Microwave plasma discharge

Handbook of Chemical Vapor Deposition 9.3 Glow-Discharge (Microwave) Plasma... 

Non-thermal plasmas can be produced in a number of ways, including a variety of electrical corona discharges, radio frequency discharges, microwave discharges and electron beams. The most common NTP technologies for emission reduction in engine exhaust streams are the following. 

Figure 22-1 Mass spectrum showing natural isotopes of Pb observed as an impurity in brass. [From Y. Su, Y. Duan, and Z. Jin, Development and Evaluation of a Glow Discharge Microwave-Induced Plasma Tandem Source lor Time-ot-Fllght Mass Spectrometry," Anal. Chem. 3000, 72,5600.]...

Triazane and tetrazane (A//f = 293(10)kJmofr ) were observed mass spectrometrically in a continnons-flow microwave plasma discharge excited in hydrazine gas in helinm. Tetrazane is formed from the dimerization of N2H3 radicals and decomposes to dinitrogen and ammonia. 

In contrast to the study of chemical syntheses in low-pressure, microwave, plasma discharges, the studies of chemical syntheses in atmospheric pressure, thermal plasmas have not given rise to any chemical compound that cannot be prepared by other techniques. The use of thermal plasma discharges does, however, offer a unique source of energized gas available at higher temperatures than normal chemical flames or other, indirect, electric heating techniques. 

Several reports on the activation of lignocellulosic surface by corona discharge, microwave plasma, and ozone treatments have been published (120-22). Strong bonds were produced between thermoplastics and wood by corona treatment of wood surfaces and particularly by treatment of polyethylene and polystyrene surfaces. With 5-min treatment wood—polymer—wood bonds of over 569 psi... 

Sources for atomic spectrometry include flames, arcs, sparks, low-pressure discharges, lasers as well as dc, high-frequency and microwave plasma discharges at reduced and atmospheric pressure (Fig. 5) [28], They can be characterized as listed in Table 2. Flames are in thermal equilibrium. Their temperatures, however, at the highest are 2800 K. As this is far below the norm temperature of most elemental lines, flames only have limited importance for atomic emission spectrometry, but they are excellent atom reservoirs for atomic absorption and atomic fluorescence spectrometry as well as for laser enhanced ionization work. Arcs and sparks are... 

Fig. 103. Capacitively coupled microwave plasma (A) [442] and microwave induced plasma discharges (B, C). (B) MIP in a TMoio resonator according to Beenakker (a) cylindrical wall, (b) fixed bottom, (c) removable lid, (d) discharge tube, (e) holder, (f) coupling loop, (g) PTFE insulator, (h) ...

The decomposition is accomplished using electrically heated filaments, microwave plasma discharge, or direct-current arc discharge. Polycrystalline diamond is deposited as a thin, hard film. 

An afterglow microwave plasma with stabilized pulse power was applied to the activation of zeolite catalysts for isobutane alkylation with butenes. It was found that the pretreatment of zeolite catalysts in a microwave plasma discharge affected their properties. The catalysts exhibited higher activity, stability in operation, and selectivity (the fraction of trimethylpentanes in the alkylate increased). The properties of catalysts after plasma activation depend on the treatment conditions such as plasma temperature and nonequilibrium character and depend only slightly on the initial activity of catalysts, which is primarily controlled by the catalyst preparation conditions. 

The "soft" ionization MS techniques of and FAB have been employed successfully for quantitative applications with stable-isotope-labeled internal standards and interesting developments in the use of microwave plasma discharges, either alone or in combination with mass spectrometic detection, promise to extend the utility of stable isotope labeling methods in quantitative studies of drug dispositon. New methods have been reported for the measurement of N enrichment in ammonia, based on conversion into hexamethylenetetramine, and for the... 

Microwave Plasma Discharge A discharge produced with or without electrodes by microwave fields in stationary or flowing gas streams in a microwave cavity. liquids, gases 1500... 

Non-Equilibrium Plasma-Chemical Microwave Discharges of Moderate Pressure... 

Figure 5—45. Schematic of an experiment with supersonic plasma-chemical microwave discharge (1) CO2 gas inlet system (2) power supply (3) microwave generator (4) tuning system (5) manometer (6) heat exchanger ...

Figure 10-15. Illustration of the plasma catalysis in the steam conversion of kerosene. Additional plasma energy input Aft = 0.2 J/cm (pathway 0-3) leads not to an increase, but to a decrease of temperature in the system. Additional thermal energy input of the equivalent value (pathway 1 -A) results in lower conversion degree and increase of temperature in the system. Curve 2 represents experiments with the plasma-catalytic microwave discharge.

Coal Conversion in Non-Equilibrium Plasma of Microwave Discharges... 

---