ABSOLUTE OPTICAL OSCILLATOR-STRENGTHS FOR THE ELECTRONIC EXCITATION OF ATOMS AT HIGH-RESOLUTION .2. THE PHOTOABSORPTION OF NEON

A recently developed high-resolution dipole (e,e) method [W. F. Chan, G. Cooper, and C. E. Brion, Phys. Rev. A 44, 186 (1991)] for the measurement of absolute optical oscillator strengths (cross sections) for electronic excitation of free atoms and molecules has now been applied to photoabsorption and photoionization processes for neon in the energy range 16-250 eV. The absolute scale is obtained by Thomas-Reiche-Kuhn (TRK) sum-rule normalization of the Bethe-Born converted electron-energy-loss spectrum. The measured absolute photoabsorption oscillator strengths for discrete electronic transitions of neon from the ground state to the 2s22p5ns and 2s22p5nd(2P3/2,1/2) manifolds are compared where previously reported experimental data are available. Measurements of the absolute optical strength in the photoionization continuum up to 250 eV are compared with other experimental and theoretical data. Absolute optical oscillator strengths in the 40-55-eV region of the 2s2p6np and 2s22p(4)3lnl' autoionizing resonances are also reported.