Precision isochronous mass measurements at the storage ring CSRe in Lanzhou

摘要

Direct mass measurements of ~(78)Kr projectile fragments have been performed in the recently commissioned storage ring CSRe employing the isochronous mass spectrometry method. A new data-analysis technique has been developed to correct the drifts in the revolution frequencies caused by instabilities of the magnetic fields in the CSRe, thus yielding a mass resolving power of R = m/△m≈ 1.7 × 10~5 (sigma). Masses for ~(45)v, ~(47)Cr,~(49)Mn and ~(51)Fe nuclei are determined with a relative mass precision of δm/m ≈2× 10~(-7) (sigma) which is an improvement by a factor of ～ 2 compared to the literature values.