Electron scattering by ytterbium: II. Excitation of the 4f14(6s6p 3P1, 5d6s 1D2 and 6s7p 1P1) and 4f135d6s2 (7/2, 5/2)1 states

Abstract

Differential cross sections (DCSs) for electron-impact excitation of the 4f146s6p3P1 (2.231 eV) state of ytterbium have been determined experimentally at incident electron energies, E0 = 10, 20 and 40 eV, and scattering angles (θ) from 2° to 150° (at 10 eV from 10°). Also, DCSs for the 4f145d6s 1D2 (3.432 eV) and 4f135d6s2 (7/2, 5/2)1 (3.578 eV) states at E0 = 10 and 20 eV, and the 4f146s7p 1P1 (5.029 eV) state at 20 and 40 eV have been measured. These measurements were performed at θ between 10° and 150° for the 4f145d6s 1D2 and 4f135d6s2 (7/2, 5/2)1 states, and between 2° and 150° for the 4f146s7p 1P1 state. The inelastic-to-reference inelastic (the 4f146s6p 1P1 resonance state) intensity ratios were obtained from energy-loss spectra recorded with overall energy resolution of 65 meV (FWHM) and angular resolution of 1.5°. Using these ratios and DCSs for the reference state (Predojević et al 2005 J. Phys. B: At. Mol. Opt. Phys. 38 1329) the absolute inelastic DCSs were determined. In this way the obtained DCSs were extrapolated to 0° and 180° and numerically integrated to yield integral, momentum transfer and viscosity cross sections. Our results are compared with available calculated values and experimental data.