Radiochemical search for neutron-rich isotopes of nielsbohrium in the "1"6O + "2"5"4Es reaction

We have used on-line gas chromatography to search for new isotopes of element 107 near the deformed sub-shell at N = 162 and Z = 108. Enhanced nuclear stability is predicted for this region. "2"5"4"gEs was irradiated with "1"6O at barrier energies to minimize the fusion hindrance in the entrance channel and to reduce the excitation energy of the compound nucleus to a minimum value. For half-lives between roughly two seconds and two minutes no signal for a positive identification of a new isotope of element 107 was detected. Consequently, only an upper cross-section limit of a few nanobarns was obtained. While this cross-section limit was too high to probe the influence of the predicted enhanced nuclear ground-state stability on the survival probability in the fission/evaporation competition, a very large cross-section enhancement would have been detectable. (orig.)Available from TIB Hannover: RO 801(94-60) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

High transfer cross sections from reactions with Es

Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman