0000000000984078
AUTHOR
Lp Gaffney
Laser-assisted nuclear decay spectroscopy of Au-176,Au-177,Au-179
ispartof: PHYSICAL REVIEW C vol:104 issue:2 status: published
Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive $^{222}$Ra and $^{228}$Ra Beams
There is sparse direct experimental evidence that atomic nuclei can exhibit stable pear shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity in radium isotopes, electric octupole ($E3$) matrix elements have been determined for transitions in $^{222,228}$Ra nuclei using the method of sub-barrier, multi-step Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of $E$3 matrix elements for different nuclear transitions is explained by describing $^{222}$Ra as pear-shaped with stable octupole deformation, while $^{228}$Ra behaves like an octupole vibrator.
Fine structure in the α decay of 218At
An α-decay study of 218At was performed at the CERN-ISOLDE facility. Laser-ionized beams of 218At were mass separated and implanted into an α−γ detection setup. Coincidence α−γ data were collected for the first time and a more precise half-life value of T1/2=1.27(6) s was measured. A new α-decay scheme was deduced based on the extracted reduced α-decay widths for fine-structure decays. The results from this work lead to a preferred spin and parity assignment of Jπ=(3−); however, Jπ=(2)− cannot be fully excluded.
The observation of vibrating pear-shapes in radon nuclei (vol 10, 2473, 2019)
Low-energy Coulomb excitation of Fe-62 and Mn-62 following in-beam decay of Mn-62
Collective 2(1)(+) excitations in Po-206 and Rn-208,Rn-210
In the present study, values have been measured in the 208,210Rn and 206Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N=126 closed shell. Such an effect is confirmed by the observed increased collectivity of the transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRPA framework. ispartof: European Physical Journal A, Hadrons and Nuclei vo…
α -decay spectroscopy of the N=130 isotones Ra 218 and Th 220: Mitigation of α -particle energy summing with implanted nuclei
An analysis technique has been developed in order to mitigate energy summing due to sequential short-lived α decays from nuclei implanted into a silicon detector. Using this technique, α-decay spectroscopy of the N=130 isotones Ra218 (Z=88) and Th220 (Z=90) has been performed. The energies of the α particles emitted in the Ra218→Rn214 and Th220→Ra216 ground-state-to-ground-state decays have been measured to be 8381(4) keV and 8818(13) keV, respectively. The half-lives of the ground states of Ra218 and Th220 have been measured to be 25.99(10) μs and 10.4(4) μs, respectively. The half-lives of the ground states of the α-decay daughters, Rn214 and Ra216, have been measured to be 259(3) ns and …
alpha-decay spectroscopy of the N=130 isotones Ra-218 and Th-220: Mitigation of alpha-particle energy summing with implanted nuclei
Fast-timing study of the l -forbidden 12+→32+ M1 transition in Sn 129 FAST-TIMING STUDY of the l -FORBIDDEN ⋯ R. LICǎ et al.
© 2016 authors. Published by the American Physical Society.The levels in Sn129 populated from the β- decay of In129 isomers were investigated at the ISOLDE facility of CERN using the newly commissioned ISOLDE Decay Station (IDS). The lowest 12+ state and the 32+ ground state in Sn129 are expected to have configurations dominated by the neutron s12 (l=0) and d32 (l=2) single-particle states, respectively. Consequently, these states should be connected by a somewhat slow l-forbidden M1 transition. Using fast-timing spectroscopy we have measured the half-life of the 12+ 315.3-keV state, T12= 19(10) ps, which corresponds to a moderately fast M1 transition. Shell-model calculations using the CD-…