Abstract
Due to the low cross section of -wave threshold photodetachment and the complicated electronic structures, the uncertainty of electron affinities for many transition elements still remains around 10 meV, which has not been improved for three decades. In this study, the electron affinity of Nb is measured as 917.40(6) meV or using the slow electron velocity imaging method. The accuracy was improved by a factor of more than 400 with respect to the previous measurement. Furthermore, the fine structures of were successfully resolved: 16.87(12) meV , 46.75(12) meV (), 86.85(12) meV (), and 156.00(37) meV () above the ground , respectively.
- Received 4 November 2015
DOI:https://doi.org/10.1103/PhysRevA.93.020501
©2016 American Physical Society