Coulomb excitation of Rn222

Studies of reflection asymmetry in heavy nuclei

“…Gamma rays and scattered ions emitted following the excitation of the target and projectile nuclei were detected as before. Also, 222 Rn (Z = 86, N = 136) ions were produced in the same manner as for 224,226 Rn and accelerated in HIE-ISOLDE to 4.23 MeV/u [11]. The accelerated ions then bombarded, with an intensity of 6 × 10 5 ions/s, the 60 Ni and 120 Sn targets as before.…”

“…Their placement in the level scheme was determined through analysis of a γ − γ coincidence matrix collected with data from both targets. The feeding from the so-called β-band to the negative-parity states is appreciable (see figure 8 in [11]) and has to be taken into account in the determination of E3 matrix elements (section 2.3). Low-lying collective bands are also observed in the Coulomb excitation of 220 Rn [3], 224 Ra [3] and 228 Ra [10] but are populated very weakly in the case of 222 Ra, see figure 1.…”

“…Values of E1, E2 and E3 matrix elements in 222 Rn [11], 222 Ra [10] and 228 Ra [10] were obtained by using the Coulomb-excitation least-squares fitting code GOSIA [25]. GOSIA was employed to calculate excitation probabilities and subsequent γ-ray decay intensities of excited states for a given set of electromagnetic matrix elements.…”

Evolution of quadrupole-octupole collectivity in the even–even 54 ≤ Z ≤ 58 nuclei

“…Although the subject of octupole (reflection-asymmetric) deformations in atomic nuclei dates from the early fifties [1][2][3][4][5] nowadays it gains actuality due to the massive appearance of new data on octupole collectivity [6][7][8][9][10][11][12][13][14][15] and, especially, proofs for the presence of axial octupole (pear) shapes in the ground states of light actinide nuclei (such as 222,224 Ra [16][17][18]) and nuclei in the region of Ba and Ce ( 144,146 Ba [19]) isotopes (see recent reviews [17,20]). A number of theoretical models aiming to describe different aspects of collective and microscopic dynamics in nuclei with reflection-asymmetric degrees of freedom [21] have been gradually developing over the years .…”