Equation of State . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 3.3.7 The Complete Set of Fluid Equations . . . . . . . . . . . . . 65 3.4 Fluid Drifts Perpendicular to B . . . . . . . . . . . . . . . . . . . . . . . . 65 3.5 Fluid Drifts Parallel to B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 3.6 The Plasma Approximation . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 4 Waves in Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 4.1 Representation of Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 4.2 Group Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 4.3 Plasma Oscillations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 4.4 Electron Plasma Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 4.5 Sound Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 4.6 Ion Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 4.7 Validity of the Plasma Approximation . . . . . . . . . . . . . . . . . . . 92 4.8 Comparison of Ion and Electron Waves . . . . . . . . . . . . . . . . . . 93 4.9 Electrostatic Electron Oscillations Perpendicular to B . . . . . . . . 96 4.10 Electrostatic Ion Waves Perpendicular to B . . . . . . . . . . . . . . . 102 4.11 The Lower Hybrid Frequency . . . . . . . . . . . . . . . . . . . . . . . . . 104 4.12 Electromagnetic Waves with B0 ¼ 0 . . . . . . . . . . . . . . . . . . . . . 106 4.13 Experimental Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 4.14 Electromagnetic Waves Perpendicular to B0 . . . . . . . . . . . . . . . 113 4.14.1 Ordinary Wave, E1 ║ B0 . . . . . . . . . . . . . . . . . . . . . . 113 4.14.2 Extraordinary Wave, E1 ⊥ B0 . . . . . . . . . . . . . . . . . . . 115 viii Contents4.15 Cutoffs and Resonances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 4.16 Electromagnetic Waves Parallel to B0 . . . . . . . . . . . . . . . . . . . 120 4.17 Experimental Consequences . . . . . . . . . . . . . . . . . . . . . . . . . . 122 4.17.1 The Whistler Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 122 4.17.2 Faraday Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 4.18 Hydromagnetic Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 4.19 Magnetosonic Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 4.20 Summary of Elementary Plasma Waves . . . . . . . . . . . . . . . . . . 134 4.21 The CMA Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 5 Diffusion and Resistivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 5.1 Diffusion and Mobility in Weakly Ionized Gases . . . . . . . . . . . 145 5.1.1 Collision Parameters . . . . . . . . . . . . . . . . . . . . . . . . . 145 5.1.2 Diffusion Parameters . . . . . . . . . . . . . . . . . . . . . . . . . 147 5.2 Decay of a Plasma by Diffusion . . . . . . . . . . . . . . . . . . . . . . . 148 5.2.1 Ambipolar Diffusion . . . . . . . . . . . . . . . . . . . . . . . . . 148 5.2.2 Diffusion in a Slab . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 5.2.3 Diffusion in a Cylinder . . . . . . . . . . . . . . . . . . . . . . . . 153 5.3 Steady State Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 5.3.1 Constant Ionization Function . . . . . . . . . . . . . . . . . . . 154 5.3.2 Plane Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 5.3.3 Line Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 5.4 Recombination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 5.5 Diffusion Across a Magnetic Field . . . . . . . . . . . . . . . . . . . . . . 157 5.5.1 Ambipolar Diffusion Across B . . . . . . . . . . . . . . . . . . 161 5.5.2 Experimental Checks . . . . . . . . . . . . . . . . . . . . . . . . . 162 5.6 Collisions in Fully Ionized Plasmas . . . . . . . . . . . . . . . . . . . . . 164 5.6.1 Plasma Resistivity . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 5.6.2 Mechanics of Coulomb Collisions . . . . . . . . . . . . . . . . 167 5.6.3 Physical Meaning of η . . . . . . . . . . . . . . . . . . . . . . . . 169 5.6.4 Numerical Values of η . . . . . . . . . . . . . . . . . . . . . . . . 171 5.6.5 Pulsed Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 5.7 The Single-Fluid MHD Equations . . . . . . . . . . . . . . . . . . . . . . 172 5.8 Diffusion of Fully Ionized Plasmas . . . . . . . . . . . . . . . . . . . . . 174 5.9 Solutions of the Diffusion Equation . . . . . . . . . . . . . . . . . . . . . 176 5.9.1 Time Dependence . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 5.9.2 Time-Independent Solutions . . . . . . . . . . . . . . . . . . . . 177 5.10 Bohm Diffusion and Neoclassical Diffusion . . . . . . . . . . . . . . . 178 6 Equilibrium and Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 6.2 Hydromagnetic Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . 188 6.3 The Concept of β . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Contents ix6.4 Diffusion of Magnetic Field into a Plasma . . . . . . . . . . . . . . . . 192 6.5 Classification of Instabilities . . . . . . . . . . . . . . . . . . . . . . . . . . 196 6.5.1 Streaming instabilities . . . . . . . . . . . . . . . . . . . . . . . . 197 6.5.2 Rayleigh–Taylor instabilities . . . . . . . . . . . . . . . . . . . 197 6.5.3 Universal instabilities . . . . . . . . . . . . . . . . . . . . . . . . . 197 6.5.4 Kinetic instabilities . . . . . . . . . . . . . . . . . . . . . . . . . . 198 6.6 Two-Stream Instability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 6.7 The “Gravitational” Instability . . . . . . . . . . . . . . . . . . . . . . . . . 202 6.8 Resistive Drift Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 6.9 The Weibel Instability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 7 Kinetic Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 7.1 The Meaning of f(v) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 7.2 Equations of Kinetic Theory . . . . . . . . . . . . . . . . . . . . . . . . . . 217 7.3 Derivation of the Fluid Equations . . . . . . . . . . . . . . . . . . . . . . 222 7.4 Plasma Oscillations and Landau Damping . . . . . . . . . . . . . . . . 224 7.5 The Meaning of Landau Damping . . . . . . . . . . . . . . . . . . . . . . 230 7.5.1 The Kinetic Energy of a Beam of Electrons . . . . . . . . . 233 7.5.2 The Effect of Initial Conditions . . . . . . . . . . . . . . . . . 237 7.6 A Physical Derivation of Landau Damping . . . . . . . . . . . . . . . 238 7.6.1 The Resonant Particles . . . . . . . . . . . . . . . . . . . . . . . . 242 7.6.2 Two Paradoxes Resolved . . . . . . . . . . . . . . . . . . . . . . 243 7.7 BGK and Van Kampen Modes . . . . . . . . . . . . . . . . . . . . . . . . 244 7.8 Experimental Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 7.9 Ion Landau Damping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 7.9.1 The Plasma Dispersion Function . . . . . . . . . . . . . . . . . 250 7.9.2 Ion Waves and Their Damping . . . . . . . . . . . . . . . . . . 252 7.10 Kinetic Effects in a Magnetic Field . . . . . . . . . . . . . . . . . . . . . 256 7.10.1 The Hot Plasma Dielectric Tensor . . . . . . . . . . . . . . . . 257 7.10.2 Cyclotron Damping . . . . . . . . . . . . . . . . . . . . . . . . . . 259 7.10.3 Bernstein Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 8 Nonlinear Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 8.2 Sheaths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 8.2.1 The Necessity for Sheaths . . . . . . . . . . . . . . . . . . . . . 269 8.2.2 The Planar Sheath Equation . . . . . . . . . . . . . . . . . . . . 270 8.2.3 The Bohm Sheath Criterion . . . . . . . . . . . . . . . . . . . . 272 8.2.4 The Child–Langmuir Law . . . . . . . . . . . . . . . . . . . . . 273 8.2.5 Electrostatic Probes . . . . . . . . . . . . . . . . . . . . . . . . . . 274 8.3 Ion Acoustic Shock Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 8.3.1 The Sagdeev Potential . . . . . . . . . . . . . . . . . . . . . . . . 277 8.3.2 The Critical Mach Numbers . . . . . . . . . . . . . . . . . . . . 279 x Contents8.3.3 Wave Steepening . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 8.3.4 Experimental Observations . . . . . . . . . . . . . . . . . . . . . 282 8.3.5 Double Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 8.4 The Ponderomotive Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 8.5 Parametric Instabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 8.5.1 Coupled Oscillators . . . . . . . . . . . . . . . . . . . . . . . . . . 287 8.5.2 Frequency Matching . . . . . . . . . . . . . . . . . . . . . . . . . 288 8.5.3 Instability Threshold . . . . . . . . . . . . . . . . . . . . . . . . . 291 8.5.4 Physical Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . 293 8.5.5 The Oscillating Two-Stream Instability . . . . . . . . . . . . 295 8.5.6 The Parametric Decay Instability . . . . . . . . . . . . . . . . 298 8.6 Plasma Echoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 8.7 Nonlinear Landau Damping . . . . . . . . . . . . . . . . . . . . . . . . . . 304 8.8 Equations of Nonlinear Plasma Physics . . . . . . . . . . . . . . . . . . 307 8.8.1 The Korteweg–de Vries Equation . . . . . . . . . . . . . . . . 307 8.8.2 The Nonlinear Schr€ odinger Equation . . . . . . . . . . . . . . 312 8.9 Reconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 8.10 Turbulence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 8.11 Sheath Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 9 Special Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 9.1 Non-Neutral Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 9.1.1 Pure Electron Plasmas . . . . . . . . . . . . . . . . . . . . . . . . 333 9.1.2 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 9.2 Solid, Ultra-Cold Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 9.3 Pair-ion Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 9.4 Dusty Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 9.4.1 Dust Acoustic Waves . . . . . . . . . . . . . . . . . . . . . . . . . 342 9.4.2 Dust Ion-acoustic Waves . . . . . . . . . . . . . . . . . . . . . . 344 9.5 Helicon Plasmas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 9.6 Plasmas in Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 9.7 Atmospheric-Pressure Plasmas . . . . . . . . . . . . . . . . . . . . . . . . 350 9.7.1 Dielectric Barrier Discharges . . . . . . . . . . . . . . . . . . . 351 9.7.2 RF Pencil Discharges . . . . . . . . . . . . . . . . . . . . . . . . . 352 10 Plasma Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 10.2 Fusion Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 10.2.1 Magnetic Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 10.3 Plasma Accelerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 10.3.1 Free-Electron Lasers . . . . . . . . . . . . . . . . . . . . . . . . . 392 10.4 Inertial Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 10.4.1 Glass Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 10.4.2 KrF Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 Contents xi10.5 Semiconductor Etching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 10.6 Spacecraft Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 10.6.1 General Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 10.6.2 Types of Thrusters . . . . . . . . . . . . . . . . . . . . . . . . . . . 407 10.7 Plasmas in Everyday Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 Appendix A: Units, Constants and Formulas, Vector Relations . . . . . . . 413 Appendix B: Theory of Waves in a Cold Uniform Plasma . . . . . . . . . . . 417 Appendix C: Sample Three-Hour Final Exam . . . . . . . . . . . . . . . . . . . . 423 Appendix D: Answers to Some Problems . . . . . . . . . . . . . . . . . . . . . . . . 429 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485

Francis F. Chen, known as Frank in the physics community, got his B.A. from Harvard Observatory in 1950. His all-star oral committee consisted of famous astronomers Harlow Shapley, Bart J. Bok, Donald Menzel, and Earl Whipple. With pulsars and quasars still undiscovered, he switched to High Energy Physics, receiving his Ph.D. from Harvard in 1954. He had been sent by his adviser, Nobelist Norman Ramsey, to Brookhaven National Laboratory, where he worked on the Cosmotron and wrote the first experimental thesis for energies at or above 1 GeV. To avoid the Korean War draft, he then went to work for the astronomer Lyman Spitzer, Jr., who had just started the classified Project Matterhorn at Princeton University. This was one of four initial projects in the U.S. to tame the hydrogen bomb to make energy peacefully from the same reaction. In 1954, Chen was one of the first 15 employees at what is now the Princeton Plasma Physics Laboratory (PPPL). Project Matterhorn started in two old buildings, one formerly a rabbit hutch, and the other a horse operating room. Chen inherited the Model B1 Stellarator, built by James van Allen of the famous van Allen radiation belts around the earth. With the B1, Chen was the first to show that electrons could be trapped by a magnetic field for millions of traverses. By then, it was clear that fusion would require trapping a plasma, a hot, ionized gas of electrons and ions, and not just electrons. Subsequent Model B stellarators, however, failed to do this for longer than milliseconds. Realizing that stellarators were magnetic bottles that were curved and not straight, he convinced Spitzer to allow him to build straight machines to isolate the problem, even though these would have leaks at the ends. Chen then built the L-1 and L-2 machines with straight magnetic fields. Experiments on these showed that the plasma was lost by turbulence, and these random motions were aligned along the magnetic field, with wavelengths longer than any plasma waves known at that time. While on sabbatical in Paris, Chen figured out what these new waves were. They are now known as resistive drift waves and were discovered simultaneously in Russia by Sagdeev and Pogutse. In L-2, Chen and Mosher showed how this turbulence could be suppressed by magnetic fields that were not totally straight but had what is called shear. Modern magnetic bottles (called tokamaks), using advanced methods of stabilization, can hold a hot plasma for minutes. In 1969, Chen went from Princeton to UCLA in California, where he organized an academic program in plasma physics. He wrote the first undergraduate textbook in this field in 1973. Soon after, however, powerful lasers were invented, opening up a whole new field of research. Chen then left magnetic fusion to help start the field of laser fusion. He built the first laser at UCLA. In basic experiments, he and his students were among the first to study Brillouin and Raman scattering, two instabilities that cause problems even in laser-produced plasmas. This interesting field led to John Dawson’s discovery of plasma accelerators, which can shrink the size of machines for high-energy particle research by a factor of 1000! Chen recruited C. Joshi, whose experimental acumen has led his group to spectacular successes. Meanwhile, Chen left the effort to join yet another nascent field: low-temperature plasma physics. This involves partially ionized gases which include neutral atoms as well as ions and electrons. This complexity had led to its reputation as dirty science. By developing helicon plasma sources, which are magnetized, Chen showed that radiofrequency gas discharges contain very interesting physics which can be treated in a logical and interesting manner. Chen’s 57-year career in plasma physics can be divided into four approximately equal parts: magnetic fusion, laser fusion and laser accelerators, low-temperature plasma physics, and plasma diagnostics. In the last of these, Chen is an authority on the theory and use of Langmuir probes for local measurements of plasma density and electron temperature in different environments. He is the only physicist who has had significant publications in both theory and experiment in both the fields of magnetic and laser fusion. Outside of science, Chen enjoys the outdoors and is solicitous about the environment. He has been a pole-vaulter, soccer player and coach, backpacker, kayaker, and marathoner, and still plays tennis. He is a bird photographer, and he and his wife Ande have birded on all seven continents. She leads a bird and wildflower hike every weekend in the spring. They are concerned about the effect of climate change on wildlife species.

暂无其它内容！

暂时还没有人为这本书评论！