No abstract

No abstract

No abstract

The kinetics of argon dimer (Ar * 2) are studied in detail by model calculations. The model is applicable to discharge as well as e-beam excitation of high-pressure argon gas. The time-transient behaviour of the temperature and the vibration-translational relaxation of the excited state dimer have been considered in the model calculations. The model validity is verified by comparing the model predictions with discharge and e-beam experiments. Excellent agreement has been reached for the e-beam experiments. The predicted discharge voltage and current waveforms are in good agreement with the experiments of Ninomiya and Nakamura. The predicted net gain of 0.002 cm −1 at 3.5 atm is about three times smaller.

Present-day computational techniques provide a possibility of evaluating properties of macrosystems using ab initio quantum chemistry and theories of elementary processes. Physical and chemical phenomena on very different timescales have to be taken into account (excitation, emission, chemical reactions, diffusion) at different levels of refining. This refining covers a very wide region of parameters starting from the structure of species up to the macro chemical mechanism of their conversion. This multilevel approach is described in detail in the paper and includes interaction and data transfer between different levels of phenomena description. In the framework of the approach, unknown properties of molecules, ions and atoms (structure, potential energy curves, transition dipole moments) are calculated based on quantum-chemical methods. The calculation results are used to evaluate rate characteristics of physical and chemical processes. The developed kinetic state-to-state scheme is then used to calculate the macro properties of the system under investigation. As an example of the multilevel approach, the emission properties of the Ar–GaI3 positive column discharge plasma were calculated using the Chemical Work Bench computational environment. The calculations yield the electron energy balance and emission efficiency as functions of plasma parameters.