Neutron drip-line topography

For heavy elements, the neutron drip-line will (most likely) never be reached by radioactive beam facilities. However, the location of the neutron drip-line is of great importance for modeling the rapid neutron-capture process [1]. Therefore, the development of microscopic mass models is the only hope in our quest to understand how most of the elements of our world were fabricated. Confidence in drip-line predictions of such models requires their comparison with new mass data for nuclides far from stability. In this contribution, we combine theory and experiment using results that are state of the art: The latest mass measurements from the Penning-trap spectrometer ISOLTRAP at CERN-ISOLDE [2] are used to confront the predictions of the latest Skyrme-Hartree-Fock-Bogoliubov (HFB) microscopic mass models [3,4]. Two chains of isotopes are used with new masses particularly far from what was known previously: 223-229Rn [5] and 144-147Xe [6]. The sensitivity of the HFB fits to the new data is used to re-evaluate parameters of the Skyrme interaction used in these models. In addition, we compare the new data to predictions of other types of mass models and the extrapolative behavior of the various models is analyzed to highlight topographical trends at the shores of the ethereal nuclear chart.(author)