In the present paper, the xenon plasmas containing argon and caesium as additives and pertaining to the above-mentioned type (high-pressure, low-temperature) are studied, and a theoretical evaluation of their basic transport parameters are presented. The numerical calculations were based on the assumption that the system is kept under constant pressure and temperature and has attained local thermodynamical equilibrium (LTE). Particular attention is given to the evaluation of electron collision frequencies within the temperature interval from 2000 to 20000K, and for initial pressures ranging from 0.1 to 1.5 MPa in plasmas in the mixtures of xenon, argon and caesium. The equilibrium plasma composition was evaluated with the use of the modified Debye radius.

It is found that the addition of as little as 1% of caesium profoundly alters the properties of the plasma. The presence of the added caesium in the thermal xenon and argon plasma is indeed quite significant for its transport properties, especially at temperatures below and around 10000K. Thus, electron number density, monotonically increasing with temperature (with pressure kept constant) much as in the pure noble-gas plasma, becomes considerably higher. The characteristics of the electrical and thermal conductivities are basically caused by the specificities of the processes of thermal ionization taking place in the system considered, as these processes determine the multiplier electron number density.