The relaxation to equilibrium of an ensemble of electrons dilutely dispersed in a large excess of CH4 is studied with solutions of the Boltzmann equation. Elastic and vibrationally inelastic collision processes are included in the analysis. The relaxation time for the approach to equilibrium defined for the relaxation of the average electron energy is determined for two different cross section sets. The kinetic theory formalism, based on the Boltzmann equation, is compared with the formalism used in radiation chemistry and physics and based on the Spencer–Fano equation.

The one-particle Green's function method in the Dirac-Hartree-Fock framework. I. Second-order valence ionization energies of Ne through Xe Dissociative electron attachment near threshold, thermal attachment rates, and vertical attachment energies of chloroalkanesThe relaxation of a nonequilibrium distribution of electrons in a mixture of CCl 4 with either Ar or Ne is studied. In this paper, electron-CCl 4 and electron-inert gas elastic collisions, vibrationally inelastic collisions between electrons and CCl 4 , as well as the electron attachment reaction with CCl 4 , are included in the analysis. The time dependent electron energy distribution function is determined from the Boltzmann equation and the energy relaxation times are determined. The coupling of the thermalization process and the attachment process are discussed in detail. The results from the calculations are analyzed analogous to experimental studies, and the methodology of the experimental reduction of the data is studied.

The apparent decay rates of hydrogen and deuterium atoms in the reactions with acetylene-d0 and -d2 in helium in the pressure range from 100 to 800 Torr (1 Torr=133.3 Pa) have been measured by the pulse radiolysisLyman-α absorption method at 300±2 K. The helium pressure dependence of the rate constants was well interpreted in terms of the RRKM theory including a tunneling effect, using the geometry and force constants of the activated complex and vinyl radical estimated by the ab initio calculation. (S. Nagase and C. W. Kern, J. Am. Chem. Soc., 101, 2544 (1979).)

By using the cross sections derived by the binary encounter collision theory and the assumption of a continuous slowing down, the G-values for the ionization and excitation of helium gas irradiated by α-, β-, and γ-rays have been calculated. In the radiolysis by high-energy electrons, the G-values started to decrease at an incident electron energy of about 103 eV with a decrease in the energy. Calculation showed that, if the radiation energy is extremely high, the G-values are independent of the kind of radiation. In the radiolysis induced by α-particles, the ratio of the yield resulting from the direct interaction with α-particles to that due to the secondary electrons was calculated as a function of the energy of the incident α-particles. When the energy was 8 MeV, the ratio for ionization was calculated to be 1.31.

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