K.R. Lykke, K.K. Murray, W.C. Lineberger, “Threshold photodetachment of H−,” Phys. Rev. A. 43 (1991) 6104–6107. doi:10.1103/PhysRevA.43.6104.
The electron affinities of atomic hydrogen and deuterium have been determined by tunable-laser threshold-photodetachment spectroscopy: the electron affinities of H (F=0) and D (F=1/2) are 6082.99±0.15 and 6086.2±0.6 cm−1, respectively. The value for H is a 20-fold improvement over previous experimental determinations.