Vv. Petrunin et al., STRUCTURAL-PROPERTIES OF THE NEGATIVE CALCIUM-ION - BINDING-ENERGIES AND FINE-STRUCTURE SPLITTING, Physical review letters, 76(5), 1996, pp. 744-747
The binding energies of the 4s(2)4p(2)P ground state in Ca- have been
determined by means of state-selective photoionization of Ca atoms pro
duced in s-wave photodetachment to be 24.55 +/- 0.10 meV for the J = 1
/2 and 19.73 +/- 0.10 meV for the J = 3/2 component. The sensitivity o
f the detection technique applied has also made it possible to disprov
e previous claims for the observation of a metastable 4s4p(24)P State
in Ca-.