ABSORPTION CROSS-SECTION MEASUREMENTS ON VACUUM ULTRA-VIOLET SPECTRUM OF ZINC VAPOUR

Absolute cross sections for photoionization and autoionization processes are reported from the ionization threshold at 1320 Angstrom to 750 Angstrom. The value of the photoionization cross section at the ionization threshold is 1·1 ± 0·2 Mbn falling to a near zero minimum in the neighbourhood of 1200 Angstrom. At shorter wavelengths, the spectrum is completely dominated by autoionization transitions. The oscillator strengths and half-widths of the absorption features are reported, and configuration interaction effects discussed, in connection with the observed cross-section profiles of the 4s2 1S0 -> 3d 94s24p 1P1, 3P 1, 3D1 multiplet.