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1. Direct observation of E0 transitions in 188Pb through in-beam spectroscopy

Author: P. Papadakis, J. Pakarinen, A.D. Briscoe, D.M. Cox, R. Julin, K. Auranen, T. Grahn, P.T. Greenlees, K. Hadyńska-Klek, A. Herzáň, R.-D. Herzberg, U. Jakobsson, S. Juutinen, J. Konki, M. Leino, A. Mistry, D. O'Donnell, P. Peura, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, S. Stoltze, J. Sorri, J. Uusitalo, and K. Wrzosek-Lipska
Subjects: In-beam spectroscopy, Shape coexistence, Internal conversion electrons, Physics, QC1-999
Abstract: Competing configurations, assigned with three different shapes, are mixed at low angular momentum in the neutron-deficient 188Pb nucleus. Here, we present a simultaneous conversion electron and γ-ray in-beam spectroscopic precision measurement employing the sage spectrometer. The level energy of the first excited state, 02+, has been determined at 591(1)keV through direct measurement of conversion electrons. By using the intensity of the observed 02+→01+ transition to the ground state, the feeding of the 02+ state has been determined for the first time, which suggests the 02+ state is the head of the predominantly prolate band. The compositions of the 42+→41+ and 22+→21+ inter-band transitions have been determined, indicating configuration mixing between the bands.
Published: 2024
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2. First observation of excited states in 120La and its impact on the shape evolution in the A ≈ 120 mass region

Author: P.M. Jodidar, C.M. Petrache, B.F. Lv, E.A. Lawrie, A. Astier, S. Guo, K.K. Zheng, K. Auranen, A.D. Briscoe, T. Grahn, P.T. Greenlees, A. Illana, H. Joukainen, R. Julin, J. Louko, M. Luoma, H. Jutila, J. Ojala, J. Pakarinen, A.M. Plaza, P. Rahkila, P. Ruotsalainen, J. Sarén, A. Tolosa-Delgado, J. Uusitalo, G. Zimba, I. Kuti, A. Krakó, C. Andreoiu, D.T. Joss, R.D. Page, E.A. Cederlöf, and A. Ertoprak
Subjects: Nuclear reaction: 58Ni(64Zn,pn)120La, E= 255 MeV, Measured γγγ-coincidences, Eγ, Iγ, Angular correlations, Physics, QC1-999
Abstract: Excited states have been observed for the first time in the very neutron-deficient odd-odd nucleus 57120La63. The observed γ rays have been assigned based on coincidences with lanthanum X rays measured with the JUROGAM 3 array and with A=120 fusion-evaporation residues measured with the MARA separator. The observed γ rays form a rotational band which decays to the ground state via a cascade of four low-energy transitions. Based on the systematic comparisons with the heavier odd-odd La isotopes we assign spin-parity 4+ to the ground state and a πh11/2⊗νh11/2 configuration to the rotational band. The nuclear shape has been investigated by the cranked Nilsson-Strutinsky model. Two quasiparticle plus triaxial rotor model calculations including the np interaction nicely reproduce the spin of the inversion between the even- and odd-spin cascades of E2 transitions, giving credit to the np interaction as an important parameter responsible for the mechanism inducing the inversion. The position of the Fermi levels, in particular for neutrons, also has a strong impact on the observed inversion in the chain of lanthanum nuclei.
Published: 2024
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3. Octupole correlations in the N = Z + 2 = 56 110Xe nucleus

Author: A. Illana, R.M. Pérez-Vidal, D. Stramaccioni, J.J. Valiente-Dobón, T.R. Rodriguez, L.M. Robledo, A. Poves, K. Auranen, O. Beliuskina, C. Delafosse, T. Eronen, Z. Ge, S. Geldhof, W. Gins, T. Grahn, P.T. Greenlees, H. Joukainen, R. Julin, H. Jutila, A. Kankainen, M. Leino, J. Louko, M. Luoma, D. Nesterenko, J. Ojala, J. Pakarinen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, J. Uusitalo, and G.L. Zimba
Subjects: Octupole deformations, 110Xe, N=Z=56 region, Fusion evaporation reactions, Physics, QC1-999
Abstract: This letter reports on the first observation of an octupole band in the neutron-deficient (N=Z+2) nucleus 110Xe. The 110Xe nuclei were produced via the 54Fe(58Ni,2n) fusion-evaporation reaction. The emitted γ rays were detected using the jurogam 3 γ-ray spectrometer, while the fusion-evaporation residues were separated with the MARA separator at the Accelerator Laboratory of the University of Jyväskylä, Finland. The experimental observation of the low-lying 3− and 5− states and inter-band E1 transitions between the ground-state band and the octupole band proves the importance of octupole correlations in this region. These new experimental data combined with theoretical calculations using the symmetry-conserving configuration-mixing method, based on a Gogny energy density functional, have been interpreted as an evidence of enhanced octupole correlations in neutron-deficient xenon isotopes.
Published: 2024
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4. Isospin symmetry in the T = 1,A = 62 triplet

Author: K. Wimmer, P. Ruotsalainen, S.M. Lenzi, A. Poves, T. Hüyük, F. Browne, P. Doornenbal, T. Koiwai, T. Arici, K. Auranen, M.A. Bentley, M.L. Cortés, C. Delafosse, T. Eronen, Z. Ge, T. Grahn, P.T. Greenlees, A. Illana, N. Imai, H. Joukainen, R. Julin, A. Jungclaus, H. Jutila, A. Kankainen, N. Kitamura, B. Longfellow, J. Louko, R. Lozeva, M. Luoma, B. Mauss, D.R. Napoli, M. Niikura, J. Ojala, J. Pakarinen, X. Pereira-Lopez, P. Rahkila, F. Recchia, M. Sandzelius, J. Sarén, R. Taniuchi, H. Tann, S. Uthayakumaar, J. Uusitalo, V. Vaquero, R. Wadsworth, G. Zimba, and R. Yajzey
Subjects: Physics, QC1-999
Abstract: Excited states in the Tz=0,−1 nuclei 62Ga and 62Ge were populated in direct reactions of relativistic radioactive ion beams at the RIBF. Coincident γ rays were measured with the DALI2+ array and uniquely assigned to the A=62 isobars. In addition, 62Ge was also studied independently at JYFL-ACCLAB using the 24Mg(40Ca,2n)62Ge fusion-evaporation reaction. The first excited T=1,Jπ=2+ states in 62Ga and 62Ge were identified at 979(1) and 965(1) keV, respectively, resolving discrepant interpretations in the literature. States beyond the first 2+ state in 62Ge were also identified for the first time in the present work. The results are compared with shell-model calculations in the fp model space. Mirror and triplet energy differences are analyzed in terms of individual charge-symmetry and charge-independence breaking contributions. The MED results confirm the shrinkage of the p-orbits' radii when they are occupied by at least one nucleon on average.
Published: 2023
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5. Decay spectroscopy at the two-proton drip line: Radioactivity of the new nuclides 160Os and 156W

Author: A.D. Briscoe, R.D. Page, J. Uusitalo, D.T. Joss, M.A.M. AlAqeel, B. Alayed, B. Andel, S. Antalic, K. Auranen, H. Ayatollahzadeh, H. Badran, L. Barber, G. Beeton, M. Birova, V. Bogdanoff, R.M. Clark, J.G. Cubiss, D.M. Cullen, J. Deary, U. Forsberg, T. Grahn, P.T. Greenlees, J.B. Hilton, A. Illana, H. Joukainen, D.S. Judson, R. Julin, H. Jutila, J.M. Keatings, M. Labiche, M. Leino, M.C. Lewis, J. Louko, M. Luoma, I. Martel, A. McCarter, P.P. McKee, P. Mosat, S.N. Nathaniel, O. Neuvonen, D. O'Donnell, J. Ojala, C.A.A. Page, A.M. Plaza, J. Pakarinen, P. Papadakis, E. Parr, J. Partanen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, B. Saygi, J. Smallcombe, J.F. Smith, J. Sorri, C.M. Sullivan, S. Szwec, H. Tann, A. Tolosa-Delgado, E. Uusikylä, M. Venhart, L.J. Waring, and G. Zimba
Subjects: Physics, QC1-999
Abstract: The radioactivity of 76160Os84 and 74156W82 that lie at the two-proton drip line has been measured in an experiment performed at the Accelerator Laboratory of the University of Jyväskylä. The 160Os nuclei were produced using fusion-evaporation reactions induced by a beam of 310 MeV 58Ni ions bombarding a 106Cd target. The 160Os ions were separated in flight using the recoil separator MARA and implanted into a double-sided silicon strip detector, which was used to measure their decays. The α decays of the ground state of 160Os (Eα = 7092(15) keV, t1/2 = 97−32+97 μs) and its isomeric state (Eα = 8890(10) keV, t1/2 = 41−9+15 μs) were measured, allowing the excitation energy of the isomer to be determined as 1844(18) keV. These α-decay properties and the excitation energy of the isomer are compared with systematics. The α decays were correlated with subsequent decays to investigate the β decays of the ground state of 156W, revealing that unlike its isotones, both low-lying isomers were populated in its daughter nuclide, 156Ta. An improved value for the half-life of the proton-decaying high-spin isomeric state in 73156Ta83 of 333−22+25 ms was obtained in a separate experiment using the same experimental systems with a 102Pd target. This result was employed to improve the precision of the half-life determined for 156W, which was measured as 157−34+57 ms.
Published: 2023
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6. The spectroscopic quadrupole moment of the 21+ state of 12C: A benchmark of theoretical models

Author: J. Saiz-Lomas, M. Petri, I.Y. Lee, I. Syndikus, S. Heil, J.M. Allmond, L.P. Gaffney, J. Pakarinen, H. Badran, T. Calverley, D.M. Cox, U. Forsberg, T. Grahn, P. Greenlees, K. Hadyńska-Klȩk, J. Hilton, M. Jenkinson, R. Julin, J. Konki, A.O. Macchiavelli, M. Mathy, J. Ojala, P. Papadakis, J. Partanen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, S. Stolze, J. Uusitalo, and R. Wadsworth
Subjects: Physics, QC1-999
Abstract: The spectroscopic quadrupole moment of the first 2+ state of 12C has been measured employing the Coulomb-excitation re-orientation technique. Our result of Qs(21+)=+9.3−3.8+3.5efm2 suggests a larger oblate deformation than previously reported. Combining this with the consistently re-analyzed adopted value, we present the most precise value to date of Qs(21+)=+9.5(18)efm2, which is consistent with a geometrical rotor description. This simple outcome is compared to state-of-the-art shell-model, mean-field, ab initio calculations, cluster-based and geometrical-like theories, which show varying degrees of emergent quadrupole collectivity.
Published: 2023
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7. Experimental observation of the M1 scissors mode in 254No

Author: F.L. Bello Garrote, A. Lopez-Martens, A.C. Larsen, I. Deloncle, S. Péru, F. Zeiser, P.T. Greenlees, B.V. Kheswa, K. Auranen, D.L. Bleuel, D.M. Cox, L. Crespo Campo, F. Giacoppo, A. Görgen, T. Grahn, M. Guttormsen, T.W. Hagen, L. Harkness-Brennan, K. Hauschild, G. Henning, R.-D. Herzberg, R. Julin, S. Juutinen, T.A. Laplace, M. Leino, J.E. Midtbø, V. Modamio, J. Pakarinen, P. Papadakis, J. Partanen, T. Renstrøm, K. Rezynkina, M. Sandzelius, J. Sarén, C. Scholey, S. Siem, J. Sorri, S. Stolze, and J. Uusitalo
Subjects: Scissors mode, γ-strength function, Transfermium nuclides, Physics, QC1-999
Abstract: We present the first experimental evidence of the scissors mode in the superheavy nucleus 254No produced in the 208Pb(48Ca, 2nγ))254No reaction. The spectrum of γ rays emitted by the excited 254No nuclei shows an enhanced γ-ray yield for transition energies of ≈2.5 MeV. By measuring the linear polarization properties of the emitted γ rays, we confirm that the transitions in the enhancement region are predominantly of magnetic-dipole character, characteristic for the scissors mode. To further characterize the enhanced γ-ray yield, simulations of the electromagnetic decay of 254No were performed. The observed enhancement is reproduced by including an M1 component in the γ strength function with total strength B(M1↑)=11.8(19)μN2. This is in good agreement with the integrated M1 strength from sum-rule estimates and new calculations within the quasi-particle random-phase approximation presented here. Our results provide a stringent test of phenomenological formulae for the scissors mode currently used in stellar nucleosynthesis calculations. We find that those formulae are not satisfactory, and we recommend using sum-rule estimates assuming a rigid-body moment of inertia instead for describing the scissors mode in superheavy nuclei.
Published: 2022
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8. Evidence against the wobbling nature of low-spin bands in 135Pr

Author: B.F. Lv, C.M. Petrache, E.A. Lawrie, S. Guo, A. Astier, K.K. Zheng, H.J. Ong, J.G. Wang, X.H. Zhou, Z.Y. Sun, P.T. Greenlees, H. Badran, T. Calverley, D.M. Cox, T. Grahn, J. Hilton, R. Julin, S. Juutinen, J. Konki, J. Pakarinen, P. Papadakis, J. Partanen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, S. Stolze, J. Uusitalo, B. Cederwall, A. Ertoprak, H. Liu, I. Kuti, J. Timár, A. Tucholski, J. Srebrny, and C. Andreoiu
Subjects: γγγ-coincidences, Angular correlations, Particle rotor model, Wobbling bands, Physics, QC1-999
Abstract: The electromagnetic character of the ΔI=1 transitions connecting the 1- to 0-phonon and the 2- to 1-phonon wobbling bands should be dominated by an E2 component, due to the collective motion of the entire nuclear charge. In the present work it is shown, based on combined angular correlation and linear polarization measurements, that the mixing ratios of all analyzed connecting transitions between low-lying bands in 135Pr interpreted as 0-, 1-, and 2-phonon wobbling bands, have absolute values smaller than one. This indicates predominant M1 magnetic character, which is incompatible with the proposed wobbling nature. All experimental observables are instead in good agreement with quasiparticle-plus-triaxial-rotor model calculations, which describe the bands as resulting from a rapid re-alignment of the total angular momentum from the short to the intermediate nuclear axis.
Published: 2022
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9. Evidence of oblate-prolate shape coexistence in the strongly-deformed nucleus 119Cs

Author: K.K. Zheng, C.M. Petrache, Z.H. Zhang, P.W. Zhao, Y.K. Wang, A. Astier, B.F. Lv, P.T. Greenlees, T. Grahn, R. Julin, S. Juutinen, M. Luoma, J. Ojala, J. Pakarinen, J. Partanen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, H. Tann, J. Uusitalo, G. Zimba, B. Cederwall, Ö. Aktas, A. Ertoprak, W. Zhang, S. Guo, M.L. Liu, I. Kuti, B.M. Nyakó, D. Sohler, J. Timár, C. Andreoiu, M. Doncel, D.T. Joss, and R.D. Page
Subjects: Nuclear reaction:58Ni(64Zn,3p)119Cs, Measured γγγ-coincidences, Angular correlations, Linear polarization, Model calculation, Oblate-prolate coexistence, Physics, QC1-999
Abstract: Prolate-oblate shape coexistence close to the ground state in the strongly-deformed proton-rich A≈120 nuclei is reported for the first time. One of the four reported bands in 119Cs, built on a 11/2− state at 670 keV, consists of nearly degenerate signature partners, and has properties which unequivocally indicate the strongly-coupled πh11/2[505]11/2− configuration associated with oblate shape. Together with the decoupled πh11/2[541]3/2− band built on the 11/2− prolate state at 110 keV, for which a half-life of T1/2=55(5)μs has been measured, the new bands bring evidence of shape coexistence at low spin in the proton-rich strongly deformed A≈120 nuclei, a phenomenon predicted since long time, but not yet observed. Calculations using the particle-number conserving cranked shell model and two dimensional tilted axis cranking covariant density functional theory support and well reproduce the observed oblate and prolate coexisting low-energy states in 119Cs.
Published: 2021
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10. Lifetime measurements of excited states in 169,171,173Os: Persistence of anomalous B(E2) ratios in transitional rare earth nuclei in the presence of a decoupled i13/2 valence neutron

Author: W. Zhang, B. Cederwall, M. Doncel, Ö. Aktas, A. Ertoprak, R. Liotta, C. Qi, T. Grahn, B.S. Nara Singh, D.M. Cullen, D. Hodge, M. Giles, S. Stolze, H. Badran, T. Braunroth, T. Calverley, D.M. Cox, Y.D. Fang, P.T. Greenlees, J. Hilton, E. Ideguchi, R. Julin, S. Juutinen, M. Kumar Raju, H. Li, H. Liu, S. Matta, P. Subramaniam, V. Modamio, J. Pakarinen, P. Papadakis, J. Partanen, C.M. Petrache, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, M.J. Taylor, J. Uusitalo, and J.J. Valiente-Dobón
Subjects: Physics, QC1-999
Abstract: Lifetimes of low-lying excited states in the νi13/2+ bands of the neutron-deficient osmium isotopes 169,171,173Os have been measured for the first time using the recoil-distance Doppler shift and recoil-isomer tagging techniques. An unusually low value is observed for the ratio B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) in 169Os, similar to the “anomalously” low values of the ratio B(E2;41+→21+)/B(E2;21+→0gs+) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighbouring 168,170Os. Furthermore, the evolution of B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) with increasing neutron number in the odd-mass isotopic chain 169,171,173Os is observed to follow the same trend as observed previously in the even-even Os isotopes. These findings indicate that the possible quantum phase transition from a seniority conserving structure to a collective regime as a function of neutron number suggested for the even-even systems is maintained in these odd-mass osmium nuclei, with the odd valence neutron merely acting as a “spectator”. As for the even-even nuclei, the phenomenon is highly unexpected for nuclei that are not situated near closed shells.
Published: 2021
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11. Population of a low-spin positive-parity band from high-spin intruder states in 177Au: The two-state mixing effect

Author: M. Venhart, M. Balogh, A. Herzáň, J.L. Wood, F.A. Ali, D.T. Joss, A.N. Andreyev, K. Auranen, R.J. Carroll, M.C. Drummond, J.L. Easton, P.T. Greenlees, T. Grahn, A. Gredley, J. Henderson, U. Jakobsson, R. Julin, S. Juutinen, J. Konki, E.A. Lawrie, M. Leino, V. Matoušek, C.G. McPeake, D. O'Donnell, R.D. Page, J. Pakarinen, P. Papadakis, J. Partanen, P. Peura, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, B. Saygı, M. Sedlák, C. Scholey, J. Sorri, S. Stolze, A. Thornthwaite, R. Urban, J. Uusitalo, M. Veselský, and F.P. Wearing
Subjects: In-beam spectroscopy, γ rays, 177Au, 179Au, Two-state mixing, Physics, QC1-999
Abstract: The extremely neutron-deficient isotopes 177,179Au were studied by means of in-beam γ-ray spectroscopy. Specific tagging techniques, α-decay tagging in 177Au and isomer tagging in 179Au, were used for these studies. Feeding of positive-parity, nearly spherical states, which are associated with 2d3/2 and 3s1/2 proton-hole configurations, from the 1i13/2 proton-intruder configuration was observed in 177Au. Such a decay path has no precedent in odd-Au isotopes and it is explained by the effect of mixing of wave functions of the initial state.
Published: 2020
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12. Spectroscopy at the two-proton drip line: Excited states in 158W

Author: D.T. Joss, R.D. Page, A. Herzán, L. Donosa, J. Uusitalo, R.J. Carroll, I.G. Darby, K. Andgren, B. Cederwall, S. Eeckhaudt, T. Grahn, P.T. Greenlees, B. Hadinia, U. Jakobsson, P.M. Jones, R. Julin, S. Juutinen, M. Leino, A.-P. Leppanen, M. Nyman, D. O'Donnell, J. Pakarinen, P. Rahkila, M. Sandzelius, J. Sarén, C. Scholey, D. Seweryniak, J. Simpson, and J. Sorri
Subjects: Multiparticle excited states, Proton radioactivity, Physics, QC1-999
Abstract: Excited states have been identified in the heaviest known even-Z N=84 isotone 158W, which lies in a region of one-proton emitters and the two-proton drip line. The observation of γ-ray transitions feeding the ground state establishes the excitation energy of the yrast 6+ state confirming the spin-gap nature of the α-decaying 8+ isomer. The 8+ isomer is also expected to be unbound to two-proton emission but no evidence for this decay mode was observed. An upper limit for the two-proton decay branch has been deduced as b2p≤ 0.17% at the 90% confidence level. The possibility of observing two-proton emission from multiparticle isomers in nearby nuclides is considered.
Published: 2017
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13. Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk

Author: J. Konki, J. Khuyagbaatar, J. Uusitalo, P.T. Greenlees, K. Auranen, H. Badran, M. Block, R. Briselet, D.M. Cox, M. Dasgupta, A. Di Nitto, Ch.E. Düllmann, T. Grahn, K. Hauschild, A. Herzán, R.-D. Herzberg, F.P. Heßberger, D.J. Hinde, R. Julin, S. Juutinen, E. Jäger, B. Kindler, J. Krier, M. Leino, B. Lommel, A. Lopez-Martens, D.H. Luong, M. Mallaburn, K. Nishio, J. Pakarinen, P. Papadakis, J. Partanen, P. Peura, P. Rahkila, K. Rezynkina, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, S. Stolze, B. Sulignano, Ch. Theisen, A. Ward, A. Yakushev, and V. Yakusheva
Subjects: Isotopes with mass 236–240, 240Es, 236Bk, α decay, Electron-capture delayed fission, Fusion–evaporation reactions, Physics, QC1-999
Abstract: The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion–evaporation reaction 209Bi(34S,3n)240Es. Half-lives of 6(2)s and 22−6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies Eα=8.19(3)MeV and 8.09(3)MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16(6) and 0.04(2) were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.
Published: 2017
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14. Lifetime measurements of excited states in 163W and the implications for the anomalous B(E2) ratios in transitional nuclei

Author: M.C. Lewis, D.T. Joss, B. Sayğı, R.D. Page, D.M. Cullen, L. Barber, M.M. Giles, J. Simpson, M.A.M. Al-Aqeel, H. Badran, T. Braunroth, A.D. Briscoe, T. Calverley, A. Dewald, M. Doncel, T. Grahn, P.T. Greenlees, C. Henrich, A. Herzáň, R.-D. Herzberg, E. Higgins, J. Hilton, S. Ilieva, R. Julin, S. Juutinen, J. Keatings, T. Kröll, M. Labiche, K. Mashtakov, B.S. Nara Singh, E. Parr, J. Partanen, E.S. Paul, P. Rahkila, M. Sandzelius, J. Sarén, C. Scholey, M. Siciliano, P. Spagnoletti, S. Stolze, S.V. Szwec, M.J. Taylor, and J. Uusitalo
Subjects: Physics, QC1-999
Abstract: This letter reports lifetime measurements of excited states in the odd-N nucleus 163W using the recoil-distance Doppler shift method to probe the core polarising effect of the i13/2 neutron orbital on the underlying soft triaxial even-even core. The ratio B(E2:21/2+→17/2+)/B(E2:17/2+→13/2+) is consistent with the predictions of the collective rotational model. The deduced B(E2) values provide insights into the validity of collective model predictions for heavy transitional nuclei and a geometric origin for the anomalous B(E2) ratios observed in nearby even-even nuclei is proposed. Keywords: Mean lifetimes, B(E2) reduced transition probabilities, Recoil-distance Doppler-shift method, Nuclear deformation, Gamma-ray Spectroscopy
Published: 2019
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15. Offline commissioning of a new gas cell for the MARA Low-Energy Branch

Author: A. Zadvornaya, J. Romero, T. Eronen, W. Gins, A. Kankainen, I.D. Moore, P. Papadakis, I. Pohjalainen, M. Reponen, S. Rinta-Antila, J. Sarén, D. Simonovski, and J. Uusitalo
Subjects: 223Ra α-recoil source, Nuclear and High Energy Physics, tutkimuslaitteet, gas cell, in-gas laser ionization, ydinfysiikka, Instrumentation, MARA-LEB
Abstract: Results of offline commissioning tests for a new dedicated gas cell for the Mass Analysing Recoil Apparatus (MARA) Low-Energy Branch are reported. Evacuation time, ion survival and transport efficiency in helium buffer gas were characterized with a radioactive 223Ra 𝛼-recoil source. Suppression of the ion signal, originating from non-neutralized species in the gas cell, was explored with 219Rn ions, the daughter recoil of 223Ra, as a function of voltage applied to one of the ion-collector electrodes. Two-step laser resonance ionization of stable tin isotopes produced inside the gas cell from a heated bronze filament was demonstrated, and broadening of the atomic resonances in argon buffer gas was studied. These tests indicate the suitability of the new gas cell for future in-gas laser spectroscopy studies of exotic nuclei at the Accelerator Laboratory of the University of Jyväskylä. peerReviewed
Published: 2023

16. In-beam $$\gamma $$-ray spectroscopy of $$^{94}$$Ag

Author: X. Pereira-López, M. A. Bentley, R. Wadsworth, P. Ruotsalainen, S. M. Lenzi, U. Forsberg, K. Auranen, A. Blazhev, B. Cederwall, T. Grahn, P. Greenlees, A. Illana, D. G. Jenkins, R. Julin, H. Jutila, S. Juutinen, X. Liu, R. Llewelyn, M. Luoma, K. Moschner, C. Müller-Gatermann, B. S. Nara Singh, F. Nowacki, J. Ojala, J. Pakarinen, P. Papadakis, P. Rahkila, J. Romero, M. Sandzelius, J. Sarén, H. Tann, S. Uthayakumaar, J. Uusitalo, J. G. Vega-Romero, J. M. Vilhena, R. Yajzey, W. Zhang, and G. Zimba
Subjects: Nuclear and High Energy Physics
Abstract: A recoil-beta-tagging experiment has been performed to study the excited $$T=0$$ T = 0 and $$T=1$$ T = 1 states in the odd–odd $$N=Z$$ N = Z nucleus $$^{94}$$ 94 Ag, populated via the $$^{40}$$ 40 Ca($$^{58}$$ 58 Ni,1p3n)$$^{94}$$ 94 Ag reaction. The experiment was conducted using the MARA recoil separator and JUROGAM3 array at the Accelerator Laboratory of the University of Jyväskylä. Through correlating fast, high-energy beta decays at the MARA focal plane with prompt $$\gamma $$ γ rays emitted at the reaction target, a number of transitions between excited states in $$^{94}$$ 94 Ag have been identified. The timing characteristics of these transitions confirm that they fall within decay sequences that feed the short-lived $$T=1$$ T = 1 ground state of $$^{94}$$ 94 Ag. The transitions are proposed to proceed within and between the sets of states with $$T=0$$ T = 0 and $$T=1$$ T = 1 . Possible correspondence between some of these transitions from analog states in $$^{94}$$ 94 Pd has been discussed, and shell-model calculations including multipole and monopole electromagnetic effects have been presented, in order to enable predictions of the decay patterns between the $$T=0$$ T = 0 and $$T=1$$ T = 1 states and to allow a theoretical set of Coulomb energy differences to be calculated for the $$A = 94$$ A = 94 $$T=1$$ T = 1 analog states.
Published: 2023

17. Decay spectroscopy of Os171,172 and Ir171,172,174

Author: W. Zhang, B. Cederwall, M. Doncel, Ö. Aktas, A. Ertoprak, C. Qi, T. Grahn, B. S. Nara Singh, D. M. Cullen, D. Hodge, M. Giles, S. Stolze, K. Auranen, H. Badran, T. Braunroth, T. Calverley, D. M. Cox, Y. D. Fang, P. T. Greenlees, J. Hilton, E. Ideguchi, R. Julin, S. Juutinen, M. Kumar Raju, M. Leino, H. Li, H. Liu, S. Matta, P. Subramaniam, V. Modamio, J. Pakarinen, P. Papadakis, J. Partanen, C. M. Petrache, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, M. J. Taylor, J. Uusitalo, and J. J. Valiente-Dobón
Published: 2023

18. VADER: A novel decay station for actinide spectroscopy

Author: A. Raggio, I. Pohjalainen, E. Rey-Herme, O. Beliuskina, J. Bequet, M. Block, T. Eronen, A. Illana, A. Jaries, A. Kankainen, D. Kumar, I.D. Moore, M. Mougeot, A.M. Plaza, M. Reponen, J. Sarén, B. Sulignano, M. Stryjczyk, D. Thisse, M. Vandebrouck, and J. Warbinek
Subjects: Nuclear and High Energy Physics, actinides, alpha decay, decay spectroscopy, tutkimuslaitteet, spektroskopia, Decay spectroscopy, Actinides, Gamma spectroscopy, conversion electrons, gamma spectroscopy, ddc:530, Conversion electrons, Alpha decay, ydinfysiikka, Instrumentation
Abstract: Nuclear instruments & methods in physics research / B 540, 148 - 150 (2023). doi:10.1016/j.nimb.2023.04.021, Published by Elsevier, Amsterdam [u.a.]
Published: 2023
Full Text: View/download PDF

19. New collective structures in Au179 and their implications for the triaxial deformation of the Pt178 core

Author: M. Balogh, E. Jajčišinová, M. Venhart, A. Herzáň, J. L. Wood, D. T. Joss, F. A. Ali, K. Auranen, S. Bánovská, M. Bírová, R. J. Carroll, D. M. Cox, J. G. Cubiss, T. Davis, M. C. Drummond, P. T. Greenlees, T. Grahn, A. Gredley, J. Henderson, U. Jakobsson, R. Julin, S. Juutinen, G. Kantay, J. Konki, P. Konopka, M. Leino, V. Matoušek, A. K. Mistry, C. G. McPeake, D. O'Donnell, R. D. Page, J. Pakarinen, P. Papadakis, J. Partanen, P. Peura, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, B. Saygı, M. Sedlák, D. Seweryniak, C. Scholey, J. Sorri, A. Špaček, S. Stolze, M. Taylor, A. Thornthwaite, J. Uusitalo, M. Veselský, S. Vielhauer, and F. P. Wearing
Published: 2022

20. Refined description of the positive-parity bands and the extent of octupole correlations in Ba-120

Author: B. F. Lv, C. M. Petrache, K. K. Zheng, Z. H. Zhang, W. Sun, Z. P. Li, X. T. He, J. Zhang, A. Astier, P. Greenlees, T. Grahn, R. Julin, S. Juutinen, M. Luoma, J. Ojala, J. Pakarinen, J. Partanen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, H. Tann, J. Uusitalo, G. Zimba, B. Cederwall, Ö. Aktas, A. Ertoprak, W. Zhang, S. Guo, M. L. Liu, H. J. Ong, Z. Y. Sun, J. G. Wang, X. H. Zhou, I. Kuti, B. M. Nyakó, D. Sohler, J. Timár, C. Andreoiu, M. Doncel, D. T. Joss, and R. D. Page
Published: 2022

21. Nanosecond-Scale Proton Emission from Strongly Oblate-Deformed Lu149

Author: K. Auranen, A. D. Briscoe, L. S. Ferreira, T. Grahn, P. T. Greenlees, A. Herzáň, A. Illana, D. T. Joss, H. Joukainen, R. Julin, H. Jutila, M. Leino, J. Louko, M. Luoma, E. Maglione, J. Ojala, R. D. Page, J. Pakarinen, P. Rahkila, J. Romero, P. Ruotsalainen, M. Sandzelius, J. Sarén, A. Tolosa-Delgado, J. Uusitalo, and G. Zimba
Subjects: General Physics and Astronomy
Published: 2022

22. Candidate revolving chiral doublet bands in $${}^{119}$$Cs

Author: K. K. Zheng, C. M. Petrache, Z. H. Zhang, A. Astier, B. F. Lv, P. T. Greenlees, T. Grahn, R. Julin, S. Juutinen, M. Luoma, J. Ojala, J. Pakarinen, J. Partanen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, H. Tann, J. Uusitalo, G. Zimba, B. Cederwall, Ö. Aktas, A. Ertoprak, W. Zhang, S. Guo, M. L. Liu, X. H. Zhou, I. Kuti, B. M. Nyakó, D. Sohler, J. Timár, C. Andreoiu, M. Doncel, D. T. Joss, and R. D. Page
Subjects: Nuclear and High Energy Physics
Published: 2022

23. Position sensitive plastic scintillator for beta particle detection

Author: H. Joukainen, J. Sarén, and P. Ruotsalainen
Subjects: Nuclear and High Energy Physics, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, beetasäteily, recoil-beta tagging, tutkimuslaitteet, 01 natural sciences, plastic scintillator, ilmaisimet, 0103 physical sciences, 010306 general physics, ydinfysiikka, Instrumentation, decay tagging
Abstract: A new segmented plastic scintillator detector Tuike has been developed for recoil-beta tagging experiments at the Accelerator Laboratory of the University of Jyväskylä. The detector consists of individual plastic scintillator bars arranged in two orthogonal layers, and the scintillation light is detected using silicon photomultipliers. Performance of the new detector was tested using fusion-evaporation reaction 40Ca(36Ar, pn)74Rb, and the results are discussed here. It was found that for beta particles seen in the main silicon detector, Tuike can tag high-energy beta particles with a 48(10)% efficiency. An energy calibration method using Compton edges of gamma ray transitions is described in the present work. Tuike was demonstrated to improve the sensitivity to identify weak fusion-evaporation channels associated with beta decays having high beta end-point energy, enabling nuclear structure studies along the N = Z line. peerReviewed
Published: 2022

24. Experimental observation of the M1 scissors mode in $^{254}No$

Author: F.L. Bello Garrote, A. Lopez-Martens, A.C. Larsen, I. Deloncle, S. Péru, F. Zeiser, P.T. Greenlees, B.V. Kheswa, K. Auranen, D.L. Bleuel, D.M. Cox, L. Crespo Campo, F. Giacoppo, A. Görgen, T. Grahn, M. Guttormsen, T.W. Hagen, L. Harkness-Brennan, K. Hauschild, G. Henning, R.-D. Herzberg, R. Julin, S. Juutinen, T.A. Laplace, M. Leino, J.E. Midtbø, V. Modamio, J. Pakarinen, P. Papadakis, J. Partanen, T. Renstrøm, K. Rezynkina, M. Sandzelius, J. Sarén, C. Scholey, S. Siem, J. Sorri, S. Stolze, J. Uusitalo, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CEA DAM ILE-DE-FRANCE - Bruyères-le-Châtel [Arpajon] (CEA DAM IDF), Département Recherches Subatomiques (DRS-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, scissors mode, transfermium nuclides, γ-strength function, ddc:530, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ydinfysiikka
Abstract: Physics letters / B 834, 137479 (2022). doi:10.1016/j.physletb.2022.137479, Published by North-Holland Publ., Amsterdam
Published: 2022

25. Identification of excited states in Te5552107

Author: W. Zhang, B. Cederwall, C. Qi, A. Ertoprak, Ö. Aktas, X. Liu, K. Andgren, K. Auranen, T. Bäck, L. Barber, G. Beeton, D. M. Cullen, I. G. Darby, M. R. Dimmock, S. Eeckhaudt, E. Ganioğlu, M. Górska, T. Grahn, P. T. Greenlees, B. Hadinia, E. Ideguchi, A. Illana, P. M. Jones, D. T. Joss, R. Julin, S. Juutinen, J. M. Keatings, A. Khaplanov, F. Kulali, M. Leino, M. Luoma, B. Lv, B. S. Nara Singh, L. Nelson, M. Niikura, M. Nyman, J. Ojala, R. D. Page, J. Pakarinen, E. S. Paul, C. Petrache, M. Petri, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. F. Smith, J. Sorri, H. Tann, G. Zimba, J. Uusitalo, R. Wadsworth, and R. Wyss
Subjects: 010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, 01 natural sciences
Published: 2021

26. First investigation on the isomeric ratio in multinucleon transfer reactions: Entrance channel effects on the spin distribution

Author: D. Kumar, T. Dickel, A. Zadvornaya, O. Beliuskina, A. Kankainen, P. Constantin, S. Purushothaman, A. Spataru, M. Stryjczyk, L. Al Ayoubi, M. Brunet, L. Canete, C. Delafosse, R.P. de Groote, A. de Roubin, T. Eronen, Z. Ge, W. Gins, C. Hornung, M. Hukkanen, A. Illana, A. Jokinen, D. Kahl, B. Kindler, B. Lommel, I. Mardor, I.D. Moore, D.A. Nesterenko, D. Nichita, S. Nikas, A. Ortiz-Cortes, H. Penttilä, Zs. Podolyák, I. Pohjalainen, A. Raggio, M. Reponen, S. Rinta-Antila, J. Romero, J. Saren, M. Vilen, V. Virtanen, A. Weaver, and J. Winfield
Subjects: Multinucleon transfer (MNT) reaction, Isomeric-to-ground state ratio (IR), Gas-filled stopping cells, α-spectra, Physics, QC1-999
Abstract: The multinucleon transfer (MNT) reaction approach was successfully employed for the first time to measure the isomeric ratios (IRs) of 211Po isomer (25/2+) and its ground state (9/2+) at the IGISOL facility using a 945 MeV 136Xe beam impinged on 209Bi and natPb targets. The dominant production of isomers compared to the corresponding ground states was consistently revealed in the α-decay spectra. Deduced IR of 211Po populated through the 136Xe+natPb reaction was found to have an enhancement of ≈1.8-times than that observed for the 136Xe+209Bi. State-of-the-art Langevin-type model calculations have been utilized to estimate the spin distribution of an MNT residue. The computations qualitatively corroborate with the considerable increase in the IRs of 211Po produced from 136Xe+natPb compared to 136Xe+209Bi. Theoretical investigations indicate a weak dependence of target spin on the IRs. The enhancement of the 211Po isomer in the 136Xe+natPb over 136Xe+209Bi can be attributed to the different proton (p)-transfer production routes. Estimations demonstrate an increment in the angular momentum transfer, favorable for isomer production, with increasing projectile energy. Comparative analysis reveals the two entrance channel parameters, projectile mass and p-transfer channels, strongly influencing the population of the high-spin isomer of 211Po (25/2+). This letter reports the first experimental and theoretical study on the IRs of nuclei formed from two different p-transfer channels via two independent MNT reactions.
Published: 2024
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27. Backbending in the pear shaped 223 90 Th: evidence of a high spin octupole to quadrupole shape transition in the actinides

Author: G. Maquart, A. Astier, L. Augey, L. Chaix, I. Companis, C. Ducoin, J. Dudouet, D. Guinet, G. Lehaut, C. Mancuso, M.-G. Porquet, N. Redon, O. Stézowski, A. Vancraeyenest, C. Beck, S. Courtin, D. Curien, D. S. Delion, I. Deloncle, T. Grahn, P. Greenlees, A. Herzan, K. Hauschild, U. Jakobsson, P. Jones, R. Julin, S. Juutinen, S. Ketelhut, M. Leino, A. Lopez-Martens, P. Nieminen, P. Petkov, P. Peura, P. Rahkila, S. Rinta-Antila, P. Ruotsalainen, M. Sandzelius, J. Sarén, P. Schuck, C. Scholey, J. Sorri, S. Stolze, and J. Uusitalo
Published: 2016
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28. A Recoil-Beta Tagging Study of N = Z nucleus [sup 66]As

Author: P. Ruotsalainen, C. Scholey, R. Wadsworth, D. G. Jenkins, B. S. Nara Singh, T. S. Brock, P. T. Greenlees, U. Jakobsson, P. Jones, R. Julin, S. Juutinen, S. Ketelhut, M. Leino, N. M. Lumley, P. J. R. Mason, P. Nieminen, M. Nyman, I. Paterson, P. Peura, M. G. Procter, P. Rahkila, J. Sarén, J. Sorri, J. Uusitalo, Paraskevi Demetriou, Rauno Julin, and Sotirios Harissopulos
Subjects: Nuclear reaction, Physics, Nuclear physics, Recoil, Spectrometer, Excited state, Neutron, Gamma spectroscopy, Isotopes of silicon, Atomic physics, Nuclear Experiment, Radioactive decay
Abstract: A Recoil‐Beta Tagging (RBT) experiment was recently performed at the accelerator laboratory at the University of Jyvaskyla in order to identify T = 1 excited states in the medium‐heavy N = Z = 33 nucleus 66As. The fusion‐evaporation reaction 28Si(40Ca,pn)66As was employed at a beam energy of 75 MeV. The experiment was carried out utilising the JUROGAM II γ‐ray spectrometer in conjunction with the gas‐filled recoil separator RITU and the GREAT focal plane spectrometer system. The half‐lives and ordering of the two known isomeric states in 66As have been determined. In addition, several new prompt γ‐ray transitions from excited states both bypassing and decaying to the isomeric states in 66As have been observed.
Published: 2011

29. Lifetime measurement in the proton-unbound nucleus [sup 109]I

Author: M. G. Procter, D. M. Cullen, P. Ruotsalainen, C. Scholey, L. Angus, T. Bäck, B. Cederwall, A. Dewald, C. Fransen, T. Grahn, P. T. Greenlees, M. Hackstein, U. Jakobsson, P. M. Jones, R. Julin, S. Juutinen, S. Ketelhut, M. Leino, N. M. Lumley, P. J. R. Mason, P. Nieminen, M. Nyman, J. Pakarinen, T. Pissulla, P. Peura, P. Rahkila, J. Revill, S. V. Rigby, W. Rother, M. Sandzelius, J. Sarén, J. Sorri, M. J. Taylor, J. Uusitalo, P. Wady, C. Qi, F. R. Xu, and Bertram Blank
Subjects: Nuclear physics, Physics, Valence (chemistry), medicine.anatomical_structure, ta114, Excited state, Nuclear Theory, SHELL model, medicine, Atomic physics, Nuclear Experiment, Nucleon, Nucleus
Abstract: The Recoil‐Distance Doppler‐shift method has been combined with Recoil‐Decay Tagging for the first time to measure a lifetime in the proton‐unbound nucleus 109I. The lifetime value was determined using the Differential Decay‐Curve method in singles mode. The result has been compared to theoretical shell‐model calculations in order to better understand the nature of unbound valence nucleons at the proton drip line.
Published: 2011

30. Nuclear Structure at the Extremes; In-beam γ-ray Spectroscopy of [sup 180]Pb

Author: J. Pakarinen, P. Rahkila, D. G. Jenkins, C. Gray-Jones, P. T. Greenlees, U. Jakobsson, P. Jones, R. Julin, S. Juutinen, S. Ketelhut, H. Koivisto, M. Leino, P. Nieminen, M. Nyman, P. Papadakis, S. Paschalis, M. Petri, P. Peura, O. Roberts, T. Ropponen, P. Ruotsalainen, J. Sarén, C. Scholey, J. Sorri, A. G. Tuff, J. Uusitalo, R. Wadsworth, M. Bender, P.-H. Heenen, Paraskevi Demetriou, Rauno Julin, and Sotirios Harissopulos
Subjects: Nuclear physics, Physics, Proton, Excited state, Nuclear Theory, Nuclear structure, Neutron, Gamma spectroscopy, Alpha decay, Atomic physics, Nuclear Experiment, Nucleon, Radioactive decay
Abstract: For the first time, the excited states in the extremely neutron‐deficient nucleus 180Pb have been observed in an in‐beam γ‐ray measurement employing the recoil‐decay tagging technique. Deduced level energies follow the trend of prolate intruder band level energies derived from heavier lead isotopes and reflect the persistence of magicity of the closed Z = 82 proton shell when approaching the proton drip line.
Published: 2011

31. Investigation of 246Fm : in‐beam spectroscopy at the limits

Author: J. Piot, O. Dorvaux, B. J.-P. Gall, P. T. Greenlees, L. L. Andersson, D. M. Cox, F. Dechery, T. Grahn, K. Hauschild, G. Henning, A. Herzan, R.-D. Herzberg, F. P. Heßberger, U. Jakobsson, P. Jones, R. Julin, S. Juutinen, S. Ketelhut, T.-L. Khoo, M. Leino, J. Ljungvall, A. Lopez-Martens, P. Nieminen, P. Papadakis, E. Parr, P. Peura, P. Rahkila, S. Rinta-Antila, J. Rubert, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, D. Seweryniak, J. Sorri, B. Sulignano, C. Theisen, J. Uusitalo, Paraskevi Demetriou, Rauno Julin, Sotirios Harissopulos, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Département de Physique Nucléaire (ex SPhN) (DPHN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear reaction, Physics, 010501 environmental sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010403 inorganic & nuclear chemistry, 01 natural sciences, Quasi particles, 0104 chemical sciences, Nuclear physics, Gamma spectroscopy, Rotational spectroscopy, Spectroscopy, Beam (structure), 0105 earth and related environmental sciences
Abstract: International audience; The structure of 246Fm has been investigated using in‐beam γ‐ray spectroscopy. The experiment was performed at the University of Jyväskylä using JUROGAM 2 coupled to RITU and GREAT. The 246Fm nuclei were produced using a 186 MeV beam of 40Ar impinging on a target of 208Pb. JUROGAM 2 was fully instrumented with TNT2D digital acquisition cards. The use of digital acquisition cards and a rotating target allowed for unprecedented beam intensities up to 71 particle‐nanoamperes for prompt γ‐ray spectroscopy. With all these major advances for spectroscopy a rotational band is observed for the first time in 246Fm and discussed here. © 2011 American Institute of Physics
Published: 2010

32. First observation of excited states inHg172

Author: M. Sandzelius, E. Ganioğlu, B. Cederwall, B. Hadinia, K. Andgren, T. Bäck, T. Grahn, P. Greenlees, U. Jakobsson, A. Johnson, P. M. Jones, R. Julin, S. Juutinen, S. Ketelhut, A. Khaplanov, M. Leino, M. Nyman, P. Peura, P. Rahkila, J. Sarén, C. Scholey, J. Uusitalo, and R. Wyss
Subjects: Physics, Nuclear and High Energy Physics, Stable isotope ratio, Neutron emission, Yrast, Excited state, Dirac (software), Quasiparticle, Atomic physics, Random phase approximation, Spectral line
Abstract: Excited states in the extremely neutron-deficient isotope {sup 172}Hg have been established for the first time. The {sup 96}Ru({sup 78}Kr,2n) reaction was employed to populate excited states in {sup 172}Hg with a cross section {sigma}{approx_equal}15 nb. The highly selective recoil-decay tagging (RDT) technique was used to obtain clean in-beam {gamma}-ray spectra for {sup 172}Hg. The yrast ground-state band has tentatively been established up to I=6 ({Dirac_h}/2{pi}). The data have been interpreted within the framework of total Routhian surface and quasiparticle random phase approximation calculations.
Published: 2009

33. Gamma-Ray Spectroscopy at the Limits: First Observation of Rotational Bands in 255Lr

Author: S, Ketelhut, P T, Greenlees, D, Ackermann, S, Antalic, E, Clément, I G, Darby, O, Dorvaux, A, Drouart, S, Eeckhaudt, B J P, Gall, A, Görgen, T, Grahn, C, Gray-Jones, K, Hauschild, R-D, Herzberg, F P, Hessberger, U, Jakobsson, G D, Jones, P, Jones, R, Julin, S, Juutinen, T-L, Khoo, W, Korten, M, Leino, A-P, Leppänen, J, Ljungvall, S, Moon, M, Nyman, A, Obertelli, J, Pakarinen, E, Parr, P, Papadakis, P, Peura, J, Piot, A, Pritchard, P, Rahkila, D, Rostron, P, Ruotsalainen, M, Sandzelius, J, Sarén, C, Scholey, J, Sorri, A, Steer, B, Sulignano, Ch, Theisen, J, Uusitalo, M, Venhart, M, Zielinska, M, Bender, P-H, Heenen, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 21.10.Re, 23.20.Lv, 27.90.+b
Abstract: The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2;{-}[521] and 7/2;{-}[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.
Published: 2009

34. Lifetime Measurements and Coulomb Excitation of Light Hg Nuclei

Author: A. Petts, P. A. Butler, T. Grahn, A. Blazhev, N. Bree, B. Bruyneel, J. Cederkäll, E. Clement, T. E. Cocolios, A. Dewald, J. Eberth, L. Fraile, C. Fransen, M. B. Gómez Hornillos, P. T. Greenlees, A. Görgen, M. Guttormsen, K. Hadynska, K. Helariutta, R.-D. Herzberg, M. Huyse, D. G. Jenkins, J. Jolie, P. Jones, R. Julin, S. Juutinen, S. Ketelhut, S. Knapen, T. Kröll, R. Krücken, A. C. Larsen, M. Leino, J. Ljungvall, P. Maierbeck, P. L. Marley, B. Melon, P. J. Napiorkowski, M. Nyman, R. D. Page, J. Pakarinen, G. Pascovici, N. Patronis, P. J. Peura, E. Piselli, Th. Pissulla, P. Rahkila, P. Reiter, J. Sarén, M. Scheck, C. Scholey, A. Semchenkov, S. Siem, I. Stefanescu, J. Sorri, J. Uusitalo, J. Van de Walle, P. Van Duppen, D. Voulot, R. Wadsworth, N. Warr, D. Weisshaar, F. Wenander, M. Zielinska, Jan Jolie, Andreas Zilges, Nigel Warr, Andrey Blazhev, Blazhev, A, Jolie, J, Warr, N, and Zilges, A
Subjects: Physics, Coulomb excitation, Yrast, shape coexistence, Hg, Preliminary analysis, Nuclear physics, symbols.namesake, Recoil, Nucleosynthesis, Recoil distance Doppler-shift, lifetimes, symbols, Atomic physics, Nuclear Experiment, Doppler effect, Radioactive decay
Abstract: Two complementary experimental programs have taken place to investigate the origin and evolution of shape coexistence in the light mercury region. Recoil Distance Doppler-shift measurements were performed at the University of Jyvaskyla utilizing the Koln plunger device in conjunction with the JUROGAM + RITU + GREAT setup. In addition, Coulomb excitation measurements of 184,186,188Hg were performed at REX-ISOLDE using the MINIBALL Ge-detector array. The results of the lifetime measurements of the yrast states up to I^{\pi} = 10+ in 182Hg are reported. Preliminary analysis of the Coulomb excitation data is also discussed. ispartof: pages:414-418 ispartof: AIP Conference Proceedings vol:1090 pages:414-418 ispartof: Capture gamma-ray spectroscopy and related topics location:Koln, Germany date:25 Aug - 28 Aug 2008 status: published
Published: 2009

35. Spectroscopy of odd-proton nuclei in the region of [sup 254]No

Author: S. Ketelhut, P. T. Greenlees, A. Chatillon, E. Bouchez, P. A. Butler, E. Clément, O. Dorvaux, S. Eeckhaudt, B. J. P. Gall, A. Görgen, T. Grahn, R.-D. Herzberg, F. Heβberger, A. Hürstel, P. Jones, R. Julin, S. Juutinen, H. Kettunen, F. Khalfallah, W. Korten, Y. Le Coz, M. Leino, A.-P. Leppänen, S. Moon, P. Nieminen, M. Nyman, J. Pakarinen, J. Perkowski, P. Rahkila, M. Rousseau, J. Sarén, C. Scholey, Ch. Theisen, J. Uusitalo, J. N. Wilson, P. Bonche, P.-H. Heenen, P. Demetriou, and S. V. Harissopulos
Subjects: Physics, Nuclear physics, medicine.anatomical_structure, Proton, chemistry, medicine, Nuclear structure, chemistry.chemical_element, Germanium, Gamma spectroscopy, Atomic physics, Spectroscopy, Nucleus
Abstract: Two rotational bands have been found in the transfermium nuclei 251Md and 255Lr, the latter being the heaviest nucleus so far studied in‐beam. Both are assigned to a [521]1/2− Nilsson state by comparison to theory. The experiments have been carried out in the Accelerator Laboratory of the University of Jyvaskyla (JYFL), where the array of germanium detectors JUROGAM was used in conjunction with the recoil‐seperator RITU and the focal‐plane setup GREAT for gamma‐spectroscopic studies.
Published: 2008

36. Probing collectivity in the vicinity of neutron deficient Pb nuclei

Author: T. Grahn, A. Dewald, M. B. Gómez Hornillos, P. T. Greenlees, A. Görgen, K. Helariutta, J. Jolie, P. Jones, R. Julin, S. Juutinen, S. Ketelhut, R. Krücken, T. Kröll, M. Leino, J. Ljungvall, P. Maierbeck, B. Melon, M. Nyman, R. D. Page, A. Petts, Th. Pissulla, P. Rahkila, J. Sarén, C. Scholey, J. Sorri, J. Uusitalo, R. Wadsworth, M. Zielińska, P. Demetriou, and S. V. Harissopulos
Subjects: Physics, Recoil, Excited state, Nuclear Theory, Oblate spheroid, Nuclear structure, Electromagnetic devices, Neutron, Prolate spheroid, Atomic physics, Nuclear Experiment
Abstract: A series of recoil distance Doppler‐shift lifetime measurements have been carried out to probe collectivity and configuration mixing of different shapes in the vicinity of neutron mid‐shell Pb nuclei. Lifetime measurements of 186Pb and 194Po, the first ever utilizing the recoil‐decay tagging method, probed the collectivity of coexisting prolate and oblate shapes in this region. Futher lifetime measurements of excited states in 180Hg, 182Hg and 196Po have been carried out.
Published: 2008

37. Spectroscopy of Very Heavy Elements

Author: P. T. Greenlees, R.-D. Herzberg, S. Ketelhut, D. Ackermann, P. A. Butler, A. Chatillon, S. Eeckhaudt, B. J. P. Gall, T. Grahn, C. Gray-Jones, A. Görgen, F.-P. Heβberger, U. Jakobsson, G. D. Jones, P. Jones, R. Julin, S. Juutinen, T.-L. Khoo, W. Korten, M. Leino, S. Moon, M. Nyman, J. Pakarinen, P. Papadakis, P. Peura, P. Rahkila, M. Richer, D. Rostron, C. Santos, J. Sarén, C. Scholey, J. Sorri, S. K. Tandel, Ch. Theisen, J. Uusitalo, M. Venhart, P. Demetriou, and S. V. Harissopulos
Published: 2008

38. Decays of new nuclides and isomers beyond the proton drip line - The influence of neutron configurations

Author: R. D. Page, L. Bianco, I. G. Darby, D. T. Joss, J. Simpson, J. S. Al-Khalili, A. J. Cannon, R. J. Cooper, S. Eeckhaudt, S. Ertürk, B. Gall, T. Grahn, P. T. Greenlees, B. Hadinia, P. M. Jones, D. S. Judson, R. Julin, S. Juutinen, S. Ketelhut, M. Labiche, M. Leino, A.-P. Leppänen, M. Nyman, D. O’Donnell, P. Rahkila, P. J. Sapple, J. Sarén, C. Scholey, A. N. Steer, P. D. Stevenson, E. B. Suckling, J. Thomson, J. Uusitalo, M. Venhart, Ismail Boztosun, A. B. Balantekin, 0-Belirlenecek, and Page, R.D., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Bianco, L., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Darby, I.G., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Joss, D.T., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Simpson, J., STFC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom -- Al-Khalili, J.S., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Cannon, A.J., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Cooper, R.J., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Eeckhaudt, S., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Ertürk, S., Nigde Universitesi, Fen-Edebiyat Falkultesi, Fizik Bdlumti, Nigde, Turkey -- Gall, B., IPHC, CNRS, IN2P3, ULP Strasbourg, 23 rue de Loess, Strasbourg, 67037, France -- Grahn, T., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Greenlees, P.T., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Hadinia, B., Royal Institute of Technology, Alba Nova Center, Stockholm, S-106 91, Sweden -- Jones, P.M., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Judson, D.S., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Julin, R., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Juutinen, S., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Ketelhut, S., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Labiche, M., STFC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom -- Leino, M., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Leppänen, A.-P., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Nyman, M., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- O'Donnell, D., STFC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom -- Rahkila, P., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Sapple, P.J., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Sarén, J., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Scholey, C., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Steer, A.N., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Stevenson, P.D., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Suckling, E.B., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Thomson, J., Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Uusitalo, J., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland -- Venhart, M., Department of Physics, University of Jyvdskyld, Jyvdskyld, FIN-40014, Finland
Subjects: Physics, Proton, Gamma ray, Alpha particle, Segmented Si and Ge detectors. Measured E ? ,E proton ,E ? ,T 1/2, Nuclear physics, Nuclear Reactions 58 Ni+ 106 Cd at 290,300,310 MeV beam energy, Beta particle, Neutron, Enriched targets, Nuclide, Alpha decay, Gas-filled recoil separator, Atomic physics, Nuclear Experiment, Ground state
Abstract: Bozok University;Erciyes University;et al.;Istanbul University;Nigde University;The Turkish Atomic Energy Authority (TAEK), International Conference on Nuclear Physics and Astrophysics: From Stable Beams to Exotic Nuclei 2008 -- 25 June 2008 through 30 June 2008 -- -- 139817, The energy of the vh 9/2 orbital in nuclei above N = 82 drops rapidly in energy relative to the vf 7/2 orbital as the occupancy of the ?h 11/2 orbital increases. These two neutron orbitals become nearly degenerate as the proton drip line is approached. In this work, we have discovered the new nuclides 161 Os and 157 W, and studied the decays of the proton emitter 160 Re in detail. The 161 Os and 160 Re nuclei were produced in reactions of 290, 300 and 310 MeV 58 Ni ions with an isotopically enriched 106 Cd target, separated in-flight using the RITU separator and implanted into the GREAT spectrometer. The 161 Os a decays populated the new nuclide 157 W, which decayed by ß-particle emission. The ß decay fed the known ?-decaying l/2 + and 11/2 - states in 157 Ta, which is consistent with a vf 7/2 ground state in 157 W. The measured a-decay energy and half-life for 161 Os correspond to a reduced ?-decay width that is compatible with s-wave ?-particle emission, implying that its ground state is also a vf 7/2 state. Over 7000 160 Re nuclei were produced and the y decays of a new isomeric state feeding the ?d 3/2 level in 160 Re were discovered, but no evidence for the proton or a decay of the expected ?h 11/2 state could be found. The isomer decays offer a natural explanation for this non-observation and provides a striking example of the influence of the near degeneracy of the vh 9/2 and vf 7/2 orbitals on the properties of nuclei in this region. © 2008 American Institute of Physics., Academy of Finland Science and Technology Facilities Council Finnish Centre of Excellence in Atomic Layer Deposition Natural Sciences and Engineering Research Council of Canada, We would like to thank the technical staff at Jyvaskyla for their excellent support and to Paul Morrall from Daresbury Laboratory for making the targets. This work has been supported by the UK Science and Technology Facilities Council; the Swedish Natural Science Research Council; the Academy of Finland under the Finnish Centre of Excellence Programme (project 44875 Nuclear and Condensed Matter Physics Programme at JYFL); the European Union Sixth Framework contract EURONS (RII3-CT-2004-506065) and the European Union Marie Curie Programme (contract HPMT-CT-2001-00250).
Published: 2008

39. Discovery of the proton emitting nucleus $^{159}$Re

Author: D. T. Joss, I. G. Darby, R. D. Page, J. Uusitalo, S. Eeckhaudt, T. Grahn, P. T. Greenlees, P. M. Jones, R. Julin, S. Juutinen, S. Ketelhut, M. Leino, A.-P. Leppänen, M. Nyman, J. Pakarinen, P. Rahkila, J. Sarén, C. Scholey, A. N. Steer, J. S. Al-Khalili, A. J. Cannon, P. D. Stevenson, S. Ertürk, B. Gall, B. Hadinia, M. Venhart, J. Simpson, Lídia S. Ferreira, Paramasivan Arumugan, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Lídia S. Ferreira, Paramasivan Arumugan, Joss, D.T., Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom, STFC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom -- Darby, I.G., Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Page, R.D., Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Uusitalo, J., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Eeckhaudt, S., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Grahn, T., Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Greenlees, P.T., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Jones, P.M., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Julin, R., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Juutinen, S., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Ketelhut, S., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Leino, M., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Leppänen, A.-P., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Nyman, M., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Pakarinen, J., Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, United Kingdom -- Rahkila, P., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Sarén, J., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Scholey, C., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Steer, A.N., Department of Physics, University of Jyväskylä, PO Box 35, FIN-40014, Jyväskylä, Finland -- Al-Khalili, J.S., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Cannon, A.J., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Stevenson, P.D., Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom -- Ertürk, S., Nigde Universitesi, Fen-Edebiyat Falkültesi, Fizik Bölümü, Nigde, Turkey -- Gall, B., ULP Strasbourg, 23 rue du Loess, 67037 Strasbourg Cedex 2, France -- Hadinia, B., Department of Physics, Royal Institute of Technology, SE-10691, Stockholm, Sweden -- Venhart, M., Department of Nuclear Physics and Biophysics, Comenius University, Mlynska Dolina, 842 48, Bratislava 4, Slovakia -- Simpson, J., STFC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom, and 0-Belirlenecek
Subjects: Si detectors, nuclear spin, Measured E p, Proton, Hadron, 02 engineering and technology, rhenium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Nuclear physics, Isotopes of cadmium, 0202 electrical engineering, electronic engineering, information engineering, nuclei with mass number 150 to 189, Enriched targets, radioactive decay periods, Nuclide, Isotope, Chemistry, Nuclear structure, 020206 networking & telecommunications, T1/2, 13. Climate action, 020201 artificial intelligence & image processing, 23.50.+z, 27.70.+q, 21.10.Tg, 21.10.Hw, Gas-filled recoil separator, Nucleon, Radioactive decay, Nuclear reactions 58Ni + 106Cd at 300 MeV beam energy, proton emission decay
Abstract: Fund. para Cienc. Tecnol., FCT, Minist. Cienc. Tecnol.;Fundacao Calouste Gulbenkian;Fundacao Luso-Americana, International Conference on Proton Emitting Nuclei and Related Topics, PROCON 2007 -- 17 June 2007 through 23 June 2007 -- Lisbon, The observation of the new nuclide 159Re provides important insights into the evolution of single-particle structure in heavy nuclei beyond the proton drip line. The nuclide 159Re was synthesised in the reaction 106Cd(58Ni, p4n) and identified via its proton radioactivity using the RITU gas-filled separator and the GREAT focal-plane spectrometer. Comparisons of the measured proton energy (Ep = 1805±20 keV) and decay half-life (t1/2 = 21±4 µs) with values calculated using the WKB method indicate that the proton is emitted from an h11/2 state. The implications of these results for future experimental investigations into even more proton unbound Re isotopes using in-flight separation techniques are considered. © 2007 American Institute of Physics.
Published: 2007

40. Probing single-particle structures beyond the proton drip line

Author: R. D. Page, L. Bianco, I. G. Darby, D. T. Joss, T. Grahn, R.-D. Herzberg, J. Pakarinen, J. Thomson, J. Uusitalo, S. Eeckhaudt, P. T. Greenlees, P. M. Jones, R. Julin, S. Juutinen, S. Ketelhut, M. Leino, A.-P. Leppänen, M. Nyman, P. Rahkila, J. Sarén, C. Scholey, A. Steer, M. Venhart, J. Simpson, J. S. Al-Khalili, A. J. Cannon, P. D. Stevenson, S. Ertürk, B. Gall, B. Hadinia, Lídia S. Ferreira, Paramasivan Arumugan, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Lídia S. Ferreira, Paramasivan Arumugan, Ferreira, LS, Arumugam, P, Scholey, Catherine -- 0000-0002-8743-6071, Stevenson, Paul -- 0000-0003-2645-2569, Pakarinen, Janne -- 0000-0001-8944-8757, Grahn, Tuomas -- 0000-0002-6255-2279, Jones, Pete -- 0000-0001-7480-6603, and [Page, R. D. -- Bianco, L. -- Darby, I. G. -- Joss, D. T. -- Grahn, T. -- Herzberg, R. -D. -- Pakarinen, J. -- Thomson, J.] Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England -- [Uusitalo, J. -- Eeckhaud, S. -- Greenlees, P. T. -- Jones, P. M. -- Julin, R. -- Juutinen, S. -- Ketelhut, S. -- Leino, M. -- Leppanen, A. -P. -- Nyman, M. -- Rahkila, P. -- Saren, J. -- Scholey, C. -- Steer, A. -- Venhart, M.] Univ jyvaskyla, Dept Phys, FIN-40014 Jyvaskyla, Finland -- [Simpson, J.] STFC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England -- [Al-Khalili, J. S. -- Cannon, A. J. -- Stevenson, P. D.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England -- [Erturk, S.] Nigde Univ, Nigde, Turkey -- [Gall, B.] ULP Strasbourg, CNRS IN2P, IPHC, F-67037 Strasbourg 2, France -- [Hadinia, B.] AlbaNova Univ Ctr, Royal Inst Technol, S-10691 Stockholm, Sweden
Subjects: Proton, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, nuclei with mass number 150 to 189, Neutron, alpha-decay, radioactive decay periods, Proton emission, branching ratio. Re-159, 010306 general physics, Nuclear Experiment, Physics, RADIOACTIVITY Re-159(alpha)[from Cd-106(Ni-58,p4n)], Ta-155 deduced levels, Ta-155(p)[from Re-159 a decay], 010308 nuclear & particles physics, Alpha particle, previous Ta-155 study, Charged particle, comparisons with neighbouring nuclides, measured E-alpha, E-p, T-1/2, 23.50.+z, 23.60.+e, 27.70.+q, J, pi configurations, Alpha decay, Atomic physics, Nucleon, Radioactive decay, proton emission decay
Abstract: International Conference on Proton Emitting Nuclei and Related Topics -- JUN 17-23, 2007 -- Lisbon, PORTUGAL, WOS: 000252267300021, Single-particle energies have been investigated in the closed neutron shell proton emitter Ta-155. The Ta-155 nuclei were populated through the alpha decay of Re-159, which has been observed for the first time. The (159)Rc nuclei were produced in reactions of 300 MeV Ni-58 ions with an isotopically enriched Cd-106 target, separated in-flight using the RITU separator and implanted into the GREAT spectrometer. The Re-159 a decay emanates from the proton-emitting pi h(11/2) state and populates a state in Ta-155 which decays by the emission of a proton from a pi h(11/2) orbital. The results fit in with the systematics of proton and alpha-particle separation energies in the region, but disagree with the previously reported decay properties of Ta-155., Fundacao Ciencia & Tecnol, Minist Ciencia & Tecnol, Fundacao Calouste Gulbenklan, Fundacao Luso Americana, UK Engineering and Physical Sciences Research Council; Swedish Natural Science Research Council; Academy of Finland under the Firmish Centre of Excellence Programme (project 44875 Nuclear and Condensed Matter Physics Programme at JYFL); European Union Sixth Framework contract EURONS [RII3-CT-2004-506065]; European Union Marie Curie Programme [HPMT-CT-2001-00250], The authors would like to thank the technical staff at the Accelerator Laboratory at the University of Jyvaskyla for their excellent support and to Paul Morrall from Daresbury Laboratory for making the targets. This work has been supported by the UK Engineering and Physical Sciences Research Council; the Swedish Natural Science Research Council; the Academy of Finland under the Firmish Centre of Excellence Programme (project 44875 Nuclear and Condensed Matter Physics Programme at JYFL); the European Union Sixth Framework contract EURONS (contract RII3-CT-2004-506065) and the European Union Marie Curie Programme (contract HPMT-CT-2001-00250).
Published: 2007

41. Evidence for enhanced collectivity in Te-I-Xe nuclei near the N = Z = 50 double shell closure

Author: B. Cederwall, B. Hadinia, M. Sandzelius, E. S. Paul, M. Petri, K. Andgren, E. Ganioălu, I. G. Darby, M. R. Dimmock, S. Eeckhaudt, T. Grahn, P. T. Greenlees, E. Ideguchi, P. M. Jones, D. T. Joss, R. Julin, S. Juutinen, A. Khaplanov, M. Leino, L. Nelson, M. Niikura, M. Nyman, R. D. Page, J. Pakarinen, P. Rahkila, J. Sarén, C. Scholey, J. Sorri, J. Uusitalo, R. Wadsworth, R. Wyss, Lídia S. Ferreira, and Paramasivan Arumugan
Subjects: Physics, Spectrometer, Phonon, Neutron number, Excited state, Neutron, Gamma spectroscopy, Nuclide, Atomic physics, Nuclear Experiment, Radioactive decay
Abstract: Gamma‐ray transitions have been identified for the first time in the extremely neutron‐deficient Tz = 1 nuclide 110Xe and the energies of the three lowest excited states in the ground‐state band have been deduced. A level scheme has also been constructed for the proton‐unbound, Tz = 3/2 nuclide 109I, exhibiting band structures built on g7/2 and h11/2 states in a weakly deformed, triaxial nucleus. In addition, a third band is proposed to be built on a g7/2 orbital coupled to an octupole‐vibrational phonon of the 108Te core. The results were obtained in a recoil‐decay tagging experiment using the 58Ni(54Fe,2n/p2n) reaction at a beam energy of 195 MeV. The experiment was performed using the highly efficient JUROGAM γ‐ray spectrometer in conjunction with the RITU gas‐filled recoil separator and the GREAT focal‐plane spectrometer. The results on 110Xe establish a breaking of the normal trend of increasing first excited 2+ and 4+ level energies as a function of decreasing neutron number as the N = 50 major shel...
Published: 2007

42. Spectroscopy of the very neutron-deficient [sup 189]Bi

Author: C. Dossat, Ch. Theisen, A. Bürger, E. Clément, A. Görgen, W. Korten, S. Eeckhaudt, P. Jones, T. Grahn, P. T Greenlees, R. Julin, S. Juutinen, M. Leino, A.-P. Leppänen, M. Nyman, J. Pakarinen, P. Rahkila, J. Sarén, C. Scholey, J. Sorri, J. Uusitalo, M. Venhart, Lídia S. Ferreira, and Paramasivan Arumugan
Subjects: Mass number, Physics, Proton, Isotope, Astrophysics::High Energy Astrophysical Phenomena, Physics::Atomic and Molecular Clusters, Nuclear structure, Neutron, Gamma spectroscopy, Alpha decay, Atomic physics, Nuclear Experiment, Spectroscopy
Abstract: The neutron‐deficient isotope 189Bi has been studied at the University of Jyvaskyla using alpha‐decay, isomer and prompt gamma‐ray spectroscopy. The structure of 189Bi can be understood by the coupling of an unpaired proton to the 188Pb core, in which spherical, prolate, and oblate shapes were found to coexist. Improved data on alpha‐decay and prompt gamma‐ray spectroscopy have been obtained, giving further insight into the shape coexistence phenomenon in the neutron‐deficient lead region.
Published: 2007

43. Collectivity and configuration mixing in 186,188Pb and 194Po

Author: T, Grahn, A, Dewald, O, Möller, R, Julin, C W, Beausang, S, Christen, I G, Darby, S, Eeckhaudt, P T, Greenlees, A, Görgen, K, Helariutta, J, Jolie, P, Jones, S, Juutinen, H, Kettunen, T, Kröll, R, Krücken, Y, Le Coz, M, Leino, A-P, Leppänen, P, Maierbeck, D A, Meyer, B, Melon, P, Nieminen, M, Nyman, R D, Page, J, Pakarinen, P, Petkov, P, Rahkila, B, Saha, M, Sandzelius, J, Sarén, C, Scholey, and J, Uusitalo
Abstract: Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |beta2|=0.29(5) and |beta2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.
Published: 2006

44. The influence of quasineutron configurations on 161Ta and nearby odd-A Nuclei

Author: D. T. Joss, K. Lagergren, J. Thomson, D. E. Appelbe, C. J. Barton, L. Bianco, B. Cederwall, I. G. Darby, T. Grahn, S. Eeckhaudt, S. Ertürk, M. B. Gomez-Hornillos, P. T. Greenlees, B. Hadinia, P. M. Jones, R. Julin, S. Juutinen, S. Ketelhut, H. Kettunen, M. Labiche, M. Leino, A.-P. Leppänen, P. Nieminen, M. Nyman, D. O'Donnell, R. D. Page, J. Pakarinen, E. S. Paul, J. Perkowski, P. Rahkila, M. Sandzelius, P. J. Sapple, J. Sarén, C. Scholey, J. Simpson, J. Sorri, J. Uusitalo, M. Venhart, D. D. Warner, D. R. Wiseman, R. Wyss, and Bertram Blank
Subjects: Physics, Proton, ta114, Yrast, Nuclear Theory, Nuclear structure, medicine.anatomical_structure, Atomic orbital, Quasiparticle, medicine, Neutron, Atomic physics, Nuclear Experiment, Nucleus, Line (formation)
Abstract: Several strongly coupled bands in the neutron‐deficient nucleus 161Ta have been identified and quasiparticle configuration assignments have been made on the basis of rotational alignments and cranked shell model calculations. The level scheme elucidated for 161Ta highlights the competition between the ν(h9/2) and ν(i13/2) orbitals to form the yrast spectrum. The band structures in 161Ta also provide new insights into the structural features of other heavy odd‐A nuclei populated with much lower reaction cross sections in this region at the proton drip line.
Published: 2011

45. Spectroscopic factor and proton formation probability for the d3/2 proton emitter 151mLu

Author: F. Wang, B.H. Sun, Z. Liu, R.D. Page, C. Qi, C. Scholey, S.F. Ashley, L. Bianco, I.J. Cullen, I.G. Darby, S. Eeckhaudt, A.B. Garnsworthy, W. Gelletly, M.B. Gomez-Hornillos, T. Grahn, P.T. Greenlees, D.G. Jenkins, G.A. Jones, P. Jones, D.T. Joss, R. Julin, S. Juutinen, S. Ketelhut, S. Khan, A. Kishada, M. Leino, M. Niikura, M. Nyman, J. Pakarinen, S. Pietri, Z. Podolyak, P. Rahkila, S. Rigby, J. Saren, T. Shizuma, J. Sorri, S. Steer, J. Thomson, N.J. Thompson, J. Uusitalo, P.M. Walker, S. Williams, H.F. Zhang, W.Q. Zhang, and L.H. Zhu
Subjects: Proton emitter, Recoil-decay tagging, Spectroscopic factor, Proton formation probability, WKB approximation, A=151, Physics, QC1-999
Abstract: The quenching of the experimental spectroscopic factor for proton emission from the short-lived d3/2 isomeric state in 151mLu was a long-standing problem. In the present work, proton emission from this isomer has been reinvestigated in an experiment at the Accelerator Laboratory of the University of Jyväskylä. The proton-decay energy and half-life of this isomer were measured to be 1295(5) keV and 15.4(8) μs, respectively, in agreement with another recent study. These new experimental data can resolve the discrepancy in the spectroscopic factor calculated using the spherical WKB approximation. Using the R-matrix approach it is found that the proton formation probability indicates no significant hindrance for the proton decay of 151mLu.
Published: 2017
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46. Nanosecond-Scale Proton Emission from Strongly Oblate-Deformed ^{149}Lu.

Author: Auranen K, Briscoe AD, Ferreira LS, Grahn T, Greenlees PT, Herzáň A, Illana A, Joss DT, Joukainen H, Julin R, Jutila H, Leino M, Louko J, Luoma M, Maglione E, Ojala J, Page RD, Pakarinen J, Rahkila P, Romero J, Ruotsalainen P, Sandzelius M, Sarén J, Tolosa-Delgado A, Uusitalo J, and Zimba G
Abstract: Using the fusion-evaporation reaction ^{96}Ru(^{58}Ni,p4n)^{149}Lu and the MARA vacuum-mode recoil separator, a new proton-emitting isotope ^{149}Lu has been identified. The measured decay Q value of 1920(20) keV is the highest measured for a ground-state proton decay, and it naturally leads to the shortest directly measured half-life of 450_{-100}^{+170} ns for a ground-state proton emitter. The decay rate is consistent with l_{p}=5 emission, suggesting a dominant πh_{11/2} component for the wave function of the proton-emitting state. Through nonadiabatic quasiparticle calculations it was concluded that ^{149}Lu is the most oblate deformed proton emitter observed to date.
Published: 2022
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47. Lifetime Measurements of Excited States in ^{172}Pt and the Variation of Quadrupole Transition Strength with Angular Momentum.

Author: Cederwall B, Doncel M, Aktas Ö, Ertoprak A, Liotta R, Qi C, Grahn T, Cullen DM, Hodge D, Giles M, Stolze S, Badran H, Braunroth T, Calverley T, Cox DM, Fang YD, Greenlees PT, Hilton J, Ideguchi E, Julin R, Juutinen S, Raju MK, Li H, Liu H, Matta S, Modamio V, Pakarinen J, Papadakis P, Partanen J, Petrache CM, Rahkila P, Ruotsalainen P, Sandzelius M, Sarén J, Scholey C, Sorri J, Subramaniam P, Taylor MJ, Uusitalo J, and Valiente-Dobón JJ
Abstract: Lifetimes of the first excited 2^{+} and 4^{+} states in the extremely neutron-deficient nuclide ^{172}Pt have been measured for the first time using the recoil-distance Doppler shift and recoil-decay tagging techniques. An unusually low value of the ratio B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+})=0.55(19) was found, similar to a handful of other such anomalous cases observed in the entire Segré chart. The observation adds to a cluster of a few extremely neutron-deficient nuclides of the heavy transition metals with neutron numbers N≈90-94 featuring the effect. No theoretical model calculations reported to date have been able to explain the anomalously low B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios observed in these cases. Such low values cannot, e.g., be explained within the framework of the geometrical collective model or by algebraic approaches within the interacting boson model framework. It is proposed that the group of B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios in the extremely neutron-deficient even-even W, Os, and Pt nuclei around neutron numbers N≈90-94 reveal a quantum phase transition from a seniority-conserving structure to a collective regime as a function of neutron number. Although a system governed by seniority symmetry is the only theoretical framework for which such an effect may naturally occur, the phenomenon is highly unexpected for these nuclei that are not situated near closed shells.
Published: 2018
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48. Blurring the boundaries: decays of multiparticle isomers at the proton drip line.

Author: Carroll RJ, Page RD, Joss DT, Uusitalo J, Darby IG, Andgren K, Cederwall B, Eeckhaudt S, Grahn T, Gray-Jones C, Greenlees PT, Hadinia B, Jones PM, Julin R, Juutinen S, Leino M, Leppänen AP, Nyman M, O'Donnell D, Pakarinen J, Rahkila P, Sandzelius M, Sarén J, Scholey C, Seweryniak D, and Simpson J
Abstract: A multiparticle spin-trap isomer has been discovered in the proton-unbound nucleus (73)(158)Ta85 . The isomer mainly decays by γ-ray emission with a half-life of 6.1(1) μs. Analysis of the γ-ray data shows that the isomer lies 2668 keV above the known 9+ state and has a spin 10ℏ higher and negative parity. This 19- isomer also has an 8644(11) keV, 1.4(2)% α-decay branch that populates the 9+ state in (154)Lu. No proton-decay branch from the isomer was identified, despite the isomer being unbound to proton emission by 3261(14) keV. This remarkable stability against proton emission is compared with theoretical predictions, and the implications for the extent of observable nuclides are considered.
Published: 2014
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49. Shell-structure and pairing interaction in superheavy nuclei: rotational properties of the z=104 nucleus (256)rf.

Author: Greenlees PT, Rubert J, Piot J, Gall BJ, Andersson LL, Asai M, Asfari Z, Cox DM, Dechery F, Dorvaux O, Grahn T, Hauschild K, Henning G, Herzan A, Herzberg RD, Heßberger FP, Jakobsson U, Jones P, Julin R, Juutinen S, Ketelhut S, Khoo TL, Leino M, Ljungvall J, Lopez-Martens A, Lozeva R, Nieminen P, Pakarinen J, Papadakis P, Parr E, Peura P, Rahkila P, Rinta-Antila S, Ruotsalainen P, Sandzelius M, Sarén J, Scholey C, Seweryniak D, Sorri J, Sulignano B, Theisen Ch, Uusitalo J, and Venhart M
Abstract: The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.
Published: 2012
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50. Comparison of gamma-ray coincidence and low-background gamma-ray singles spectrometry.

Author: Konki J, Greenlees PT, Jakobsson U, Jones P, Julin R, Juutinen S, Ketelhut S, Hauschild K, Kontro R, Leppänen AP, Lopez-Martens A, Mattila A, Nieminen P, Nyman M, Peräjärvi K, Peura P, Rahkila P, Ruotsalainen P, Sarén J, Scholey C, Sorri J, Toivonen H, Turunen J, and Uusitalo J
Subjects: Aerosols, Background Radiation, Germanium, Nuclear Physics legislation & jurisprudence, Air Pollution, Radioactive analysis, Gamma Rays, Spectrometry, Gamma methods
Abstract: Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma-gamma coincidence approach in elevated background conditions. However, measurement of gamma-gamma coincidences can clearly make the identification of different nuclides more reliable and efficient than using singles spectrometry alone. The optimum solution would be a low-background counting station capable of both singles and gamma-gamma coincidence spectrometry., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
Published: 2012
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