ELASTIC AND VIBRATIONAL-EXCITATION CROSS-SECTIONS FOR ELECTRON COLLISIONS WITH PROPANE

Absolute, elastic differential cross sections (DCS) for electron-propa ne collisions have been measured over a range of scattering angles fro m 10-degrees to 130-degrees and at incident kinetic energies from 2 to 100 eV. The angular distributions were extrapolated to 0-degrees and 180-degrees by a nonlinear phase shift fit and integrated numerically to obtain the integral clastic and momentum transfer cross sections. T he observed Dcs agree approximately with a continuum multiple scatteri ng calculation that uses only local potentials and also with a multich annel Schwinger variational calculation. The vibrationally inelastic D CS reveal a shape resonance with a peak at 7.5 eV that is characterist ic of trapping by valence orbitals with C-H antibonding character and is identical with peaks encountered in electron-methane and electron-e thane scattering.