Author/Authors :
F. Montes، نويسنده , , H. Schatz، نويسنده , , A. Aprahamian، نويسنده , , O. Arndt، نويسنده , , A. Estrade، نويسنده , , K.-L. Kratz، نويسنده , , S.N Liddick، نويسنده , , P.F. Mantica، نويسنده , , W.F Mueller، نويسنده , , P. Hosmer، نويسنده , , A.C Morton، نويسنده , , M. Ouellette، نويسنده , , CDR Joseph E. Pellegrini، نويسنده , , B. Pfeiffer، نويسنده , , P. Reeder، نويسنده , , P. Santi ، نويسنده , , A. Stolz، نويسنده , , B.E. Tomlin، نويسنده , , W.B. Walters، نويسنده , , A. Wohr، نويسنده , , et al.، نويسنده ,
Abstract :
New half-lives for neutron-rich ruthenium, rhodium and palladium isotopes close to the r-process path along the N=82 closed shell have been measured at the National Superconducting Cyclotron Laboratory at Michigan State University. The studied isotopes are close to the critical A=118-126 mass region in the astrophysical r-process, where incorrect nuclear structure development towards the shell closure may have the most pronounced effect on the abundances of elements produced. Neutron-rich nuclei were produced by fragmentation of a 120-MeV per nucleon 136Xe beam on Be and were separated by the A1900 fragment separator. The nuclei of interest were implanted into a double-sided Si strip detector at the center of the MSU β counting system. Charge states and fully- stripped isotopes were distinguished by a measurement of the total kinetic energy of each implant. Our measured half-lives will provide first clues on whether our understanding of nuclear structure evolution in this mass region is correct.
