Multiple Coulomb excitation of198Hg and200Hg

Abstract

Multiple Coulomb excitation measurements on 198"2~176 have been performed with 5 MeV/amu 2~ projectiles and B(E2)-values are determined for transitions between states up to spin 8 +. In t98Hg a reduction of the B(E2)-value for the yrast transition 8+--* 6 + by a factor of 3 as compared to the rigid rotor prediction is observed, which supports the earlier proposed idea that the ground state band is crossed between the 6 + and 8 + state by a weakly interacting viii, 2 rotation aligned band. In each of the two nuclei, 198Hg and 2~176 a state with a possible U=8 + assignment is observed, which is tentatively interpreted as the 8--member of the ground state band.

Rotation aligned bands and configuration dependent interaction in189Hg

“…6 the crossing frequencies co~ deduced from high spin band structures in ass-198Hg [1,2,[6][7][8][9][10] are plotted as a function of neutron number N. The figure includes data on the AB and B C pair breaking with spectators built of the vacuum, A, E, F, AE and AF configurations. 6 the crossing frequencies co~ deduced from high spin band structures in ass-198Hg [1,2,[6][7][8][9][10] are plotted as a function of neutron number N. The figure includes data on the AB and B C pair breaking with spectators built of the vacuum, A, E, F, AE and AF configurations.…”

“…The Hg isotopes have been extensively investigated, both experimentally [1][2][3][4][5][6][7][8][9][10] and theoretically [11][12][13]. Of particular interest is the description of their high spin structure in terms of rotation aligned quasiparticle states and bands built on these states.…”

Coupling of one and two quasiparticles to a Bohr-Mottelson core in195,196,197,198Hg

“…The final conclusions are drawn in Sect. 6. There we also compare the results of the present work to those obtained in the framework of other models.…”

Multiple coulomb excitation of202Hg and204Hg

“…This allows for a Doppler shift correction of the measured y-ray spectra on an event-by-event basis and simultaneously provides y-intensities as a function of the scattering angle over a wide range of impact parameters, which is essential for the determination of B(E2) values [- [6][7][8]. The measurements were carried out under almost identical conditions as our earlier experiment for 198'2~176 [5], were also the target preparation is described. Examples of the measured y-ray spectra are shown in Fig.…”

“…2. The double-hump structure of the spectra is due to the fact that the scattered projectile and target nuclei cannot be distinguished, as outlined in detail in [5], because of their almost identical masses. We observe, apart from the known 2 + +0 + and 4 + --*2 + transitions, in both nuclei one strong y-line, which we assign as 6 + -+4 + transition on the basis of the impact parameter dependence of the y-yield (see Fig.…”