Abstract:

The purpose of the present paper is to evaluate the swarm parameters in CF3I+CF4+Ar ternary gas mixtures with dilute CF3I components. The swarm parameters reported are namely, ionization, attachment, effective ionization, excitation rates and electron mean energies.  We present the swarm data of the ternary mixture for various CF4+Ar base mixtures with dilute CF3I concentrations and analyze positive synergism in terms of attachment, ionization and excitation rates in the E/N range of 50–700 Td (1 Td = 10-21 Vm2).  In the ternary mixture, Ar component of the ternary mixture is kept constant at concentrations in the range of 40% - 90% and the CF3I component is increased from 0.5% to 55%. In the dilute CF3I mixtures, there is a marked increase in the electronegativity together with increased total excitation rates while the CF3I component is increased. The mean energy of electrons is also reduced with increasing CF3I content at given E/N accordingly. The limiting E/N values are obtained at the E/N values where the rate of ionization is equal to the rate of attachment. The limiting E/N increases in the ternary mixture as the CF3I ratio is increased in the present study. The synergism is calculated using the Boltzmann solution results of the limiting E/N fields. Positive synergism is observed within the parameter range of this study. The degree of synergy is very high with dilute CF3I components.

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