Abstract
Background: The previously reported levels assigned to have recently been called into question regarding their mass assignment.
Purpose: We clarify the above questioned level assignments by measuring transitions tagged with and in an in-beam experiment in addition to the measurements from spontaneous fission (SF) and establish new spectroscopic information from to in the Pr isotopic chain.
Methods: The isotopic chain has been studied from the spontaneous fission of by using Gammasphere and also from the measurement of the prompt rays in coincidence with isotopically identified fission fragments using VAMOS++ and EXOGAM at Grand Accelerateur National d'Ions Lourds (GANIL). The latter were produced using beams on a target at energies around the Coulomb barrier. The data from (SF) and those from the GANIL in-beam - and -gated spectra were combined to unambiguously assign the various transitions and levels in and other isotopes.
Results: A band of 3 new transitions added to the known level in , 9 new transitions in two new bands in , 6 new transitions in a new level scheme for , two new bands with 17 new transitions in , and two new bands with 11 new transitions in were identified by using and coincidences and and -gated spectra. The transitions and levels previously assigned to have been confirmed by the -gated spectra. Small changes have been made to their original level schemes. The transitions previously assigned to are now assigned to on the basis of the -gated spectra. Two new bands with 20 new transitions in and one new band with 7 new transitions in are identified from the coincidence spectra and the -gated spectrum. In addition, new rays are also reported in .
Conclusions: New levels of have been established, reliable mass assignments of the levels in have been given in the present work, and new transitions have been identified in showing the new avenues that are opened by combining the two experimental approaches.
22 More- Received 8 July 2015
DOI:https://doi.org/10.1103/PhysRevC.92.034317
©2015 American Physical Society