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The nuclei below lead but with more than 126 neutrons are crucial to an understanding of the astrophysical r process in producing nuclei heavier than A∼190. Despite their importance, the structure and properties of these nuclei remain experimentally untested as they are difficult to produce in nuclear reactions with stable beams. In a first exploration of the shell structure of this region, neutron excitations in ^{207}Hg have been probed using the neutron-adding (d,p) reaction in inverse kinematics. The radioactive beam of ^{206}Hg was delivered to the new ISOLDE Solenoidal Spectrometer at an energy above the Coulomb barrier. The spectroscopy of ^{207}Hg marks a first step in improving our understanding of the relevant structural properties of nuclei involved in a key part of the path of the r process. ispartof: Physical Review Letters vol:124 issue:6 ispartof: location:United States status: published

International audience; Excited states of the rubidium isotopes$_{37}^{87, 89, 91}$Rb have been studied at the INFN Legnaro National Laboratory. Measurements of the $\gamma$ -ray decay of fragments produced in binary grazing reactions resulting from the interaction of a beam of 530 MeV$^{96}$Zr ions with a$^{124}$Sn target have been complemented by studies of the $\gamma$ -ray decay of fission fragments produced in the interaction of a beam of 230 MeV$^{36}$S ions with a thick$^{176}$Yb target. The structure of the yrast states of$_{37}^{87, 89, 91}$Rb has been discussed within the context of spherical shell-model and cranked Nilsson-Strutinsky calculations.

In neutrinoless double-$\ensuremath{\beta}$ decay such as ${}^{136}$Xe to ${}^{136}$Ba, two neutrons become two protons, thus rearranging the occupancy of protons and neutrons in the ground states of the parent and daughter nuclei. From precision measurements of the cross sections of single-neutron adding and -removing reactions, the authors extract the change in ground-state neutron occupancies between ${}^{136}$Xe and ${}^{136}$Ba. Along with recent results on the proton occupancies, the new experimental neutron occupancies disagree with those used in existing theoretical calculations of the rate of this elusive $\ensuremath{\beta}$-decay mode, and provide a \hskip-0.22em \hskip-0.22embasis for improved estimates of the uncertainties for new calculations.

The change in the configuration of valence protons between the initial and final states in the neutrinoless double-$\beta$ decay of $^{130}$Te $\rightarrow$ $^{130}$Xe and of $^{136}$Xe $\rightarrow$ $^{136}$Ba has been determined by measuring the cross sections of the ($d$,$^3$He) reaction with 101-MeV deuterons. Together with our recent determination of the relevant neutron configurations involved in the process, a quantitative comparison with the latest shell-model and interacting-boson-model calculations reveals significant discrepancies. These are the same calculations used to determine the nuclear matrix elements governing the rate of neutrinoless double-$\beta$ decay in these systems.

Acta physica Polonica / B 47(3), 627 - 636(2016). doi:10.5506/APhysPolB.47.627, Published by Inst. of Physics, Jagellonian Univ., Cracow

© 2015 Elsevier B.V. It is planned to install the heavy-ion, low-energy ring TSR, currently at the Max-Planck-Institute for Nuclear Physics in Heidelberg, at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored, cooled secondary beams that is rich and varied, spanning from studies of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. In addition to experiments performed using beams recirculating within the ring, the cooled beams can be extracted and exploited by external spectrometers for high-precision measurements. The capabilities of the ring facility as well as some physics cases will be presented, together with a brief report on the status of the project. ispartof: Nuclear Instruments & Methods in Physics Research B vol:376 pages:270-274 ispartof: location:Grand Rapids: MI status: published

This paper describes the implementation and commissioning of a device based on a new concept for measurements of nuclear reactions in inverse kinematics. The HELIcal Orbit Spectrometer, HELIOS, was commissioned at Argonne National Laboratory by studying the 28Si(d,p)29Si reaction in inverse kinematics. This experiment served as a proof of principle for this previously untested concept, and was used to verify the response and performance characteristics of HELIOS.

The near-term radioactive beam capabilities of ATLAS include radioactive beams produced in flight in a gas cell, or starting in the fall of 2009, re-accelerated beams of 252 Cf fission fragments provided by the new CARIBU injector. The availability of such exotic beams will allow for detailed studies of the single-particle aspects of nuclear structure in neutron-rich nuclei reaching out to the astrophysical r-process path by employing light-ion reactions in inverse kinematics. The HELIOS spectrometer is based on a new concept that is especially well suited for such studies. This concept was recently demonstrated using the reactions D (28 Si , p )29 Si with a (stable) 168 MeV 28 Si beam. Since then D (12 B , p )13 B , D (17 O , p )18 O , and D (15 C , p )16 C have been studied successfully. The combination of neutron-rich beams from CARIBU and the HELIOS spectrometer opens a fertile research area of precision studies of the single particle strengths and collective excitations in exotic nuclei, and is likely to have applications in other reactions as well.

Zhu, S. Janssens, R. V. F. Fornal, B. Freeman, S. J. Honma, M. Broda, R. Carpenter, M. P. Deacon, A. N. Kay, B. P. Kondev, F. G. Krolas, W. Kozemczak, J. Larabee, A. Lauritsen, T. Liddick, S. N. Lister, C. J. Mantica, P. F. Otsuka, T. Pawlat, T. Robinson, A. Seweryniak, D. Smith, J. F. Steppenbeck, D. Tomlin, B. E. Wrzesinski, J. Wang, X.

The low-lying levels in 59,60Cr have been populated with 13,14C(48Ca, 2p) reactions using a beam energy of 130 MeV. Prompt electromagnetic radiation was detected using the Gammasphere array, in coincidence with recoiling ions measured with the Fragment Mass Analyzer. The residues were selected and identified on the basis of charge-to-mass ratio, energy-loss and time-of-flight measurements. Preliminary results for 60Cr, when compared to lighter even-even isotopes, indicate a softness in shape which increases with neutron number. The low-lying structure of 59Cr is clearly inconsistent with the results of a spherical shell-model calculation and requires the inclusion of the νg9/2 orbital. The sequence of states can be understood within the Nilsson model assuming a moderate oblate ground-state deformation. This is in contrast to lighter odd-Cr nuclei where there is evidence for prolate deformation after excitation of g9/2 neutrons.

A study of high spin states in the odd-neutron isotones 239 Pu and 237 U is reported. Striking differences were found in the high-spin properties of rotational bands built on the 1 /2 + [631] ground states in these two nuclei. These differences mirror those observed in the even–even Pu and U immediate neighbors and appear to be related to the strength of octupole correlations.

The fusion–evaporation reaction 10 B( 12 C, 2 n ) was used to make the first observation of in-beam γ decays from the astrophysically important nucleus 20 Na, lying adjacent to the proton drip-line. All states below the proton threshold in 20 Na were populated and identified in the experiment. These include new levels, previously unresolved levels, and states located with improved energy precision. The level structure of 20 Na, and its γ transitions, are compared to the mirror partner 20 F measured simultaneously in this experiment. In particular, a high degree of energy stability is found for all negative parity states. These results are discussed in the context of the nuclear shell model.

This paper reports on recent work using multi-nucleon transfer reactions to populate metastable states in neutron-rich, rare-earth and transitional nuclei with A∼180-200. The use of a position sensitive gas-filled detector, CHICO, allowed the directions of the binary fragments to be measured, thereby enabling event-by-event Doppler corrections to be made for the prompt, in-beam transitions depopulating the nuclei of interest. By using the temporal calibration provided by (i) the measurement of the binary reaction fragments and (ii) the natural pulsing of the cyclotron beam, transitions from metastable states with lifetimes in the nano-to-microsecond regime could be identified. The complementarity of this technique with the novel use of relativistic projectile fragmentation reactions is outlined, together with potential future avenues for this research, with a particular emphasis on the population of exotic isomeric states at high angular momentum and excitation energy values.

The GREAT spectrometer is designed to measure the decay properties of reaction products transported to the focal plane of a recoil separator. GREAT comprises a system of silicon, germanium and gas detectors optimised for detecting the arrival of the reaction products and correlating with any subsequent radioactive decay involving the emission of protons, α particles, β particles, γ rays, X-rays or conversion electrons. GREAT can either be employed as a sensitive stand-alone device for decay measurements at the focal plane, or used to provide a selective tag for prompt conversion electrons or γ rays measured with arrays of detectors deployed at the target position. A new concept of triggerless data acquisition (total data readout) has also been developed as part of the GREAT project, which circumvents the problems and limitations of common dead time in conventional data acquisition systems.

High-spin states in the N=Z nucleus 72Kr have been populated in the 40Ca(40Ca, 2α)72Kr fusion–evaporation reaction at a beam energy of 165 MeV and using a thin isotopically enriched 40Ca target. The experiment, performed at Argonne National Laboratory close to Chicago, USA, employed the Gammasphere array for γ-ray detection coupled to the Microball array for charged particle detection. The previously observed bands in 72Kr were extended to a higher excitation energy of ~24 MeV and higher angular momentum of 30. Using the Doppler-shift attenuation method, the lifetimes of high-spin states were measured for the first time in order to investigate deformation changes associated with the g9/2 proton and neutron alignments in this N=Z nucleus. An excellent agreement with theoretical calculations including only standard t=1 np pairing was observed.

Measurements of neutron-adding, neutron-removing, and proton-adding reactions were carried out for the four stable even Ni isotopes. Particular attention was paid to obtaining precise values of the cross sections at the peaks of the angular distributions. Tests with sum rules for the neutron data indicate that the results are self-consistent at the level of a few tenths of a nucleon. Data on proton-adding reactions were also obtained and analyzed with a slightly different method—while these data are also consistent, the ambiguities are larger. The occupancies of the neutron orbits derived from the data, the proton vacancies, and the energy centroids of the neutron, neutron-hole, and proton single-particle excitations are obtained. The data also provide some estimate about the closure of the 0 f 7 / 2 shell. The results are compared to shell-model calculations and may serve as a reference point for future exploration. ispartof: Physical Review C, Nuclear Physics vol:87 issue:3 pages:1-15 status: published

The low-lying level structure of the neutron-deficient isotope $^{200}\mathrm{Rn}$ has been studied using the $^{176}\mathrm{Hf}$${(}^{28}$Si,4n) reaction at a beam energy of 142 MeV. Evaporation residues were selected using an in-flight recoil mass separator, the Argonne Fragment Mass Analyzer, and implanted in a double-sided silicon strip detector. Prompt \ensuremath{\gamma} rays in $^{200}\mathrm{Rn}$ were observed at the target position using the AYEBALL array of 19 Compton-suppressed germanium detectors, and were identified by the subsequent radioactive decay of associated recoiling ions in the strip detector. Isotopic assignments of the nuclei produced were made on the basis of the mass-to-charge ratio of the recoiling ion and the energy and half-life of its \ensuremath{\alpha} decay. Previous results concerning transitions in $^{202}\mathrm{Rn}$ were confirmed. The level scheme deduced for $^{200}\mathrm{Rn}$, compared with those of heavier radon isotopes, is not consistent with the onset of deformation predicted by theoretical calculations. The estimated production cross section for $^{200}\mathrm{Rn}$ in this reaction was 5 \ensuremath{\mu}b. \textcopyright{} 1996 The American Physical Society.

K-isomers are states in deformed nuclei whose {gamma}-decay is hindered by selection rules involving K, the projection of the angular momentum along the axis of symmetry of the nucleus. Previous work with the Argonne Notre Dame BGO Array delineated the existence of two K-isomers in {sup 176}W, one of which had a very unusual pattern of decay. A short description of this work was published as a letter, and a more complete account is being readied for submission. These results provided evidence that quantum-mechanical fluctuations in the nuclear shape may be responsible for some of the observed K-violating transitions. In addition, hints were present in the data of the existence of another K-isomer with an even higher in. An experiment was performed in September 1994 to observe this isomer, using the reaction {sup 50}Ti({sup 130}Te,4n), and a technique in which recoiling {sup 176}W nuclei were created 17-cm upstream of the center of the array and caught on a Pb catcher foil at the center. Intense ({approximately} 3 pnA) beams of {sup 130}Te were supplied by the ECR source using a new sputtering technique. The recoil-shadow geometry was highly successful at removing the background from non-isomeric decays, allowing the weakly populatedmore » K-isomers to be detected cleanly. In addition, the availability of pulsed beams from ATLAS and the timing data from the BGO array provided a second technique for isolating the decays of interest, by selecting events in which a given number of BGO detectors fired between beam pulses. This method was used in the previous experiment, and was also applied in this experiment as a second level of selection. As a result, gamma-ray transitions were detected in the present experiment with intensities as small as {approximately} 0.02 % of the {sup 176}W reaction channel. The existence of the new isomer was confirmed, and a partial level-scheme was constructed.« less

We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report. ispartof: European Physical Journal. Special Topics vol:207 issue:1 pages:1-117 status: published

The quantitative consistency of nucleon transfer reactions as a probe of the occupancy of valence orbits in nuclei is tested. Neutron-adding, neutron-removal, and proton-adding transfer reactions were measured on the four stable even Ni isotopes, with particular attention to the cross section determinations. The data were analyzed consistently in terms of the distorted wave Born approximation to yield spectroscopic factors. Valence-orbit occupancies were extracted, utilizing the Macfarlane-French sum rules. The deduced occupancies are consistent with the changing number of valence neutrons, as are the vacancies for protons, both at the level of

The single-neutron properties of the $N=83$ nucleus ${}^{137}$Xe have been studied using the ${}^{136}$Xe($d$,$p$) reaction in inverse kinematics at a beam energy of 10 MeV/u. The helical-orbit spectrometer, HELIOS, at Argonne National Laboratory was used to analyze the outgoing protons, achieving an excitation-energy resolution of \ensuremath{\sim}100 keV. Extraction of absolute cross sections, angular distributions, and spectroscopic factors has led to a more complete understanding of the single-neutron strength in ${}^{137}$Xe. In particular, the centroids of the $\ensuremath{\nu}{h}_{9/2}$ and $\ensuremath{\nu}{i}_{13/2}$ strengths appear to evolve through the $N=83$ isotones in a manner consistent with the action of the tensor force.

Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.

A first experiment is reported that makes use of a new kind of spectrometer uniquely suited to the study of reactions with radioactive beams in inverse kinematics, the helical orbit spectrometer, HELIOS. The properties of some low-lying states in the neutron-rich $N=8$ nucleus $^{13}\mathrm{B}$ were studied with good resolution. From the measured angular distributions of the $(d,\text{\hskip-0.22em}p)$ reaction and the relative spectroscopic factors, spin and configuration assignments of the first- and third-excited states of this nucleus can be constrained.

We report on one- and two-neutron transfer reactions to study the single-particle properties of nuclei at the border of the "island of inversion". The (d,p)- and (t,p)-reactions in inverse kinematics on the neutron-rich isotope 30Mg, delivered as radioactive beam by the REX-ISOLDE facility, have been investigated. The outgoing protons have been detected and identified by a newly built array of Si detectors. The gamma-decay of excited states has been detected in coincidence by the MINIBALL array. First results for 31Mg and from the search for the second, spherical, 0+ state in 32Mg are presented. ispartof: pages:363-368 ispartof: AIP Conference Proceedings vol:1165 issue:1 pages:363-368 ispartof: Nuclear structure and dynamics \09 location:Dubrovnik, Croatia date:4 May - 9 May 2009 status: published

Two experimental setups have been used to study excited states of neutron‐rich nuclei in the A∼100 region. Extended level schemes and lifetime measurements were obtained using deep‐inelastic and fusion‐fission reactions with the CLARA‐PRISMA spectrometer and the Ge‐array GASP respectively. Experimental information from GASP has been used to complement the CLARA‐PRISMA experiment. Time spectra have been used to measure the lifetimes of isomeric states. Preliminary results are presented for 89Rb.

Valiente-Dobon, J. J. Lenzi, S. M. Freeman, S. J. Lunardi, S. Smith, J. F. Gottardo, A. Della Vedova, F. Farnea, E. Gadea, A. Napoli, D. R. Axiotis, M. Aydin, S. Bazzacco, D. Bizzeti, P. G. Bizzeti-Sona, A. M. Benzoni, G. Bucurescu, D. Corradi, L. Deacon, A. N. de Angelis, G. Fioretto, E. Guiot, B. Ionescu-Bujor, M. Iordachescu, A. Leoni, S. Marginean, N. Marginean, R. Mason, P. Menegazzo, R. Mengoni, D. Million, B. Montagnoli, G. Orlandi, R. Recchia, F. Sahin, E. Scarlassara, F. Singh, R. P. Stefanini, A. M. Steppenbeck, D. Szilner, S. Ur, C. A. Varley, B. J. Wieland, O.

Excited states of the extremely neutron-deficient radon isotopes with N = 111, 113, 115 have been studied for the first time in a series of in-beam experiments performed at the Accelerator Laborato ...

The possibility of observing neutrinoless double {beta} decay offers the opportunity of determining the effective neutrino mass if the nuclear matrix element were known. Theoretical calculations are uncertain, and measurements of the occupations of valence orbits by nucleons active in the decay can be important. The occupation of valence neutron orbits in the ground states of {sup 76}Ge (a candidate for such decay) and {sup 76}Se (the daughter nucleus) were determined by precisely measuring cross sections for both neutron-adding and removing transfer reactions. Our results indicate that the Fermi surface is much more diffuse than in theoretical calculations. We find that the populations of at least three orbits change significantly between these two ground states while in the calculations, the changes are confined primarily to one orbit.

The structure of the neutron-rich isotopes $^{59,60}\mathrm{Fe}$ has been studied with the Gammasphere detector array using fusion-evaporation reactions. Level schemes for these nuclei are presented which have been extended to spins of $~20\ensuremath{\hbar}$. Both isotopes exhibit regular, near-yrast \ensuremath{\gamma}-decay sequences which are generated by the intrusion of the ${g}_{9/2}$ orbital into the $\mathit{fp}$ shell-model space. Lower-spin, natural-parity levels are discussed within the context of shell-model calculations using the GXPF1A interaction in the full $\mathit{fp}$ model space. Experimental features of the high-spin bands are compared with total Routhian surface calculations.

Lunardi, S. Lenzi, S. M. Della Vedova, F. Farnea, E. Gadea, A. Marginean, N. Bazzacco, D. Beghini, S. Bizzeti, P. G. Bizzeti-Sona, A. M. Bucurescu, D. Corradi, L. Deacon, A. N. de Angelis, G. Fioretto, E. Freeman, S. J. Ionescu-Bujor, M. Iordachescu, A. Mason, P. Mengoni, D. Montagnoli, G. Napoli, D. R. Nowacki, F. Orlandi, R. Pollarolo, G. Recchia, F. Scarlassara, F. Smith, J. F. Stefanini, A. M. Szilner, S. Ur, C. A. Valiente-Dobon, J. J. Varley, B. J.

High-spin states in the N=Z nucleus {sup 72}Kr have been populated in the {sup 40}Ca({sup 40}Ca, 2{alpha}){sup 72}Kr fusion-evaporation reaction at a beam energy of 165 MeV using the Gammasphere array for {gamma}-ray detection coupled to the Microball array for charged particle detection. The previously observed bands in {sup 72}Kr were extended to an excitation energy of {approx}24 MeV and angular momentum of 30({Dirac_h}/2{pi}). Using the Doppler shift attenuation method the lifetimes of high-spin states were measured for the first time. Excellent agreement between the results of calculations within the isovector mean field theory and experiment is observed both for rotational and deformation properties. No enhancement of quadrupole deformation expected in the presence of isoscalar t=0 np pairing is observed. Current data do not show any evidence for the existence of the isoscalar np pairing.

High-spin states in $^{76}\mathrm{Sr}$ have been studied using Gammasphere plus Microball detector arrays. The known yrast band has been extended beyond the first band crossing, which involves the simultaneous alignment of pairs of ${\mathrm{g}}_{\frac{9}{2}}$ protons and neutrons, to a tentative spin of $24\ensuremath{\hbar}$. The data are compared with the results of cranked relativistic mean-field (CRMF) and cranked relativistic Hartree-Bogoliubov (CRHB) calculations. The properties of the band, including the ${\mathrm{g}}_{\frac{9}{2}}$ proton/neutron band crossing frequency and moments of inertia, are found to be well reproduced by the CRHB calculations. Furthermore, the unpaired CRMF calculations show quite good agreement with the data beyond the band crossing region, indicating that pairing is weak at these frequencies. The high spin results suggest that there is little evidence for an isoscalar $(t=0)$ $\mathit{np}$ pair field. Moreover, a systematic study of the band crossings in even-even $N=Z$ nuclei for the first time reveals that there is no evidence to support the existence of the Coulomb antipairing effect caused by the Coulomb exchange term.

The structure of the $^{56,58,60}\mathrm{Cr}$ nuclei was investigated at Gammasphere using both deep inelastic and fusion-evaporation reactions. As a result of this work, expanded level schemes are now available for these three neutron-rich, even-even isotopes. Experimental signatures were found for both single-particle and collective excitations whose relative importance varies with neutron number. Together with recent structural information on the odd-$A$ $^{55,57,59}\mathrm{Cr}$ neighbors, the present data highlight the changing role of the ${g}_{9/2}$ orbital with neutron number. Comparisons with shell-model calculations using the recently developed GXPF1A interaction and with total Routhian surface calculations are presented.

The one-neutron knockout reaction $^{9}\mathrm{Be}$($^{57}\mathrm{Cr}$,$^{56}\mathrm{Cr}$+\ensuremath{\gamma})X has been measured in inverse kinematics with an intermediate-energy beam. Cross sections to individual states in $^{56}\mathrm{Cr}$ were partially untangled through the detection of the characteristic \ensuremath{\gamma}-ray transitions in coincidence with the reaction residues. The experimental inclusive longitudinal momentum distribution and the yields to individual states are compared to calculations that combine spectroscopic factors from the full $\mathit{fp}$ shell model and nucleon-removal cross sections computed in a few-body eikonal approach.

The heavy-ion radiative capture reaction, $^{12}\mathrm{C}(^{12}\mathrm{C},\ensuremath{\gamma})$, has been investigated at beam energies around 16 MeV. Two different experiments were performed. Capture cross sections were obtained by measuring fused $^{24}\mathrm{Mg}$ residues and were found to significantly exceed values reported earlier. Subsequently, the decay pathways associated with radiative capture were delineated using the Gammasphere array. A substantial fraction of the decay was found to proceed through a few high-lying doorway states near 10 MeV in excitation.

CLARA is an array of 25 Clover (EUROBALL type) Ge detectors, placed at the target position of the large acceptance magnetic spectrometer PRISMA. Due to the granularity of the CLARA Ge array (100 crystals), the photopeak efficiency ($\approx$3%) and the PRISMA large acceptance ($\approx$80 msr, and 20% $\Delta$p/p), the setup is an excellent tool to investigate the structure of neutron-rich nuclei, populated in multinucleon transfer reactions and deep inelastic collisions with stable beams. Since March 2004 the setup is fully operational, and since then several experiments have been performed, with beams delivered by the LNL XTU-Tandem and the ALPI linac. In this contribution the preliminary outcome of the first experiments is shown.

Gamma decays depopulating excited states in the odd‐odd N=Z − 2 nucleus 48Mn have been observed for the first time. The yrast band has been built up from the 4+ ground state to 13+, just shy of the expected band termination at 15+. When compared with its mirror, 48V, the Coulomb energy differences are unlike any other previously measured which, until now, have been dominated by a sudden rotational alignment. Such an alignment is expected to be blocked in these odd‐odd nuclei and calculations not only confirm this, but also infer that any Coulomb difference is mostly due to monopole effects.

The heavy‐ion radiative capture reaction, 12C(12C,γ), has been investigated at beam energies around 16 MeV. Three different experiments were performed. Capture cross‐sections were obtained by measuring fused 24Mg residues using the FMA at ANL. These were found to significantly exceed values reported earlier. Subsequently, the decay pathways associated with radiative capture were studied in two separate measurements: one with the high‐resolution Gammasphere array and a second with a high efficiency BGO array, where gamma rays were recorded in coincidence with 24Mg residues detected at the focal plane of the DRAGON recoil separator at TRIUMF. Both measurements indicate that a substantial fraction of the decay is mediated through high‐lying doorway states, possibly associated with the long‐predicted shape‐isomeric band in 24Mg.

International audience; Proton decay has been transformed in recent years from an exotic phenomenon into a powerful spectroscopic tool. The frontiers of experimental and theoretical proton-decay studies will be reviewed. Different aspects of proton decay will be illustrated with recent results on the deformed proton emitter $^{135}$Tb, the odd–odd deformed proton emitter $^{130}$Eu, the complex fine structure in the odd–odd $^{146}$Tm nucleus and on excited states in the transitional proton emitter $^{145}$Tm.

International audience; Gamma-rays from the odd-odd transitional proton-emitting nucleus 146Tm have been observed using the recoil-decay tagging technique. A rotational band similar to the h_11/2 decoupled band in 147Tm has been observed. The particle decay of 146Tm has been measured with improved statistics. A new decay scheme for 146Tm is discussed with reference to prompt and delayed gamma-rays detected in coincidence with particle decays.

The possible occurrence of sub‐shell gaps at N = 32 and N = 34 in neutron‐rich titanium isotopes is discussed in light of new experimental results from (i) deep‐inelastic reactions measured with Gammasphere at the ATLAS facility at Argonne National Laboratory and from (ii) intermediate‐energy Coulomb excitation performed at the National Superconducting Cyclotron Laboratory at Michigan State University.

The present work reports on the 76195Os isotope, which is the most neutron‐rich osmium isotope for which transitions have been measured. It has been populated following a multi‐nucleon transfer reaction between a thin 78198Pt target and an 850‐MeV 54136Xe beam. Evidence from γ‐ray coincidences has been found for an Iπ = (272−) isomeric state with a measured half‐life of 26 ± 9ns.