We report a theoretical-experimental investigation of electron scattering by dichloromethane (CH 2 Cl 2) in the low-and intermediate energy ranges. Experimental elastic differential cross sections (DCS), in the incident electron energy range of 0.5-800eV and scattering angle range of 10°-130°, were measured using a crossed beam relative flow technique. Integral and momentumtransfer cross sections were determined from the experimental DCS. Theoretical elastic differential, integral, and momentum-transfer, as well as grand-total, and total absorption cross sections were also calculated for impact energies ranging from 0.5 to 500eV. A complex optical Hartree-Fock potential represented the electron-target interaction and a single-center expansion method combined with a Padé approximation was used to solve the scattering equations. Three resonances: a 2 A 1 C-Cl kσ * resonance centered at about 3.5eV, a 2 B 2 C-Cl kσ * resonance centered at about 5eV and a broad 2 A 1 C-H kσ * resonance at about 10eV were detected in our calculation. Further calculations of DCS were performed at an intermediate energy range of 50-800eV, using the independent-atom model in which the atomic complex optical potential and partial-wave method were used to obtain atomic scattering amplitudes. Comparisons of our experimental and theoretical data with very recent experimental and theoretical results are made.

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Normalized experimental differential and integral cross sections for elastic and vibrationally inelastic scattering of low-energy electrons from ethylene (C 2 H 4) have been measured over a large number of incident electron energies and angles. The differential cross sections are measured at incident energies from 0.5 to 100 eV and scattering angles from 5 o to 130 o. These measurements are made to monitor the role of the 2 B 2g (1.8 eV) and the higher 2 B 2u + 2 B 1u + 2 A g (7.5 eV) resonances in the scattering dynamics. Our differential cross section measurements are in very good to excellent agreement with past measurements, and in reasonable agreement with theory as regards forward scattering. A feature in the elastic cross section at 90 o scattering angle at  3.5eV is tentatively associated with the onset of excitation of the ã 3 B 1u triplet electronic state. Differential cross sections for vibrational excitation of four composite energy features in ethylene are also presented from incident energies of 1.25 eV to 15 eV. These results are compared to previous measurements with satisfactory results regarding resonant behavior of these features also concerning the role of the 2 B 2g (1.8 eV) and the higher 2 B 2u + 2 B 1u + 2 A g (7.5 eV) resonances in the scattering dynamics.

We present cross sections from a joint experimental and theoretical study on elastic electron scattering from hexafluoropropene (C3F6) in the gas phase. The experimental results, using low energy electron spectroscopy, were obtained at incident electron energies of 0.5, 1, 1.5, 2, 3, 4, 5, 6, 10, 12, 15 and 20 eV, for scattering angles ranging from 10° to 130°. The theoretical method used in the computation of the integral, momentum transfer and differential cross sections (DCSs) is the Schwinger multichannel method with pseudopotentials. The cross sections were computed in the static-exchange and static-exchange plus polarization approximations for energies up to 20 eV. In general, the present experimental and calculated DCSs agree well among each other, except at 3 eV. Our results also agree well with previous measurements available at 2, 5 and 8 eV. The calculated integral and momentum transfer cross sections display a series of resonances, where the low-lying resonance has a π* character and is located at around 1 eV. This resonance was also observed in previous total cross section measurements at around 1.2 eV (Makochekanwa et al 2005 Eur. Phys. J. D 35 249).

We report a joint theoretical–experimental investigation on elastic electron scattering by chlorobenzene in the low- and intermediate-energy ranges as a part of a collaborative project established between the Federal University of São Carlos (UFSCar) and the California State University (CSUF). More specifically, experimental elastic differential cross sections (DCS), in the incident electron energy range of 1.0 to 800 eV and scattering angle range of 10° to 130°, were measured using the crossed-beam relative-flow technique. Integral and momentum-transfer cross sections were determined from the numerical integration over the experimental DCS. Theoretically, elastic differential, integral, and momentum-transfer cross sections were calculated using a combination of a molecular complex optical potential model with the Padé approximant technique for impact energies ranging from 1.0 to 150 eV. Further calculations of DCS were performed at an energy range of 20 to 500 eV using the independent-atom model. Our results, which significantly extend available electron scattering cross sections for this target, are compared to existing theoretical and experimental data in the literature.