The electron affinity of tungsten

The electron affinity of tungsten has been measured using laser photodetachment threshold spectroscopy in a collinear geometry. The electron affinity was determined to 6583.6(6) cm(-1) by observing the onset of the process when W- ions in the 5d(5)6s(2)(6)S(5/2) ground state are photodetached producing neutral W atoms in the 5d(4)6s(2) D-5(0) ground state. The measured value is in agreement with previous measurements and improves the accuracy by almost two orders of magnitude. Further, a photodetachment signal below the ground state photodetachment threshold was found, which indicates the existence of a bound excited state in W-.