Regular Article – Experimental Physics
-defined isochronous mass spectrometry and mass measurements of Ni fragments
CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
2 School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 100049, Beijing, China
3 GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291, Darmstadt, Germany
4 Department of Physics, Saitama University, 338-8570, Saitama, Japan
5 School of Nuclear Science and Engineering, East China University of Technology, 330013, Nanchang, China
Accepted: 20 January 2023
Published online: 14 February 2023
A novel isochronous mass spectrometry, termed as -defined IMS, has been established at the experimental cooler-storage ring CSRe in Lanzhou. Its potential has been studied through high precision mass measurements of Ni projectile fragments. Two time-of-flight detectors were installed in one of the straight sections of CSRe, thus enabling simultaneous measurements of the velocity and the revolution time of each stored short-lived ion. This allows for calculating the magnetic rigidity and the orbit length C of each ion. The accurate function has been constructed, which is a universal calibration curve used to deduce the masses of the stored nuclides. The sensitivity to single stored ions, fast measurement time, and background-free characteristics of the method are ideally suited to address nuclides with very short lifetimes and smallest production yields. In the limiting case of just a single particle, the achieved mass resolving power allows one to determine its mass-over-charge ratio m/q with a remarkable precision of merely keV. Masses of fp-shell nuclides are re-determined with high accuracy, and the validity of the isospin multiplet mass equation is tested up to the heaviest isospin quartet with . The new masses are also used to investigate the mirror symmetry of empirical residual proton-neutron interactions.
© The Author(s) 2023
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