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

Ilie, G; Neyens, Gerda; Simpson, GS; Jolie, J; Blazhev, A; Grawe, H; Lozeva, RL; Vermeulen, Nele; Atanasova, L; Balabanski, DL; Becker, F; Bednarczyk, P; Brandau, C; Caceres, L; Chamoli, SK; Daugas, JM; Doornenbal, P; Gerl, J; Gorska, M; Grebosz, J; Hass, M; Ionescu-Bujor, M; Jungclaus, A; Kmiecik, M; Kojouharov, I; Kurz, N; Maj, A; Mallion, Stephen; Perru, O; Pfuetzner, M; Podolyak, Zs; Prokopowicz, W; De Rydt, Marieke; Saito, TR; Schaffner, H; Turzo, K; Walker, J; Werner-Malento, E; Wollersheim, HJ

doi:10.1016/j.physletb.2010.03.033

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

Author:

Ilie, G

Neyens, Gerda ; Simpson, GS ; Jolie, J ; Blazhev, A ; Grawe, H ; Lozeva, RL ; Vermeulen, Nele ; Atanasova, L ; Balabanski, DL ; Becker, F ; Bednarczyk, P ; Brandau, C ; Caceres, L ; Chamoli, SK ; Daugas, JM ; Doornenbal, P ; Gerl, J ; Gorska, M ; Grebosz, J ; Hass, M ; Ionescu-Bujor, M ; Jungclaus, A ; Kmiecik, M ; Kojouharov, I ; Kurz, N ; Maj, A ; Mallion, Stephen ; Perru, O ; Pfuetzner, M ; Podolyak, Zs ; Prokopowicz, W ; De Rydt, Marieke ; Saito, TR ; Schaffner, H ; Turzo, K ; Walker, J ; Werner-Malento, E ; Wollersheim, HJ

Keywords:

gRISING, nuclear moments, lifetimes, 127mSn g factor, shell model calculations, projectile fission reactions, fragmentation reactions, quadrupole-moments, angular-momentum, states, nuclei, isotopes, beams, gsi, Science & Technology, Physical Sciences, Astronomy & Astrophysics, Physics, Nuclear, Physics, Particles & Fields, Physics, Nuclear moments, Lifetimes, Shell model calculations, Projectile fission reactions, ANGULAR-MOMENTUM, FRAGMENTATION, STATES, NUCLEI, BEAMS, 0105 Mathematical Physics, 0201 Astronomical and Space Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 49 Mathematical sciences, 51 Physical sciences

Abstract:

We report on the g factor measurement of the isomeric 7(-) state (E* = 2219 keV, T-1/2 = 5.9(8) mu s) in the neutron-rich Sn-126 nucleus. The nucleus was produced by the fission of a relativistic U-238 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 7(-) factor of the 7 isomeric state, g(7(-)) -0.098(9), from the measured perturbed angular distribution of its gamma decay using the RISING Cluster detectors. The observed value confirms the suggested nu(h(11/2)(-1)d(3/2)(-1))) dominant configuration, which has been proposed for the 7(-) 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 Sn-132 is discussed. The first observation of 18(8)% of spin-alignment produced by the relativistic fission of a U-238 beam paves the way to study moments of neutron-rich (sub-)microsecond isomers, which are difficult to align by other means. (C) 2010 Elsevier B.V. All rights reserved.