Increased lifetime of hydrogen-like $^{192m}Os$ observed in the ESR

A. Akber1, M.W. Reed1, P.M. Walker2, I.J. Cullen2, Yu.A. Litvinov3,4,5, K. Blaum3,5, F. Bosch4, C. Brandau4,6, J.J. Carroll7, D.M. Cullen8, A.Y. Deo2, B. Detwiler9, C. Dimopoulou4, G.D. Dracoulis1, F. Farinon4, H. Geissel4,10, E. Haettner10, M. Heil4, R.S. Kempley2, T. Kibédi1, R. Knöbel4,10, C. Kozhuharov4, J. Kurcewicz4,11, N. Kuzminchuk4,10, G.J Lane1, S. Litvinov4, Z. Liu12,13, R. Mao13, C. Nociforo4, F. Nolden4, W.R. Plass4,10, A. Prochazka4, C. Scheidenberger4,10, D. Shubina3,5, M. Steck4, Th. Stöhlker4,14,15, B. Sun4, T.P.D. Swan2, G. Trees9, H. Weick4, N. Winckler3,4, M. Winkler4, P.J. Woods12, and T. Yamaguchi16 1Department of Nuclear Physics, R.S.P.E., Australian National University, Canberra ACT 0200, Australia; 2Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom; 3Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany; 4GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany; 5Physikalisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany; 6ExtreMe Matter Institute EMMI, 64291 Darmstadt, Germany; 7US Army Research Laboratory, 2800 Powder Mill,Road, Adelphi MD, USA; 8Schuster Laboratory, University of Manchester, Manchester M13 9PL, United Kingdom; 9Youngstown State University, One University Plaza, Youngstown, Ohio 44555, USA; 10II Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen, Germany; 11CERN, 1211 Geneva 23, Switzerland; 12School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom; 13Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; 14Institute of Physics, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; 15Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany; 16Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan Using the Experimental Storage Ring (ESR) it is possible to distinguish between charge states of an isotope with sensitivity down to single ions [1]. Projectile fragmentation of a Au beam (478-492 A·MeV) with a Be target was performed and the resultant fragments were passed through the FRagment Separator [2] where isotopes of interest were separted before being injected into the ESR. The ions were cooled by electron and stochastic cooling enabling Schottky Mass Spectrometry to be used and nuclear decays within the ESR are inferred from changes in ion revolution frequency [3]. Prior studies of Os revealed an isomer with a lifetime of τneut = 8.5(14) s at 2015 keV. Three decay branches have been observed with transition energies of 47, 302, and 307 keV [4]. Neutral [5] and hydrogen-like internal conversion coefficients were calculated and indicate a decrease for all transitions (Table 1). For the 47 keV transition internal conversion in the hydrogen-like state is forbidden. An increased lifetime of τcalc = 13.0(24) s due to the reduction of internal conversion can be expected.