Electron affinities of O-16, O-17, O-18, the fine structure of O-16(-), and the hyperfine structure of O-17(-) - art. no. 052504

Photodetachment microscopy has been used in a double-pass, field-collinear scheme in order to measure the electron affinity of atomic oxygen. As an il lustration of the sensitivity of the method, electron images could be recor ded even from the rarest O-17(-) ion. Analysis of photodetachment images re corded with this odd isotope, however, requires that one knows the unresolv ed hyperfine structures of the ground states of both the neutral atom O-17 and the negative ion. Calculation of the hyperfine structure of O-17(-) was achieved, which permitted to add the electron affinity of O-17 to the seri es of the measured electron affinities of oxygen isotopes. The anomalous is otope shift of these electron affinities is finally compared with ab initio calculations.