139La-Lanthanum
139La has 57 protons and 82 neutrons.
139La is a stable isotope.
The mass excess of 139La is -87222.381 with an uncertainty of ±0.607.
The mass was measured using a Penning Trap and Nuclear Physics and the related equations include:
Influence Equations
94.5% 139La-136Xe1.022 1
5.5% 139La(n, γ)140La 2
Reference
1. R. Sandler, G. Bollen, J. Dissanayake, M. Eibach, K. Gulyuz, A. Hamaker, C. Izzo, X. Mougeot, D. Puentes, F.G.A. Quarati, M. Redshaw, R. Ringle, I. Yandow (2019)
Direct determination of the 138La β-decay Q value using Penning trap mass spectrometry Physical Review C 100(1)
https://journals.aps.org/prc/abstract/10.1103/PhysRevC.100.014308
2. E.T. Jurney, R.K. Sheline, E.B. Shera, H.R. Koch, B.P.K. Maier, U. Gruber, H. Baader, D. Breitig, O.W.B. Schult (1970)
Study of the Levels in 140La Using the 139La(n, γ)140La Reaction Physical Review C 2(6)
https://journals.aps.org/prc/abstract/10.1103/PhysRevC.2.2323