Plasma Engineering

Applications from Aerospace to Bio and Nanotechnology

Michael Keidar, Isak Beilis

• Publisher: Academic Press
• Year: 2013
• ISBN:
  9780123859785
• Topic: Technik & Maschinenbau
• Subtopic: Elektrotechnik & Telekommunikation

Plasma Engineering is the first textbook that addresses plasma engineering in the aerospace, nanotechnology, and bioengineering fields from a unified standpoint. It covers the fundamentals of plasma physics at a level suitable for an upper level undergraduate or graduate student, and applies the unique properties of plasmas (ionized gases) to improve processes and performance over a wide variety of areas such as materials processing, spacecraft propulsion, and nanofabrication.

The book starts by reviewing plasma particle collisions, waves, and instabilities, and proceeds to diagnostic tools, such as planar, spherical, and emissive probes, and the electrostatic analyzer, interferometric technique, and plasma spectroscopy. The physics of different types of electrical discharges are considered, including the classical Townsend mechanism of gas electrical breakdown and the Paschen law. Basic approaches and theoretical methodologies for plasma modeling are described, based on the fluid description of plasma solving numerically magnetohydrodynamic (MHD) equations and the kinetic model particle techniques that take into account kinetic interactions among particles and electromagnetic fields. Readers are then introduced to the widest variety of applications in any text on the market, including space propulsion applications and application of low-temperature plasmas in nanoscience and nanotechnology. The latest original results on cold atmospheric plasma (CAP) applications in medicine are presented. The book includes a large number of worked examples, end of chapter exercises, and historical perspectives. There is also an accompanying plasma simulation software covering the Particle in Cell (PIC) approach, available at http://www.particleincell.com/blog/2011/particle-in-cell-example/.

This book is appropriate for grad level courses in Plasma Engineering/Plasma Physics in departments of Aerospace Engineering, Electrical Engineering, and Physics. It will also be useful as an introduction to plasma engineering and its applications for early career researchers and practicing engineers.

• The first textbook that addresses plasma engineering in the aerospace, nanotechnology, and bioengineering fields from a unified standpoint
• Includes a large number of worked examples, end of chapter exercises, and historical perspectives
• Accompanying plasma simulation software covering the Particle in Cell (PIC) approach, available at http://www.particleincell.com/blog/2011/particle-in-cell-example/

Chapter 1

Plasma Concepts

1.1 Introduction

When a neutral gas is ionized, it behaves as a conductive media. Ionization process is the phenomenon associated with striping electrons from the atoms thus creating the pair of negatively and positively charged particles. Electrical properties of such ionized gas depend on the charged particle density. One of the most important distinctions between the ionized gas and the neutral media is that Coulomb interaction between charged particles determines the dynamic of the gas. Ionized gas is able to conduct the current. This property is of particular interest in the presence of the magnetic field when the interaction of the current and magnetic field leads to electromagnetic body force thus altering its flow dynamics. There are weakly ionized gases and strongly ionized gases. Weekly ionized gas is characterized by a relatively small fraction of charged particles and its behavior can be largely described by neutral gas laws while one needs to invoke electrodynamics to describe appropriately the strongly ionized media. We shall call a physical state of an ionized gas in which the densities of positively and negatively charged particles are approximately equal as a quasi-neutrality state. Plasma is defined as an ionized gas, which satisfies the quasi-neutrality condition.

Development of the plasma physics was always associated with particular applications. Starting from lighting sources, current interrupters, thermonuclear fusion, and plasma accelerators, nowadays plasma applications range from plasma processing, space propulsion, nanotechnology, and plasma medicine.

Prominent physicists contributed to developing the field of the plasma physics and engineering. Irving Langmuir (1881–1957) initiated an active study of the plasma as a new direction of science. The term “plasma” was introduced in 1928 in his article describing the positive column of low-pressure gas discharge. While Langmuir introduced the term plasma, the matter in the plasma state was known to human since much early times. Lighting, northern light, solar wind, and Earth ionosphere are some examples of plasmas. Irving Langmuir received the Nobel Prize in Chemistry, 1932. Mott-Smith indicated in his letter [1] that Langmuir takes the term by analogy between “the blood plasma carries around red and white corpuscles and germs” and the multicomponent ionized gas. The great success in developing the foundation of the plasma science was achieved by Langmuir due to effective collaboration with his famous coworkers Compton, Tonks, Mott-Smith, Jones, Child, and Taylor.

Hannes Alfven (1908–1995) is widely known, as a father of the plasma magnetohydrodynamics. He developed theories regarding the nature of the galactic magnetic field and space plasmas. Prof. Alfven received a Nobel Prize in Physics in 1970 for “fundamental work and discoveries in magnetohydrodynamics.”

Plasma physics, as it is known today, was developed over last 50 years and encompasses many areas ranging from the high-temperature plasmas of thermonuclear fusion to the low-temperature plasma in material processing. The plasma fundamentals and configurations for thermonuclear fusion applications were formulated and developed by Igor Tamm, Andrei Sakharov, Lev Artzimovich, Marshall Rosenbluth, Lyman Spitzer, and many others. Science of the interstellar ionized medium and astrophysical plasmas was by Yakov Zeldovich and Vitaly Ginsburg. Gas discharge plasma physics was introduced by A. von Engel, M. Steenbeck, and then developed by Loeb, Townsend, Thomson, Kaptzov, Granovsky, and Raizer.

In the following as a way of introduction to plasma physics, we will discuss some basic plasma properties. It can be indicative of what kind of plasma is considered by analyzing two main characteristics of plas...