Direct mass measurements of neutron-deficient ¹⁵²Sm projectile fragments at FRS-ESR facility

Direct mass measurement was performed on neutron-deficient ¹⁵²Sm projectile fragments at the FRS-ESR facility at GSI, employing the time-resolved Schottky Mass Spectrometry method. Exotic nuclei were produced via fragmentation of relativistic ¹⁵²Sm projectiles in a thick beryllium target. The reaction products were separated in-flight with the fragment separator FRS, and injected into the storage-cooler ring ESR. 311 different nuclides were identified by means of their revolution frequency spectra. Masses for 14 nuclides (^116,118Ba, ^122,123La, ^124,125Ce, ^123,127Pr, ¹²⁹Nd, ^130,132Pm, ¹³⁴Sm, ¹³⁷Eu, ¹³⁸Gd) have been determined for the first time. The new masses allow us to uncover a part of the previously unknown mass surface and will be used to constrain nuclear mass models. The data analysis is in progress.