Time-separated oscillatory fields for high-precision mass measurements on short-lived Al and Ca nuclides

High-precision Penning trap mass measurements on the stable nuclide Al-27 as well as on the short-lived radionuclides Al-26 and Ca-38,Ca-39 have been performed by use of radiofrequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, recently extended to Penning trap mass measurements of radioactive isotopes. A comparison with the conventional method of a single continuous excitation demonstrates the advantage of up to ten times shorter measurements. The new mass values of Al-26,Al-27 are compared to literature values and clarify conflicting data in this mass region. In addition, the resulting mass values of the superallowed beta-emitter Ca-38 as well as of the ground state of the beta-emitter Al-26(m) confirm previous measurements. Copyright (c) EPLA, 2008.