Spin-alignment in abrasion-fission reaction – g-factor measurement of isomeric states

J.M. Daugas , F. Boulay , G.S. Simpson (1) , Y. Ichikawa , D.S. Ahn , D.L. Balabanski , T. Egami , T. Fujita , N. Fukuda , C. Funayama , T. Furukawa , G. Georgiev , A. Gladkov , M. Hass , K. Imamura , N. Inabe , Y. Ishibashi , T. Kawaguchi , T. Kawamura , W. Kim , Y. Kobayashi , S. Kojima , A. Kusoglu , S. Momiyama , I. Mukul , M. Niikura , H. Nishibata , T. Nishizaka , A. Odahara , Y. Ohtomo , D. Ralet , T. Sato , Y. Shimizu , T. Shimoda , T. Sumikama , H. Suzuki , H. Takeda , L.C. Tao , Y. Togano , D. Tominaga , H. Ueno , H. Yamazaki , X.F. Yang

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie

The spin-alignment of fragments produced in spontaneous and neutroninduced fission reactions is found to be up to 40%. This amount of spin-alignment allows the measurement of gyromagnetic factors of s isomeric states using the well known TDPAD method. This observable is a very sensitive probe of the singleparticle structure of nuclear states and frequently allows one to determine the valence nucleon configuration. Isomers produced by spontaneous fission are difficult to measure due to their low production rates and the ones produced by neutroninduced fission and selected in a spectrometer could not be measured because one needs to have fully stripped isotopes to preserve the spin-alignment in the vacuum. The measurement performed at the RIKEN Nishina Center accelerator using the abrasion-fission reaction of a 238U80+ beam at 345 MeV/u energy on the N=59 99mZr and 98mY will be presented. The obtained results show the opportunity to perform gyromagnetic factors measurement of neutron-rich s-isomers produced by the abrasion-fission reaction.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

J.M. Daugas, F. Boulay, G.S. Simpson, Y. Ichikawa, D.S. Ahn, et al.. Spin-alignment in abrasion-fission reaction – g-factor measurement of isomeric states. 6th Workshop on Nuclear Fission and Spectroscopy of Neutron-Rich Nuclei (FISSION 2017), Mar 2017, Chamrousse, France. ⟨in2p3-01503647⟩