Spectroscopy of neutron-rich P 34,35,36,37,38 populated in binary grazing reactions

R. Chapman et al.; 17 pags.; 18 figs.; 1 tab.; PACS number(s): 23.20.Lv, 25.70.Lm, 27.30.+t
© 2015 American Physical Society. The neutron-rich nuclei P34,35,36,37,38 were populated in binary grazing reactions initiated by a beam of S36 ions at 215 MeV incident on a thin Pb208 target. The combination of the PRISMA magnetic spectrometer and the CLARA array of escape-suppressed Ge detectors was used to detect γ rays in coincidence with projectile-like nuclear species. Further evidence to support the observed γ decay of excited states of the populated phosphorus isotopes is provided by γ-γ coincidence measurements based on the results of an earlier thick-target deep-inelastic experiment. Level schemes for P34,35,36,37,38 are presented and discussed within the context of state-of-the-art shell-model calculations. In particular, new spin and parity assignments are proposed for a number of excited states of P36. The evolution with neutron number of the energy difference of the low-lying Jπ=3/2+ and 1/2+ states in the odd-A isotopes of phosphorus, as well as the relationship to nuclear collectivity, is discussed. The evolution with neutron number of the shell-model wave functions of the first Jπ=1/2+, 3/2+, and 5/2+ states of the odd-A phosphorus isotopes and of the first Jπ=3-, 4-, and 5- states of the even-A isotopes is also explored.
We would like to thank the technical staff of the INFN Legnaro National Laboratory for their support during this experiment. This work was supported by the EPSRC (U.K). Four of us (A.H., M.B., K.L.K., and A.P.) would like to acknowledge the receipt of financial support from EPSRC during the course of this work. A.J. would like to acknowledge support from the Spanish Ministerio de Ciencia e Innovacion´ under Contract No. FPA2011-29854-C04. Z.D. acknowledges the financial support from OTKA Grant No. K100835.