Precision experiments with stored exotic nuclides for nuclear structure and astrophysics (Yuri A Litvinov (GSI))

Wednesday 10 Jul 2013, 15:40 → 16:40 Asia/Tokyo

RIBF Bldg. Room 203 (RIKEN Wako)

Place: RIBF building room 203 Title : Precision experiments with stored exotic nuclides for nuclear structure and astrophysics Speaker : Dr. Yuri A Litvinov (GSI) Abstract : Heavy-ion storage rings coupled to radioactive ion beam facilities offer unique capabilities for nuclear physics experiments. There are presently two operational facilities, namely the Experimental Storage Ring (ESR) at GSI in Darmstadt, Germany and the experimental Cooler-Storage Ring (CSRe) at IMP in Lanzhou, P. R. China, at which several research programs are being pursued. Well-established are direct mass measurements of short-lived nuclei. A characteristic property of the storage ring mass spectrometry is that masses of several tens of isotopes can be measured in a single experiment. Nuclei with half-lives as short as a few ten microseconds can be addressed, which, together with the sensitivity to single stored ions, allows addressing the most exotic nuclear species. Owing to the ultra-high vacuum conditions, high atomic charge states of stored ions can be preserved for extended periods of time, which is an indispensable prerequisite for decay studies of highly-charged ions. One prominent example is the bound-state beta decay, which was discovered in the ESR. In the recent years, a lot of attention has been given to electron-capture decay of few-electron ions. Storage rings are being considered for nuclear reaction studies. Compared to external target experiments, here a thin windowless internal gas target combined with high revolution frequencies of stored ions offer advantageous conditions for a range of experiments. For instance proton capture reaction on slowed-down to 10 MeV/u fully ionised 95Rh was measured. After this proof-of-principle experiment, a series of measurements is envisioned on p- and alpha-capture reactions in the Gamow window of the astrophysical p-process. The first in-ring transfer reaction 20Ne(p,d)19Ne has been successfully studied in the ESR in October 2012. Furthermore, at the time of submission of the present abstract, proton scattering on stored 58Ni and 56Ni beams is being investigated at the ESR as a part of the commissioning program of the EXL experiment. Research programs at storage rings have proven their high discovery potential, which is clearly indicated by a number of new storage ring projects started around the world: TSR@ISOLDE at CERN, CRYRING@ESR at GSI, RI-RING in RIKEN as well as new storage ring complexes at FAIR in Germany and at HIAF in China. In this presentation a review will be given on the present nuclear physics research programs at storage rings. Examples of recent results will be presented as well as future perspectives will be discussed. Furthermore, plans for new storage ring projects will be outlined.