Electron scattering by trimethylene oxide, c-(CH2)3O, molecules

Abstract

Electron-scattering cross sections have been determined for trimethylene oxide, cyclic (CH(2))(3)O molecule, both experimentally and theoretically. The absolute total cross section (TCS) has been measured over energies from 1 to 400 eV using a linear electron-transmission method. The obtained TCS generally decreases with rising energy, except for the 3-10 eV range, where some resonantlike structures are discernible. Integral elastic cross section (ECS) and ionization cross section (ICS) have been also calculated up to 3 keV in the additivity rule approximation and the binary-encounter-Bethe approach, respectively. Their sum, ECS+ICS, is in a good agreement with the measured TCS. Comparison of the TCS energy dependence for trimethylene oxide with that for its isomeric open-chain counterpart--acetone, (CH(3))(2)CO, has also been made. Moreover, examination of experimental TCSs for the cyclic (CH(2))(n)O, n=2-4, ether series reveals that the intermediate-energy molecular TCSs for members of that family can be nicely represented as a sum of the effective TCSs for particular constituents of the molecule, i.e., methylene groups and oxygen atom. Finally, based on these partial TCSs, the TCS for the c-(CH(2))(5)O--the next member of the series--has been determined and compared with the respective ECS+ICS values computed here for this compound.