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Physica Scripta

Publication date: 2006-07-01
Volume: T125 Pages: 190 - 191
Publisher: Royal swedish acad sciences

Author:

Ekstrom, A
Cederkall, J ; Hurst, A ; Fahlander, C ; Banu, A ; Butler, P ; Eberth, J ; Gorska, M ; Habs, D ; Huyse, Marc ; Kester, O ; Niedermayer, O ; Nilsson, T ; Pantea, M ; Scheit, H ; Schwalm, D ; Sletten, G ; Ushasi, DP ; Van Duppen, Piet ; Warr, N ; Weisshaar, D

Keywords:

Science & Technology, Physical Sciences, Physics, Multidisciplinary, Physics, 01 Mathematical Sciences, 02 Physical Sciences, General Physics, 49 Mathematical sciences, 51 Physical sciences

Abstract:

In this paper, we report the preliminary result from the first Coulomb excitation experiment at REX-ISOLDE (Habs et al 1998 Nucl. Instrum. Methods B 139 128) using neutron-deficient Sn-beams. The motivation of the experiment is to deduce the reduced transition probability, B(E2; 2(+) -> 0(+)), for the sequence of neutron deficient, unstable, even-even Sn- isotopes from Sn-110 to ultimately Sn-110. Safe Coulomb excitation using a radioactive beam opens up a new path to study the lifetime of the first excited 2(+) state in these isotopes. The de-excitation path following fusion-evaporation reactions will for the even-even Sn isotopes pass via an isomeric 6(+) state, located at higher energy, which thus hampers measurements of the lifetime of the first excited state using, e. g., recoil-distance methods. For this reason the reduced transition probability of the first excited 2(+) state has remained unknown in this chain of isotopes although the B(E2) value of the stable isotope Sn-112 was measured approximately 30 years ago (see, e. g., Stelson et al 1970 Phys. Rev. C 2 2015). Our experiment is thus the first to accomplish a measurement of this quantity in Sn-110. It is believed that the determination of the B(E2) value in Sn-110 will indicate the turnover point from a trend of increasing B(E2) values for the heavier isotopes to a trend characterized by less collectivity. Our first preliminary result indicates that this assumption may well be correct.