$$B\rho $$-defined isochronous mass spectrometry and mass measurements of $$^{58}$$Ni fragments

A novel isochronous mass spectrometry, termed as $B\rho$-defined IMS, is established at the experimental cooler-storage ring CSRe in Lanzhou. Its potential has been studied through high precision measurements of $^{58}$Ni projectile fragments. Two time-of-flight detectors were installed one straight sections CSRe, thus enabling simultaneous velocity and revolution time each stored short-lived ion. This allows for calculating magnetic rigidity $B\rho$ orbit length $C$ The accurate $B\rho(C)$ function constructed, which a universal calibration curve used to deduce masses nuclides. sensitivity single ions, quickness, background-free characteristics method are ideally suited address nuclides with very short lifetimes tiniest production yields. In limiting case just particle, attained resolving power us determine its mass-over-charge ratio $m/q$ remarkable merely $\sim5$ keV. Masses $T_z = -3/2$ fp-shell re-determined accuracy, validity isospin multiplet equation tested up heaviest quartet $A 55$. new also investigate mirror symmetry empirical residual proton-neutron interactions.