Plasma nonequilibrium

L.I. Slovetskii, Mekhanizmy Khimicheskikh Reaktsii v Neravno-vesnoi Plazme (Mechanisms of Chemical Reactions in Nonequilibrium Plasma), Moscow Nauka, 1980, 310p. 

Further investigations proved an assumption stated before, concerning destruction of cyanide complexes and cyanide ions under the action of nonequilibrium plasma [5], A number of experiments on destructing cyanide ions were conducted both in model solutions and technological solutions containing complex cyanides of various metals (composition of the solutions is given in Table 1.). 

The gas-phase corona reactor (GPCR) uses high-voltage alternating-current fields to create a nonequilibrium plasma that destroys volatile organic compounds (VOCs) in off-gas products. 

DBDs are nonequilibrium plasmas at atmospheric pressure with applications in ozone generation, surface modification, pollution control, excimer lamps, and recently also in flat plasma display panels (Kogelschatz, 2003). Typical planar DBD configurations are shown in Figure 2. They have at... 

Preparation of plasma polymer/metal films in low temperature nonequilibrium plasmas is generally based on a combination of two processes applied simultaneously ... 

Figure 1.3 clearly demonstrates the luminous gas phase created under the influence of microwave energy coupled to the acetylene (gas) contained in the bottle. This luminous gas phase has been traditionally described in terms such as low-pressure plasma, low-temperature plasma, nonequilibrium plasma, glow discharge plasma, and so forth. The process that utilizes such a luminous vapor phase has been described as plasma polymerization, plasma-assisted CVD (PACVD), plasma-enhanced CVD (PECVD), plasma CVD (PCVD), and so forth. 

In the present chapter the attention will be focussed on processes of molecular dissociation under nonequilibrium plasma conditions. 

A plasma is an efficient way to dissociate gas molecules to produce non-equilibnum concentrations of gas-phase species, such as the high concentrations of atomic hydrogen needed for diamond growth. Plasmas can be generated by a number of energy sources (microwave, radio-frequency, or direct-current electric fields), and can be either cold (non-isothermal, or nonequilibrium plasmas) or hot (isothermal, or equilibrium plasmas). The major characteristics of these plasmas are summarized in Table 3. 

For the understanding of plasma properties and for the control of a plasma reactor, it is important to detect electrons, ions, and other active species present in a plasma and to measure their densities. To this end, various methods have been developed, including measurements of radicals by absorption spectroscopy (Anderson et al, 1999) or optical-emission spectroscopy, measurements of electron densities and electric fields by probes, and measurements of ions by mass spectrometry (Matsuda et al, 1983 Robertson et al, 1983). In particular, neutral and nonemitting radicals (for instance, radicals in the electronic ground state) are expected to be abundantly present in a nonequilibrium plasma and have become measurable recently (Sugai et al., 1995 Cosby, 1993 Mi and Bonham, 1998 Motlagh and Moore, 1998). 

Fujishiro, S., Garscadden, A., and Makabe, T. (Eds.) (1998). Papers from the International Workshop on Basic Aspects of Nonequilibrium Plasmas Interacting with Surfaces, Shirahama, Wakayama, Japan, January 26-27, 1997, published in J. Vac. Sci. Technol. A 16, 215 (1998). 

Chemical reactions initiated in gas discharges and plasmas, in particular in low-temperature, nonequilibrium plasmas, have become indispensable for the advancement of many key technologies in the past 10-15 years (see, e.g Becker et al., 1992 Garscadden, 1992). The plasma-assisted etching of microstructures and the deposition of high-quality thin films with well-defined properties have become crucial steps in the fabrication of microelectronic devices with typical feature sizes of less than 0.5 /rm. The manufacture of state-of-the-art microchips now involves hundreds of process steps, most of them serial, to yield circuits with millions of discrete elements and interconnections in an area of a single square centimeter (Garscadden, 1992). Each step is a physical-chemical interaction that must be controlled. More than one-third of the process steps rely on plasma... 

H.E. Wagner, R. Brandenburg, K.V. Kozlov, Cross correlation emission spectroscopy application to nonequilibrium plasma diagnostics, Proceedings of Frontiers in Low Temperature Plasma Diagnostics V (2003)... 

Figure 5-63. Limitations of ionization degree for high-energy-effieieney water dissoeiation and hydrogen production in nonequilibrium plasma-ehemieal proeess organized in H2O-CO2 mixture of different eomposition.

Use relation (10-54) to estimate the front velocity of solid-state (coal) oxidation at low temperatures. How does the oxidation front velocity depend on temperature Which effects determine the temperature limit for acceleration of the oxidation front In which way does nonequilibrium plasma stimulate the process ... 

Anikin, N.B., Mintoussoy E.I., Pancheshnyi, S.V, Roupassoy D.V, Sych, VE., Starikovskii, A.Yu. (2003), Nonequilibrium Plasma and Its Application for Combustion and Hypersonic Flow Conrol, 41st AIAA Aerospace Sciences Meeting and Exhibit, January 9-12, Reno, NV, AIAA Paper 2003-1053. 

Plasma treatment refers to the surface modification processes of materials using nonequUibrium gas plasmas. Nonequilibrium plasmas with a low degree of ionization, so-called cold plasmas or low-temperature plasmas, are mainly composed of electrons, ions, free radicals, and electronically excited atomic and molecular species. These highly reactive plasma species interact nonthermally with material surfaces and can react with and bond to various substrate surfaces or combine together to form an ultrathin layer of plasma coating and consequently alter the surface chemistry and surface properties. The plasma-treated nanoparticles and/or nanotubes with desired surface functionalities can strongly interact with liquid molecules and thus better disperse into the base fluid to form stable suspension. 

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