An Experimental Plan to Study Beta-decay Properties on N = 126 Waiting-Point Nuclei in the r-process

The β-decay properties of the neutron-rich isotopes with neutron number N = 126, out of reach by any reaction well established so far, are very interesting from the astrophysical point of view. We will propose β-decay lifetime measurements with a new isotope separation system, which is supposed to separate a single species of the radioactive nuclei among target-like fragments produced via multi-nucleon transfer reactions in binary heavy ion collisions, by using a gas catcher cell combined with laser resonance ionization technique. The present proposal aims to measure β-decay properties of several nuclei around A∼200 with N = 126 and nearby nuclei by using a stable 136Xe beam on a 198Pt target.