g Factor of the 7 super(-) isomer in super(126)Sn and first observation of spin-alignment in relativistic fission

• Published in: Physics letters. B Vol. 687; no. 4-5; pp. 305 - 309
• Main Authors: Ilie, G, Neyens, G, Simpson, G S, Jolie, J, Blazhev, A, Grawe, H, Lozeva, R L, Vermeulen, N, Atanasova, L, Balabanski, D L, Becker, F, Bednarczyk, P, Brandau, C, Caceres, L, Chamoli, S K, Daugas, J M, Doornenbal, P, Gerl, J, Gorska, M, Grebosz, J, Hass, M, Ionescu-Bujor, M, Jungclaus, A, Kmiecik, M, Kojouharov, I, Kurz, N, Maj, A, Mallion, S, Perru, O, Pfuetzner, M, Podolyak, Zs, Prokopowicz, W, De Rydt, M, Saito, T R, Schaffner, H, Turzo, K, Walker, J, Werner-Malento, E, Wollersheim, HJ
• Format: Journal Article
• Language: English
• Published: 19.04.2010
• Subjects: Beams (structural); Detectors; Failure; Fission; Isomers; Mathematical analysis; Nuclear fission; Nuclei
• ISSN: 0370-2693
• DOI: 10.1016/j.physletb.2010.03.033

We report on the g factor measurement of the isomeric 7 super(-) state (E super(*)=2219 keV, T sub(1/2)=5.9(8) mu s) in the neutron-rich super(126)Sn nucleus. The nucleus was produced by the fission of a relativistic super(238)U beam and reaction products were selected by the FRS fragment separator at GSI. For the first time, spin-alignment was observed after relativistic fission. It was used to deduce the g factor of the 7 super(-) isomeric state, g(7 super(-))=-0.098(9), from the measured perturbed angular distribution of its gamma decay using the RISING Cluster detectors. The observed value confirms the suggested [MathML equation] dominant configuration, which has been proposed for the 7 super(-) isomers in neutron-rich Sn isotopes. The failure of the g factor additivity rule and the importance of core polarization evolution with increasing distance from the doubly-magic super(132)Sn is discussed. The first observation of 18(8)% of spin-alignment produced by the relativistic fission of a super(238)U beam paves the way to study moments of neutron-rich (sub-)microsecond isomers, which are difficult to align by other means.