Generalized oscillator strength for the lyman-birge-hopfield band in molecular nitrogen

The generalized oscillator strength for the dipole-forbidden quadrupole-allowed transition X 1? g + ->a 1? g in molecular nitrogen has been determined from the electron inelastic differential cross-section measured at 1000 eV incident energy and scattering angles as large as 50°. The relative cross-section has been brought to the absolute scale through normalization to the elastic cross-section. The total excitation cross-section and the electric-quadrupole excitation probability are also derived. A description of the apparatus, which is a crossed-beam, intermediate-energy (50{curly logical or}4000) eV, coincidence electron spectrometer, is presented.