Abstract
Resonances in the total cross section in the energy range 50-300 meV were studied with a high-resolution ( meV) electron time-of-flight spectrometer. Each vibrational resonance was found to have a well-resolved doublet structure, which has not previously been observed, and which is due to spin-orbit coupling in the ground state of . The spin-orbit coupling constant of was measured to be , in agreement with theoretical estimates. On an energy scale established from the measured electron flight times, the energy of the center of the resonance was measured to be 91 ± 5 meV. This value is in agreement with a recent photodetachment measurement of the electron affinity of , and with a previously observed accidental coincidence between the level of and the level of . The electron time-of-flight spectrometer is described in detail.
- Received 4 October 1973
DOI:https://doi.org/10.1103/PhysRevA.9.1592
©1974 American Physical Society