0000000000145880
AUTHOR
P Rahkila
Spectroscopy of Hf-161 from low to high spin
High-spin states of Th-218
First beta-decay spectroscopy of In-135 and new beta-decay branches of In-134
Spectroscopy of 70Kr and isospin symmetry in the T = 1 f pg shell nuclei
International audience; The recoil-β tagging technique has been used in conjunction with the 40 Ca(32 S ,2n) reaction at a beam energy of 88 MeV to identify transitions associated with the decay of the 2 + and, tentatively, 4 + states in the nucleus 70 Kr. These data are used, along with previously published data, to examine the triplet energy differences (TED) for the mass 70 isobars. The experimental TED values are compared with shell model calculations, performed with the JUN45 interaction in the fpg model space, that include a J = 0 isospin nonconserving (INC) interaction with an isotensor strength of 100 keV. The agreement is found to be very good up to spin 4 and supports the expectat…
Changes in Transcription Factors during Muscle Differentiation
Identification of the crossing point at N=21 between normal and intruder configurations
R. Lica et al. -- 6 pags., 3 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0
Fine structure in the a decay of Lu-156 and Ta-158
Evidence for octupole collectivity in $$^{172}{\mathrm {Pt}}$$172Pt
Multiple chiral bands in Nd-137
Combined in-beam electron and gamma-ray spectroscopy of 184,186Hg\u2028
By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and gamma rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei (184,186)Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of (40)Ar and (148,150)Sm. The measured K- and L-conversion electron ratios confirmed the stretched E2 nature of several transitions of the yrast bands in (184,186)Hg. Additional information on the E0 component of the 2(2)(+) -> 2(1)(+) transition in (186)Hg was obtained.
alpha-spectroscopy studies of the new nuclides Pt-165 and Hg-170
First identification of rotational band structures in Re-166(75)91
Excited states in the odd-odd, highly neutron-deficient nucleus 166Re have been investigated via the 92Mo(78Kr, 3p1n) 166Re reaction. Prompt γ rays were detected by the JUROGAM II γ -ray spectrometer, and the recoiling fusion-evaporation products were separated by the recoil ion transport unit (RITU) gas-filled recoil separator and implanted into the Gamma Recoil Electron Alpha Tagging spectrometer located at the RITU focal plane. The tagging and coincidence techniques were applied to identify the γ -ray transitions in 166Re, revealing two collective, strongly coupled rotational structures, for the first time. The more strongly populated band structure is assigned to the πh11/2[514]9/2− ⊗ ν…
In-beam study of No-253 using the SAGE spectrometer
Excited states in Ra-217 populated in the alpha decay of Th-221
Evolving collective structures in the transitional nuclei 162W and 164W
Excited states in the neutron-deficient nuclides 162 74 W88 and 164 74 W90 were investigated by using the γ -ray spectrometer Jurogam. A change in structure is apparent from the first rotational alignments in 162W and 164W, whose rotationally aligned bands are interpreted as ν(h9/2) 2 and ν(i13/2) 2 configurations, respectively. The level schemes have been extended using recoil (-decay) correlations with the observation of excited collective structures. Configuration assignments have been made on the basis of comparisons of the deduced aligned angular momentum, as a function of rotational frequency, with the predictions of the cranked shell model. peerReviewed
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
Octupole states in 207Tl studied through β decay
The β decay of 207Hg into the single-proton-hole nucleus 207Tl has been studied through γ-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the πs−11/2, πd−13/2, and πh−111/2 shell model orbitals to the collective octupole vibration. Twenty-two states were observed lying between 2.6 and 4.0 MeV, eleven of which were observed for the first time, and 78 new transitions were placed. Two octupole states (s1/2-coupled) are identified and three more states (d3/2-coupled) are tentatively assigned using spin-parity inferences, while further h11/2-coupled states may also have been observed for the first time. Comparisons are made with st…
Normal and intruder configurations in $^{34}$Si populated in the $β^-$ decay of $^{34}$Mg and $^{34}$Al
The structure of $^{34}$Si was studied through $\gamma$ spectroscopy separately in the $\beta^-$ decays of $^{34}$Mg and $^{34}$Al at the ISOLDE facility of CERN. Different configurations in $^{34}$Si were populated independently from the two recently identified $\beta$-decaying states in $^{34}$Al having spin-parity assignments $J^\pi = 4^-$ dominated by the normal configuration $\pi (d_{5/2})^{-1} \otimes \nu (f_{7/2})$ and $J^\pi = 1^+$ by the intruder configuration $\pi (d_{5/2})^{-1} \otimes \nu (d_{3/2})^{-1}(f_{7/2})^{2}$. The paper reports on spectroscopic properties of $^{34}$Si such as an extended level scheme, spin and parity assignments based on log($ft$) values and $\gamma$-ray…
Fine structure in the alpha decay of high-spin isomers in Lu-155 and Hf-156
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-…
Beta-delayed proton emission from Mg-20
Reinvestigation of the excited states in the proton emitter Lu-151: Particle-hole excitations across the N = Z=64 subshell
In-beam gamma-ray and electron spectroscopy of Md-249,Md-251
New beta-decaying state in Bi-214
13 pags., 7 figs., 3 tabs.
Production cross section and decay study of Es-243 and Md-249
In the study of the odd-Z, even-N nuclei Es-243 and Md-249, performed at the University of Jyvaskyla, the fusion-evaporation reactions Au-197(Ca-48, 2n)Es-243 and Tl-203(Ca-48, 2n) Md-249 have been used for the first time. Fusion-evaporation residues were selected and detected using a gas-filled separator coupled with its focal-plane spectrometer. For Es-243, the recoil decay correlation analysis yielded a half-life of 24 +/- 3 s and a maximum production cross section of 37 +/- 10 nb. In the same way, a half-life of 26 +/- 1 s, an alpha-branching ratio of 75 +/- 5%, and a maximum production cross section of 300 +/- 80 nb were determined for Md-249. The decay properties of Es-245, the daught…
Study of shape coexistence in the very neutron deficient nucleus Hg-176
In-beam γ-ray and γ–γ coincidence measurements have been made for the very neutron deficient nucleus 176Hg using the recoil-decay tagging (RDT) technique. The irregular yrast sequence observed to I=10ℏ indicates that the prolate intruder band, seen in heavier Hg isotopes near the neutron midshell, is crossing the nearly spherical ground-state band of 176Hg above I=6ℏ. peerReviewed
(208)po populated through EC/beta(+) decay
The structure of 208Po resulting from the EC/β + decay of 208At was studied at CERN’s ISOLDE Decay Station (IDS). The high statistics afforded by the high yield of 208At and the high efficiency HPGe clusters at the IDS allowed for greater insight into lower intensity transitions and thus significant expansion of the 208Po level scheme. Furthermore, investigation into the isomeric state yielded a new half life 377(9) ns in addition to uncovering new transitions populating the state.