Modeling and Simulation - Nonthermal Plasma Chemistry and Physics - page 407

9 Modeling and Simulation

CONTENTS
9.1 Hierarchy of Plasma Models ................................................. 408
9.1.1 PlasmaasaManyParticleSystem.................................. 409
9.1.2 KineticEquation..................................................... 410
9.1.3 Collision Integral of the Boltzmann Equation ...................... 413
9.1.4 MomentsoftheKineticEquation................................... 414
9.1.5 Numerical Methods.................................................. 418
9.1.5.1 FluidEquations ........................................... 419
9.1.5.2 SolutionoftheBoltzmannEquation..................... 422
9.1.5.3 Particle Models ........................................... 424
9.1.5.4 Hybrid Methods........................................... 425
9.2 Elementary Volume Processes in Gas Discharges .......................... 427
9.2.1 Fundamental Concepts .............................................. 430
9.2.1.1 Collision Cross Section................................... 430
9.2.1.2 Formal Scattering Theory ................................ 432
9.2.1.3 AdiabaticApproximation................................. 436
9.2.1.4 Resonant Scattering....................................... 438
9.2.2 TypicalProcesses.................................................... 441
9.2.2.1 Production of Ions ........................................ 441
9.2.2.2 DestructionofIons........................................ 445
9.2.2.3 ExcitationofInternalDegrees............................ 449
9.2.2.4 Concluding Remarks ..................................... 451
9.3 SurfaceProcesses............................................................. 452
9.3.1 Basicsof PlasmaMaterialInteraction.............................. 452
9.3.1.1 Plasma-Wall Contact with an Electron

Emitting Wall ............................................. 454

9.3.2 Interaction of Hydrogen Plasma with Carbon-Based

Materials ............................................................. 455
9.3.2.1 Formation of a Saturated Surface Layer ................. 456
9.3.2.2 Diffusion .................................................. 457
9.3.2.3 Codeposition .............................................. 457

9.4 Example: Oxygen RF Plasma ................................................ 457

Manyplasmasintechnologicalapplicationsareideal,weaklyionized,andnonthermal
as already mentioned in Chapter 2. Hence, the following introduction into plasma
modeling is restricted to this kind of plasma, which covers the large range of pressures
from about 10 − 2 to 10 6 Pa at ionization degrees between about 10 − 6 and 10 − 3 .Over
this range, many different mechanisms and principles of plasma generation as well as

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