Electron affinity of Bi using infrared laser photodetachment threshold spectroscopy

We report the results of high-resolution infrared laser photodetachment threshold experiments on the negative ion of bismuth. The hyperfine structure of the neutral and negative-ion ground states are included in the threshold model. The electron affinity of 209Bi is determined to be 7600.66(10) cm-1 [942.362(13) meV].