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Results of experimental studies on high-pressure ethylene polymerization in industrial autoclave and tubular reactors are considered using various peroxides and their mixtures with oxygen as initiators. A possibility for the process improvement providing the increase of conversion, productivity and versatility of the obtained polyethylene brands is demonstrated. According to the experimental data for the processes performed in single- and double-zone mixing mode reactors the initiator consumption, temperature profile stability and possibilities for rapid control over the process are analyzed depending on the type of the used peroxides or their complex mixtures. Peculiarities of ethylene polymerizations in tubular reactors using the initiators either individually (stepwise initiation) or in a complex (mixed) initiation mode are revealed and discussed.

A thermodynamic analysis of the doping of silica glass with nitrogen by the chemical vapor deposition methods has been carried out. The fundamental differences are revealed between the plasma chemical vapor deposition and modified chemical vapor deposition methods. The basic parameters of nitrogen introduction into silica glass are determined by thermodynamic calculations. It is found that the main factor that ensures doping of silica glass with nitrogen by the modified chemical vapor deposition is an extremely low partial oxygen pressure in the reaction zone. The results of theoretical analysis are used in practice for nitrogenizing silica glass by modified chemical vapor deposition. The increment in the refractive index is equal to 0.0015.

Experimental results of comparative tests of a spark ion source (closed geometry) with a MEVVA ion source (open geometry) are presented in this paper. Carbon (graphite) and some pure metals (such as Al, Cu, Ta) have been used as the working substances. It was discovered that the vapor ionization degree in the spark depended on the discharge gap shape that changed in time and became self‐sustaining during the tests. It is supposed that this dependence had been determined both by the considerably increased value of power density released in the discharge, accompanied by the intense working substance transfer, and by a voltage drop growth in the spark ion source which led to deeper ionization of the vapors by fast electrons. Prolonged tests of the closed shape ion source (22 000 pulses, f=0.3 Hz) have been carried out. Spectra have been obtained for different times from the beginning of the test. Results are discussed.

On the basis of the results reported in Ref. [9], the rate constant for the reaction O+CO+O2→CO2+O2 can be expressed as k=6.5×10−36 (3700/RT) cm3 mol−1s−1 in the temperature range of 400–500 K. It is suggested that the negative activation energy can be accounted for by the mechanism is a stabilized, excited ozone molecule, possibly in the triplet state.

The reaction between carbon monoxide and atomic oxygen was studied in a gas flow over a temperature range of 136 to 230°C at atmospheric pressure. The rate constant of this reaction, considered to be one for a second-order reaction, was found to decrease with increasing temperature and to depend on the ratio of O2 to CO that was varied from 0.11 to 2.69. A conclusion was made that under the experimental conditions the reaction was third order The rate constant of this reaction was determined for a mixture of O2 and CO and it was found that the efficiency of O2 as particle M is four times that of CO.

A set of kinetic constants which make it possible to obtain equations for spatial and time functions of particle concentrations (allowance being made, certainly, for macroscopic factors such as mass- and energy exchange) is the main object of investigations on elementary reactions. The number of elementary reaction types encountered in plasma is great, and it is not intended to give here a full account of the present state of the field which is the subject of many monographs.

To find out the mechanism of a chemical reaction and the nature of its elementary processes it is very important to know whether the reaction occurs in the homogeneous (gas) phase only, or whether heterogeneous factors are also involved. With gas reactions such a factor usually is the reactor wall. The importance of the reactor wall, in particular of its nature and relative surface area in the kinetics of chemical gas reactions was first noticed by van’t Hoff [499].

The rate of a chemical reaction is determined by the changes in concentrations of the reactants (or of reaction products) with time. The concentration is usually measured by the number of moles of the given species per unit volume, i.e. by the value c = N/V mol/cm3 (N is the number of moles, V is the volume in cm3) or by the number of molecules per unit volume (number density) n = cNA molecule/cm3, where NA = 6.02 · 1023 molecules per mole is the Avogadro number. Sometimes the concentration is measured by the mass of the species per unit volume in grams, i.e. by the species density ρ = mn (m is the molecular mass) and also by partial pressure p = nkT = (ρ/m) kT.