Spectroscopy around N = 126 nuclei produced by multi-nucleon transfer reaction

The $\beta $-decay properties of the neutron-rich isotopes with neutron number N = 126 are supposed to play a critical role for better understanding of r-process. We will study $\beta $-decay properties and nuclear structures around N = 126 nuclei by $\beta $-decay and laser spectroscopy. As the first step, we are going to produce $^{202}$Os (Z = 76, N = 126), which has not been produced in any other facilities, by using the multi-nucleon transfer reactions in $^{136}$Xe (stable beam) + $^{198}$Pt (target) collision. The Pt target is used as the window of the gas catcher for collecting all reaction products by the collision, from which the $^{202}$Os will be extracted as singly-charged ions by laser resonance ionization and transported to a detection station after being mass-separated for the spectroscopy.