Iwao Fujita

Optical excitation function of CO by electron impact near threshold

Abstract The emission spectrum for the b 3 Σ + → a 3 Π r , d 3 Δ i → a 3 Π r , and B 1 Σ + → A 1 Π transitions of CO was observed in low energy electron impact and the excitation function on CO(b 3 Σ + ) was examined near the excitation threshold. The strong and weak resonance peaks near the threshold were assigned to the core-excited shape resonances at 10.39 and 10.7 eV, respectively, which have been observed in an electron scattering experiment.

Formation and quenching of NH fragments in excited states by high energy electron irradiation of helium-ammonia gas mixture

Abstract A gas mixture of helium and ammonia was irradiated with an electron beam from a Van de Graaff accelerator and emission intensities from excited NH fragments were measured as a function of pressure, concentration of ammonia, and the amounts of additives. The energy transfer process is discussed on the basis of the experimental results and kinetic analysis.

Formation and quenching of CO and CO ion in excited states by high energy electron irradiation of heliumcarbon monoxide gas mixture

Abstract Gas mixture of helium and carbon monoxide was irradiated with electron beam from a Van de Graaff accelerator and emission intensities from excited CO and CO ion were measured as a function of pressure, concentration of carbon monoxide in wide ranges. The results are fitted with kinetic analytical formulae derived from simple competition reactions involving energy transfer process assuming steady state concentrations for intermediates, and reasonable agreements were obtained between the experimental results and those predicted in the range of reaction conditions studied in this work.

Photo-emission from excited CF2 radical by high energy electron irradiation of chlorofluorocarbons

Chlorofluorocarbons CCl2F2 (CFC-12) and CHClF2 (HCFC-22) in the gas phase were irradiated with high energy electron beam from a Van de Graaff accelerator and emission intensity of the excited CF2 (A1B1) radical was measured as a function of sample gas. The result shows that a formation path via a precursor exists besides of the direct formation by electron impact. Experiments were also made for mixtures of chlorofluorocarbons and helium or argon.

Automatic analytical differentiation for nonlinear least-squares calculations

Abstract A program package is described for making nonlinear least-squares calculations on a personal computer. The numerical calculation is performed after the given expression has been analytically differentiated with respect to the nonlinear parameters; the differentiation is performed automatically. Another feature of the program is that estimation of the initial values of the parameters has been partially automated.

An Attempt to Predict Mass Spectra of n-Propylamine

MOT (Molecular orbital theory for fragmentation) hitherto proposed is extended to be able to predict semiquantitatively all fragments and molecular ions by introducing a slow unimolecular type of fragmentation in addition to the fast type hitherto assumed. Ratio of the slow and fast fragmentation is determinable automatically on the basis of the electron densities allotted to the HOMO at the lone pair electrons and skeletal bonds, respectively. The calculated intensities of main peaks in the mass spectra showed a good coincidence with the experimental ones, and their changes with ionizing voltage could be also explained to some extent.