ELECTRON-AFFINITY OF STRONTIUM

We have observed a threshold in the electron photodetachment cross sec tion of Sr-88(-) ions at a photon energy h nu = 1.820 eV and assign it to a p-wave transition from the 5s(2)5p P-2 ground state in Sr- to th e 5s5p P-3 State in neutral Sr. The measurement was made with a new te chnique combining the tunable laser photodetachment threshold method w ith accelerator mass spectrometry. We determine for the first time the electron affinity of Sr to be 48 +/- 6 meV, much smaller than predict ed in recent calculations. The P-2(1/2)-P-2(3/2) fine splitting of the Sr- ground state is estimated to be 26 +/- 8 meV.