Mass measurements near the $r$-process path using the Canadian Penning   Trap mass spectrometer
  The masses of 40 neutron-rich nuclides from Z = 51 to 64 were measured at an average precision of $\delta m/m= 10^{-7}$ using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. The measurements, of fission fragments from a $^{252}$Cf spontaneous fission source in a helium gas catcher, approach the predicted path of the astrophysical $r$ process. Where overlap exists, this data set is largely consistent with previous measurements from Penning traps, storage rings, and reaction energetics, but large systematic deviations are apparent in $\beta$-endpoint measurements. Differences in mass excess from the 2003 Atomic Mass Evaluation of up to 400 keV are seen, as well as systematic disagreement with various mass models. 
J. Van Schelt, D. Lascar, G. Savard, J. A. Clark, S. Caldwell, A.   Chaudhuri, J. Fallis, J. P. Greene, A. F. Levand, G. Li,...
nucl-ex