A study of resonance structures in elastic electron scattering by carbon monoxide and molecular nitrogen in the backward direction

Resonance structures corresponding to the (3sσ)2 2Σ+ state in carbon monoxide at 10.044 eV and the (3sσg)2 2Σg+ state in nitrogen at 11.499 eV have been studied in elastic electron scattering over the range of scattering angle from 95° to 180°. A new magnetic angle-changing technique has been used in the measurements, which has enabled the first observation of these resonance structures at and close to 180°. The width of the 2Σ+ resonance in carbon monoxide has been determined to be 42±3 meV.