Journal of Chemical Physics, Vol.116, No.10, 4023-4029, 2002
Single to triple ionization of propane due to electron impact: Cross sections for the different dissociation channels
Electron impact single to triple ionization and subsequent dissociation of propane have been studied at an electron energy of 200 eV using a covariance mapping technique employing a focusing time-of-flight mass spectrometer. The dissociation channels of up to triply ionized propane have been identified and the corresponding absolute cross sections for the different dissociation channels have been obtained. Results show that 88% of the singly ionized propane molecules are unstable and dissociate through more than 20 channels, among which 50% of the C3H8+ ions dissociate into C2H5+ or C2H4+. All the doubly ionized propane molecules are unstable and dissociate through more than 80 channels, among which 97% of the C3H82+ ions dissociate into ion pairs. The major dissociation channels for C3H82+ are C2H3++CH3+, H++H+, and C2H4++CH3+, while the major ionic products from the dissociation of C3H82+ are H+, CH3+, and C2H3+.