First on-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region produced in fusion-evaporation reactions were determined with relative uncertainties of about 7⋅10−8, nine of them for the first time. Four nuclides (144,145Ho and 147,148Tm) were found to be proton-unbound. The implication of the results on the location of the proton drip-line is discussed by analyzing the one-proton separation energies.
@article{arxiv.nucl-ex/0701030,
title = {Direct mass measurements beyond the proton drip-line},
author = {C. Rauth and D. Ackermann and K. Blaum and M. Block and A. Chaudhuri and S. Eliseev and R. Ferrer and D. Habs and F. Herfurth and F. P. Hessberger and S. Hofmann and H. -J. Kluge and G. Maero and A. Martin and G. Marx and M. Mukherjee and J. B. Neumayr and W. R. Plass and W. Quint and S. Rahaman and D. Rodriguez and C. Scheidenberger and L. Schweikhard and P. G. Thirolf and G. Vorobjev and C. Weber and Z. Di},
journal= {arXiv preprint arXiv:nucl-ex/0701030},
year = {2008}
}