DIFFERENTIAL AND INTEGRAL CROSS-SECTIONS FOR ELASTIC-SCATTERING OF LOW-ENERGY ELECTRONS BY O-2

Differential and integral cross sections for the elastic scattering of electrons by unoriented oxygen molecules have been calculated and mea sured for selected impact energies in the range from 5 to 20 eV. The p resent theoretical results were obtained using the R-matrix method. Th e calculations have been carried out using a model with nine electroni c target states and configuration-interaction representations of the t arget wavefunctions. Ten scattering symmetries with a fixed internucle ar separation of R = 2.3 a(0) and the vibrational averaged resonance s ymmetries (2) Pi(u) and (4) Sigma(u)(-) have been used for calculating the cross sections. The current experimental data were derived using standard crossed-beam techniques. Both the calculation and measurement s were conducted to provide further insight into the worrying discrepa ncies between the differential cross sections of various experimental groups for low-energy elastic electron scattering from O-2, as were re cently highlighted in the literature.