We have carried out a comprehensive theoretical and experimental study of electron scattering from molecular nitrogen at energies below 10.0 eV. In the theoretical component of this project we have generated differential and integral cross sections for elastic scattering and vibrational excitation in converged vibrational close-coupling calculations. In the experiments, we have measured dift'erential cross sections for these processes at scattering angles from 20' to 130 in a crossed-beam experiment at a large number of energies between 0.55 and 10 eV and, in a complementary time-of-Right experiment, total cross sections at energies between 0.08 and 10.0 eV. The measured angular distributions have been extrapolated to 0 and 180 using a procedure based on a nonlinear least-squares fit constrained by known physical properties of the e-Nz scattering matrix; numerical integration of the resulting extrapolated distributions yields integrated cross sections with almost no error beyond that inherent in the measured angular data. We find generally good agreement between the present experimental and theoretical cross section, particularly at energies near the H~r esonance near 2.39 eV. In previous studies of scattering in this region, such comparisons have been made problematical by the difhculty of ascertaining the appropriate theoretical scattering energy. We recommend here a protocol for resolving this problem for both elastic scattering and vibrational excitation.PACS number(s): 34.80.6s

The authors report absolute differential cross-section measurements for vibrationally elastic electron scattering from NH3 at incident energies from 2-30 eV. The present results, from a crossed electron-molecular beam apparatus, represent the first comprehensive experimental attempt to quantify the elastic electron-NH3 scattering process. At each energy studied they have integrated their differential cross-section data to generate total elastic and elastic momentum transfer cross sections and a critical comparison of both their differential and integral cross sections against previous experiment and theory is provided. They also report their observation of a strong Feshbach resonance in the elastic channel at energy of 5.59+or-0.05 eV.

and total scattering cross sections for low-energy (0.1-7.OeV) electron scattering from neon have been measured. Both data sets have been analysed Using phaseshift techniques and comparisons are made between the present cross sections and phaseshifb and similar data from previous swarm and beam experiments, and theory. We also discuss the present data in the context of the recent proposal by Shi and Bunow regarding the use of neon as a secondary elastic cross section 'standard'.

We report differential and integral cross sections for elastic scattering and rovibrational [ v = 0-1) excitation of H, by electrons at seven energies in the range 1-5 eV.The measurements were conducted on a fine energy grid in an attempt to resolve an impasse that had arisen between theory and 'swarm' derived cross sections and to enable a detailed comparison to be made with the best available theoretical calculations.