Abstract
High-precision mass measurements of proton-rich isotopes in the range of were performed using the novel technique of Schottky spectrometry. Projectile fragments produced by Bi ions at 930A MeV were separated with the magnetic spectrometer FRS and stored and cooled in the experimental storage ring (ESR). A typical mass resolving power of 350 000 and a precision of 100 keV were achieved in the region . Masses of members of chains linked by precise values but not yet connected to the known masses were determined. In this way it is concluded that Fr and At are proton unbound.
- Received 23 September 1996
DOI:https://doi.org/10.1103/PhysRevLett.78.4701
©1997 American Physical Society