Eur. Phys. J. A (2010) 45: 153-158
https://doi.org/10.1140/epja/i2010-11003-4

Regular Article - Experimental Physics

Spin-alignment and g-factor measurement of the = 12⁺ isomer in ¹⁹²Pb produced in the relativistic-energy fragmentation of a ²³⁸U beam

¹ H. Niewodniczański Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342, Kraków, Poland
² GSI, Planckstrasse 1, D-64291, Darmstadt, Germany
³ K.U. Leuven, Instituut voor Kern- en Stralingsfysica, B-3001, Leuven, Belgium
⁴ Faculty of Physics, University of Sofia “St. Kl. Ohridski”, BG-1164, Sofia, Bulgaria
⁵ Dipartamento di Fisica, Università degli Studi di Camerino and INFN sez. Perugia, I-62032, Camerino, Italy
⁶ Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
⁷ INFN Sez. di Milano, Via Celoria 16, 20133, Milano, Italy
⁸ Università degli Studi di Milano, I-20133, Milano, Italy
⁹ Weizman Institute of Science, 76100, Rehovot, Israel
¹⁰ Fraunhofer INT, D 53879, Euskirchen, Germany
¹¹ CEA, DAM, DIF, F-91297, Arpajon Cedex, France
¹² CSNSM, Université Paris-Sud 11, CNRS/IN2P3, F-91405, Orsay-Campus, France
¹³ Department of Physics, Lund University, S-22100, Lund, Sweden
¹⁴ Institut für Kernphysik, Universität zu Köln, D-50937, Köln, Germany
¹⁵ National Institute for Physics and Nuclear Engineering, RO-76900, Bucharest, Romania
¹⁶ Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
¹⁷ Jagiellonian University, Kraków, Poland
¹⁸ University of Warsaw, PL-00681, Warsaw, Poland
¹⁹ Department of Physics, University of Surrey, Guildford, GU2 7XH, UK
²⁰ Institut Laue Langevin, Grenoble, France
²¹ Institute of Physics PAN, Warsaw, Poland

^* e-mail: maria.kmiecik@ifj.edu.pl

Received: 30 December 2009
Revised: 27 April 2010
Accepted: 11 June 2010
Published online: 8 July 2010

Abstract

The feasibility of measuring g -factors using the TDPAD method applied to high-energy, heavy fragmentation products is explored. The 2623keV isomer in ¹⁹²Pb with = 1.57 μs has been produced using the fragmentation of a 1A GeV ²³⁸U beam. The results presented demonstrate for the first time that such heavy nuclei produced in a fragmentation reaction with a relativistic beam are sufficiently well spin-aligned. Moreover, the rather large value of the alignment, 28(10)% of the maximum possible, is preserved during the separation process allowing the determination of magnetic moments. The measured values of the lifetime, = 1.54(9) μs, and the g -factor, g = - 0.175(20) , agree with the results of previous investigations using fusion-evaporation reactions.