Search

International audience; The pre-formation of α-clusters in α-conjugate nuclei or their dynamical condensation during nuclear reactions was largely debated, among the methods to probe a possible cluster structure in nuclei, it has been suggested to study pre-equilibrium emitted particles and clusters following their emission during the dynamical part of the reaction, before a full thermalization takes place.

Transition probabilities of intermediate-spin yrast and non-yrast excitations in 80, 82Se were investigated in a recoil distance Doppler-shift (RDDS) experiment performed at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. The Cologne Plunger device for deep inelastic scattering was used for the RDDS technique and was combined with the AGATA Demonstrator array for the γ-ray detection and coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 80Se, the level lifetimes of the yrast (6+1) and (8+1) states and of a non-yrast band feeding the yrast 4+1 state are determined. A spin and parity assignment of the head of this sideband is discussed based on the experimental results and supported by large-scale shell-model calculations. In 82Se, the level lifetimes of the yrast 6+1 state and the yrare 4+2 state and lifetime limits of the yrast (10+1) state and of the 5−1 state are determined. Although the experimental results contain large uncertainties, they are interpreted with care in terms of large-scale shell-model calculations using the effective interactions JUN45 and jj44b. The excited states' wave functions are investigated and discussed with respect to the role of the neutron g9/2 orbital.

Background A 7 month child with an unremarkable previous medical history presented with a history of 18 days of severe secretory diarrhoea. Clinical and histological features were consistent with autoimmune enteropathy. The patient could not tolerate foods, and was started on total parental nutrition (TPN) and i.v. Methylprednisolone, without substantial clinical improvement. Confirmed resistance to traditional therapy and consulted hospital pharmacists. The use of tacrolimus was identified as the best option. Purpose The aim of this work is to report several aspects of the hospital pharmacy’s involvement in the management of a difficult case, including off-label approval, compounding, alternative therapies, nutritional support and costs. Material and methods Being not registered for use, the corporate formal procedure for off-label drugs was submitted to ‘Corporate Commission off-label’ involving a designated pharmacist, pharmacologist and clinic. Parents signed formal ‘informed consent’ and medical records were verified. Tacrolimus suspension 0.5 mg/ml to 40 ml was prepared according to the scientific literature and compounding formulas, using a basic vehicle for the compounding of oral liquid dosage forms (stability 56 days, storage at 24°C–26°C). An appropriate personalised TPN was formulated. Results Drugs: i.v. methylprednisolone was used at 1.5 mg/kg/day for 1 month, with dose tapering in 3 months. Tacrolimus was used as a unique therapy for 5 months (mean dose: 0.15 mg/kg/day), and associated with azathioprine at 2.5 mg/kg/day for 2 months. Twenty-two bottles of tacrolimus were prepared for €730 overall. Tacrolimus and azathioprine were stopped during a fungal infection, after which only azathioprine was restarted. No adverse reactions were reported. Nutrition: TPN for 3 months with soy-based lipid mixture (50% soybean oil:50% MCT 3 g/kg/day) and for 11 months with fish-oil lipid mixture (30% soybean oil:30% MCT:25% olive oil:15% fish oil 2.5 g/kg/day). Optimal tolerance to PN and appropriate weight gain. PN was progressively reduced and an elemental liquid oral formula introduced. Overall, after 16 months, clinical and histological condition substantially improved and the patient currently tolerates enteral nutrition with elemental formula plus azathioprine. Conclusion Rare paediatric diseases are always a challenge for the hospital medical staff. In this case the medical plan is to slowly reintroduce hypoantigenic foods and stop azathioprine. Given the disease rarity, we hope to increase available data and help the management of similar cases. References and/or Acknowledgements Thanks to Corporate Commission off-label No conflict of interest

Background In April 2016 the Central IntraVenous Additive Service (CIVAS) began to compound non-toxic injectable therapies with a robotic system.1 The production started with antiemetic therapies, followed by antibiotic therapies ready to infuse, as cefazoline 1 g in syringes and piperacillin-tazobactam 4.5 g in bags. Purpose The purpose of this study is to present the new drugs involved that led to production increasing and to describe how CIVAS guarantees the non-hazardous preparations’ supply to hospital departments. Material and methods An analysis concerning the actual hospital antibiotic treatment needs has been carried out through the electronic medical record (EMR). Drugs in ready-to-use injectable form were immediately excluded as well as those with a daily consumption under 20 units. Among the remaining amount of medications, only those with a sufficient physical and chemical stability,2 that allow batch production and at least 7 days of storage, were considered. For every new molecule, a testing production with five batchs of 10 preparations each were compounded through a robotic system, in order to evaluate the dosage accuracy. Results The new validated drugs included in the automated production result were: oxacillin 1 g, cefotaxime 2 g, azithromycin 500 mg, vancomycin 500 mg and ceftriaxone 1 g, all in 100 ml NaCl bags. The average dosage accuracy ranges from 93.43% of azithromycin to 99.64% of cefotaxime, always compliant with the 10% error limit set by the Official Pharmacopoeia. The annual workload, including piperacillin-tazobactam 4.5 g and cefazoline 1 g already compounded inside the automated system, is estimated as 80 000 bags. Conclusion Within 2017, the robotic system will cover the dispensing of antibiotic treatments of 50% of hospital departments, reaching 100% by the end of 2018. References and/or Acknowledgements 1. Bufarini C, et al. Centralised non-hazardous intravenous compounding: from theory to clinical practice. Eur J Hosp Pharm2017;24(1):A1–A288 PP-041. 2. ‘Stabilis 4.0’. www.stabilis.org No conflict of interest

Background Due to the toxicity of drugs involved, chemotherapy represents an high-risk treatment, both for operators and patients. To improve the safety of the oncologic therapy admixture process, in 2007 the clinical pharmacy introduced an automated system for the compounding of toxic drugs. The system is integrated with the hospital electronic medical record (EMR) and assures high levels of quality controls and a total traceability of the entire process. Purpose Since the safety and high-quality standards of the re-engineered process have been assessed,1 the purpose of this study is to evaluate also its economic sustainability and the related production efficiency. Material and methods To assess the economic sustainability of the automation, a cost analysis has been performed. Fixed costs (equipment investment, maintenance, human resources, personal protective equipments) and variable costs (compounding disposables and administrative management of the process) have been calculated both for the manual and automated compounding model, and the consequent differential saving has been estimated. In addition, we have evaluated the possibility of also centralising the production by taking into consideration the need of other hospitals and healthcare facilities in the region. Results The re-engineering of the onco-haematology process led to an annual saving of €85.715, with a marginal saving of €5.49 per preparation, a break-even point of 4.1 therapies and a return on investment in 3.3 years (against 8 years’ life-time of the robotic system). Furthermore, the total automated production capacity is estimated in 24.865 preparations per year where the 79.3% is sufficient to cover the annual hospital (hub) needs. Therefore, the residual capacity, corresponding to 5.145 annual preparations, can be allocated to satisfy the requests coming from other compounding facilities (spokes). Conclusion Besides the minimisation of the risks related to the automated production and the benefits coming from the re-engineering of the process,1 the economic sustainability of the investment and the production centralisation feasibility have been demonstrated. Reference and/or Acknowledgements 1. Bufarini C, et al. Safe and integrated onco-haematology workflow, 19th EAHP Congress 2014. No conflict of interest

A Coulomb-excitation experiment to study electromagnetic properties of Ca42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in Ca42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca42, including the diagonal E2 matrix elements of 21+ and 22+ states, were determined using the least-squares code gosia. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 01,2+ and 21,2+ states, as well as triaxiality for 01,2+ states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca42.

An in-beam test of two pixel-type silicon detectors of the TRACE detector project has been performed at Laboratori Nazionali di Legnaro (Italy). The aim was to investigate the lowest kinetic energy values at which isotopic identification of heavy-ion reactions products with mass $ A\sim 10$ is possible, by using a single-layer silicon detector. Two separate read-out chains, analog and digital, were used, and the Pulse Shape Analysis technique was employed to obtain the particle identification matrices for the digitally processed data. The results confirmed the high capability of the Pulse Shape Analysis method which can be used for light ion identification, with performances similar to the analog approach. Separation in both charge and mass was obtained for Li and Be isotopes, however, the presence of a significant background from alpha particles severely limited the data analysis in the lower energy region. Due to this effect, the identification of the light products (7, 6Li isotopes) could be possible down to $ \sim 24.5$ MeV only, while the 9, 7Be isotopes were separable down to $ \sim 29$ MeV. This gives the value of $ < 4$ MeV/nucleon as the lowest kinetic energy for light products identification by using the pixel-type detectors of the TRACE project, in the present experimental conditions.

Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2 238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example. Keywords: Nuclear reactions, Deep-inelastic collisions, Exotic nuclei

Advances in nuclear structures studies of neutron-rich systems are presented, focusing on experimental activities based on γ and particle spectroscopy—ideal probes of the multifaceted nature of the atomic nucleus. Emphasis is given to recent highlights obtained in world’s leading laboratories, in Europe and Japan, by large international collaborations in which the Nuclear Physics group of Milano University has played a key role. In particular, experiments are described taking advantage of both stable and radioactive ion beams, as well as intense neutron beams. They require the use of the most advanced detection setups, such as the European array AGATA, based on γ-ray tracking techniques, and also arrays of large size scintillators. Measurements of cross sections of thermonuclear fusion reactions at astrophysically relevant energies, performed by the LUNA collaboration, are also briefly discussed. Finally, research and developments of detectors based on novel scintillators materials are presented, being a significant part of the activity carried out at the Milano Physics Department.

Background: While the $N=50$ shell-gap evolution towards $^{78}\mathrm{Ni}$ is presently in the focus of nuclear structure research, experimental information on the neutron effective single-particle energy sequence above the $^{78}\mathrm{Ni}$ core remain scarce. Direct nucleon-exchange reactions are indeed difficult with presently available post-accelerated radioactive-ion beams (especially for high orbital-momentum orbitals) in this exotic region.Purpose: In this study we probe the evolution of the $\ensuremath{\nu}1{g}_{7/2}$ effective single-particle energy which is a key to understanding the possible evolution of the spin-orbit splitting due to the proton-neutron interaction in the $^{78}\mathrm{Ni}$ region. To achieve this goal, a method based on lifetime measurements is used for the first time. The obtained lifetimes of the $7/{2}_{1}^{+}$ states in $^{87}\mathrm{Kr}$ and $^{85}\mathrm{Se}$ are used to investigate the $\ensuremath{\nu}1{g}_{7/2}$ evolution.Method: Yrast and near-yrast states in the light $N=51$ isotones $^{85}\mathrm{Se}$ and $^{87}\mathrm{Kr}$ were populated via multinucleon transfer reactions, using a $^{82}\mathrm{Se}$ beam and a $^{238}\mathrm{U}$ target at the LNL tandem-ALPI facility. The prompt $\ensuremath{\gamma}$ rays were detected by the AGATA Demonstrator and particle identification was performed using the PRISMA spectrometer. Lifetime measurements were performed by using the Cologne plunger device for deep inelastic reactions and the Recoil Distance Doppler Shift technique.Results: We obtain ${\ensuremath{\tau}}_{(7/{2}_{1}^{+})}=0.{4}_{\ensuremath{-}0.4}^{+1.6}$ ps for $^{87}\mathrm{Kr}$. In the case of $^{85}\mathrm{Se}$ an upper limit of 3(2) ps is obtained for the ${\ensuremath{\tau}}_{7/{2}_{1}^{+}}$ value.Conclusion: For $^{87}\mathrm{Kr}$, the measured $(7/{2}_{1}^{+})$ lifetime is consistent with a core-coupled ${2}^{+}\ensuremath{\bigotimes}\ensuremath{\nu}2{d}_{5/2}$ configuration for this state. This result is consistent with that obtained by direct reaction, which validates our method. For $^{85}\mathrm{Se}$, the measured $7/{2}_{1}^{+}$ lifetime limit indicates a very small contribution of the $\ensuremath{\nu}1{g}_{7/2}$ configuration to the wave function of this state.

L. Pellegri et al. ; 5 pags. ; 6 figs. ; open access article under the CC BY license. Funded by SCOAP3, © 2014 The Authors. The γ decay from the high-lying states of 124Sn was measured using the inelastic scattering of 17O at 340 MeV. The emitted γ rays were detected with high resolution with the AGATA demonstrator array and the scattered ions were detected in two segmented δE-E silicon telescopes. The angular distribution was measured both for the γ rays and the scattered 17O ions. An accumulation of E1 strength below the particle threshold was found and compared with previous data obtained with (γ, γ') and (α, α'γ) reactions. The present results of elastic scattering, and excitation of E2 and E1 states were analysed using the DWBA approach. From this comprehensive description the isoscalar component of the 1- excited states was extracted. The obtained values are based on the comparison of the data with DWBA calculations including a form factor deduced using a microscopic transition density., Grant No. 2011/03/B/ST2/01894; (iii) the National Superconducting Cyclotron Laboratory at MSU; (iv) the US NSF Grant PHY-1204486; and the German BMBF under Grant 06KY9136.

International audience; The low-spin structure of the 206Tl nucleus has been investigated with the FIPPS prompt γ-ray spectrometer of ILL making use of the 205Tl(n,γ)206Tl reaction and the γ-coincidence technique. A large number of excitations up to the neutron binding energy (at 6.5 MeV) in 206Tl were observed. Preliminary results of the data analysis provided the information on the decay scheme of the capture state in 206Tl and on the multipolarities of a number of γ rays. The comparison of the experimental data with shell-model calculations will help describing the proton–hole and neutron–hole couplings near the doubly magic core 208Pb, benchmarking single-particle levels and two-body matrix elements of the residual interaction in this important region of the nuclear chart.

Author(s): Vogt, A; Siciliano, M; Birkenbach, B; Reiter, P; Hadynska-Klȩk, K; Wheldon, C; Valiente-Dobon, JJ; Teruya, E; Yoshinaga, N; Arnswald, K; Bazzacco, D; Blazhev, A; Bracco, A; Bruyneel, B; Chakrawarthy, RS; Chapman, R; Cline, D; Corradi, L; Crespi, FCL; Cromaz, M; De Angelis, G; Eberth, J; Fallon, P; Farnea, E; Fioretto, E; Fransen, C; Freeman, SJ; Fu, B; Gadea, A; Gelletly, W; Giaz, A; Gorgen, A; Gottardo, A; Hayes, AB; Hess, H; Hetzenegger, R; Hirsch, R; Hua, H; John, PR; Jolie, J; Jungclaus, A; Karayonchev, V; Kaya, L; Korten, W; Lee, IY; Leoni, S; Liang, X; Lunardi, S; MacChiavelli, AO; Menegazzo, R; Mengoni, D; Michelagnoli, C; Mijatovic, T; Montagnoli, G; Montanari, D; Muller-Gatermann, C; Napoli, D; Pearson, CJ; Podolyak, Z; Pollarolo, G; Pullia, A; Queiser, M; Recchia, F; Regan, PH; Regis, JM; Saed-Samii, N; Sahin, E; Scarlassara, F; Seidlitz, M; Siebeck, B; Sletten, G; Smith, JF; Soderstrom, PA; Stefanini, AM; Stezowski, O; Szilner, S; Szpak, B; Teng, R; Ur, C; Warner, DD; Wolf, K; Wu, CY; Zell, KO | Abstract: The transitional nuclei Xe132 and Xe133 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in Xe136+Pb208 MNT reactions employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (ii) in the Xe136+Pt198 MNT reaction employing the GAMMASPHERE spectrometer in combination with the gas-detector array CHICO, and (iii) as an evaporation residue after a Te130(α,xn)Xe134-xn fusion-evaporation reaction employing the HORUS γ-ray array at the University of Cologne. The high-spin level schemes are considerably extended above the Jπ=(7-) and (10+) isomers in Xe132 and above the 11/2- isomer in Xe133. The results are compared to the high-spin systematics of the Z=54 as well as the N=78 and N=79 chains. Furthermore, evidence is found for a long-lived (T1/2â‰1μs) isomer in Xe133 which closes a gap along the N=79 isotones. Shell-model calculations employing the SN100PN and PQM130 effective interactions reproduce the experimental findings and provide guidance to the interpretation of the observed high-spin features.

The neutron-rich nucleus \nucleus{200}{Pt} is investigated via in-beam \gamma-ray spectroscopy in order to study the shape evolution in the neutron-rich platinum isotopes towards the N = 126 shell closure. The two-neutron transfer reaction \nucleus{198}{Pt}(\nucleus{82}{Se}, \nucleus{80}{Se})\nucleus{200}{Pt} is used to populate excited states of \nucleus{200}{Pt}. The Advanced Gamma Ray Tracking Array (AGATA) demonstrator coupled with the PRISMA spectrometer detects \gamma rays coincident with the \nucleus{80}{Se} recoils, the binary partner of \nucleus{200}{Pt}. The binary partner method is applied to extract the \gamma-ray transitions and build the level scheme of \nucleus{200}{Pt}. The level at 1884\,keV reported by Yates et. al [Phys. Rev. C 37, 1889] was confirmed to be at 1882.1\,keV and assigned as the (6^+_1) state. An additional \gamma ray was found and it presumably de-excites the (8^+_1) state. The results are compared with state-of-the-art beyond mean-field calculations, performed for the even-even \nucleus{190-204}{Pt} isotopes, revealing that \nucleus{200}{Pt} marks the transition from the \gamma-unstable behaviour of lighter Pt nuclei towards a more spherical one when approaching the N=126 shell closure.

The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This setup exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam γ-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy γ rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA l π array are presented. Title in WoS: Conceptual design of the AGATA 1 pi array at GANIL

A search for shape isomers in the ^{66}Ni nucleus was performed, following old suggestions of various mean-field models and recent ones, based on state-of-the-art Monte Carlo shell model (MCSM), all considering ^{66}Ni as the lightest nuclear system with shape isomerism. By employing the two-neutron transfer reaction induced by an ^{18}O beam on a ^{64}Ni target, at the sub-Coulomb barrier energy of 39 MeV, all three lowest-excited 0^{+} states in ^{66}Ni were populated and their γ decay was observed by γ-coincidence technique. The 0^{+} states lifetimes were assessed with the plunger method, yielding for the 0_{2}^{+}, 0_{3}^{+}, and 0_{4}^{+} decay to the 2_{1}^{+} state the B(E2) values of 4.3, 0.1, and 0.2 Weisskopf units (W.u.), respectively. MCSM calculations correctly predict the existence of all three excited 0^{+} states, pointing to the oblate, spherical, and prolate nature of the consecutive excitations. In addition, they account for the hindrance of the E2 decay from the prolate 0_{4}^{+} to the spherical 2_{1}^{+} state, although overestimating its value. This result makes ^{66}Ni a unique nuclear system, apart from ^{236,238}U, in which a retarded γ transition from a 0^{+} deformed state to a spherical configuration is observed, resembling a shape-isomerlike behavior.

We evaluated the floristic and ecological attributes of a seasonal semideciduous forest remnant (SSF) (500-1,050 m) located in a key area for biodiversity conservation. The importance of the fragment to the ecosystem conservation was revealed by its species richness (253), diversity (Shannon index = 4.6; Simpson's complementary index = 0.98) and evenness (Pielou index = 0.83), which are considered high values for a SSF. Zoochory occurred in 77% of the species, indicating the existence of important biotic interactions that ensure the occurrence of gene flow. We recorded 14 endangered species, among which two are rare (Trigynaea oblongifolia and Trattinnickia ferruginea) and two are indicators of mature forests (Trattinnickia ferruginea and Virola bicuhyba). We confirmed the importance of key areas for biodiversity conservation and of the Atlantic SSF located at the 0-1,000 m altitudinal range. These areas deserve attention from conservationists due to the high species richness and high number of endemic and endangered species. RESUMO Avaliamos atributos florísticos e ecológicos de um remanescente de Floresta Estacional Semidecidual (FESD) (500-1.050 m) localizado em uma área-chave para conservação da biodiversidade. Evidenciamos a importância da conservação do fragmento devido à riqueza de espécies arbóreas (253), diversidade (Índice de Shannon = 4,6; Índice complementar de Simpson = 0,98) e equabilidade (Índice de Pielou = 0,83), que são considerados valores altos para uma FESD. A síndrome zoocórica representou 77% das espécies, sugerindo a existência de interações bióticas importantes para a manutenção do fluxo gênico. Registramos 14 espécies ameaçadas de extinção, dentre as quais duas raras (Trigynaea oblongifolia e Trattinnickia ferruginea) e duas indicadoras de florestas maduras (Trattinnickia ferruginea e Virola bicuhyba). Confirmamos a importância de áreas-chave para a conservação da biodiversidade e da FESD Atlântica localizada em cotas altitudinais de 0-1.000 m, a qual merece atenção dos conservacionistas por apresentarem alta riqueza de espécies e elevado número de espécies endêmicas e ameaçadas.

The high-spin structures of the N = 81 isotones 135Xe and 137Ba are investigated after multinucleontransfer (MNT) and fusion-evaporation reactions. Both nuclei are populated in (i) 136Xe+238U and (ii) 136Xe+208Pb MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii), in the 136Xe+198Pt MNT reaction employing the -ray array GAMMASPHERE in combination with the gas detector array Chico, and (iv) via a 11B+130Te fusion-evaporation reaction. The high-spin level schemes of 135Xe and 137Ba are considerably extended to higher energies. The 2058-keV (19=2 ) state in 135Xe is identified as an isomer, completing the systematics for the N = 81 isotones. Its half-life is measured to be 8.6(10) ns, corresponding to a transition probability of B(E2; 19=2 ! 15=2 ) = 0:539(69) W.u. Latest shell model calculations considering 132Sn as a closed core reproduce the experimental findings and provide guidance to the interpretation of the new levels. The experimentally deduced reduced quadrupole transition probabilities of the isomeric states are compared to shell-model predictions.

The isovector giant dipole resonance (IVGDR) $\ensuremath{\gamma}$ decay was measured in the compound nuclei $^{80}\mathrm{Zr}$ and $^{81}\mathrm{Rb}$ at an excitation energy of ${E}^{*}=54$ MeV. The fusion reaction $^{40}\mathrm{Ca}+^{40}\mathrm{Ca}$ at ${E}_{\mathrm{beam}}=136$ MeV was used to form the compound nucleus $^{80}\mathrm{Zr}$, while the reaction $^{37}\mathrm{Cl}+^{44}\mathrm{Ca}$ at ${E}_{\mathrm{beam}}=95$ MeV was used to form the compound nucleus $^{81}\mathrm{Rb}$ at the same excitation energy. The IVGDR parameters extracted from the analysis were compared with the ones found at higher excitation energy (${E}^{*}=83$ MeV). The comparison allows one to observe two different nuclear mechanisms: (i) the IVGDR intrinsic width remains constant with the excitation energy in the nucleus $^{81}\mathrm{Rb}$; (ii) the isospin-violating spreading width (i.e., Coulomb spreading width) remains constant with the excitation energy in the nucleus $^{80}\mathrm{Zr}$. The experimental setup used for the $\ensuremath{\gamma}$-ray detection was composed by the AGATA demonstrator array coupled to the large-volume ${\mathrm{LaBr}}_{3}$:Ce detectors of the ${\mathrm{HECTOR}}^{+}$ array.

The study of nuclear cluster states bound by valence neutrons is a field of recent large interest. In particular, it is interesting to study the pre-formation of α-clusters in α-conjugate nuclei and the dynamical condensation of clusters during nuclear reactions. The NUCL-EX collaboration (INFN, Italy) is carrying out a research campaign studying preequilibrium emission of light charged particles and cluster properties of light and medium mass nuclei. For this purpose, a comparative study of the three nuclear reactions: O 16 + Si 30 , O 18 + Si 28 and F 19 + 27Al, has been recently carried out using the GARFIELD+RCo 4π setup. After a general introduction on the experimental campaign, the preliminary results for the three systems are presented.

EXILL experimental campaign; International audience; The level scheme of 96Y was significantly extended and a new 201 ns isomer was located at 1655 keV excitation energy, with spin-parity assignment of 5± or 6−. The isomer decays to spherical low-spin structure by transitions with large hindrance and is fed by a short cascade which resembles the beginning of a rotational band. This is in analogy with the feeding and decay pattern of the 4− isomer in 98Y, here confirmed, by lifetime analysis, as a bandhead of a rotational structure with sizable deformation. It is suggested that the new isomer in 96Y arises from a shape change between deformed and spherical configurations, which indicates the appearance of deformation already at N = 57 in the yttrium chain. The experimental findings for 96Y are strengthened by theoretical calculations based on the complex Excited Vampir model.

International audience; The study of nuclear cluster states bound by valence neutrons is a field of recent large interest. In particular, it is important to study the pre-formation of α-clusters in α-conjugate nuclei and the dynamical condensation of clusters during nuclear reactions [1–5]. The NUCL–EX collaboration has recently initiated an experimental campaign of exclusive measurements of fusion–evaporation reactions with light nuclei as interacting partners. In collisions involving light systems, the low expected multiplicity of fragments increases the probability of achieving a quasi-complete reconstruction of the event. In particular the formation and decay modes of an excited 24Mg system have been studied through two different reactions, 12C (95 MeV)+ 12C and 14N (80.7 MeV)+ 10B, which have been used to produce fused systems with nearly the same mass and excitation energy (~60 MeV). In particular, even the de-excitation of the Hoyle state in 12C have been studied, both in peripheral (projectiles de-excitation) and in central collisions (six α-particles channel). Moreover, a research campaign studying pre-equilibrium emission of light charged particles and cluster properties of light and medium-mass nuclei has been carried out. For this purpose, a comparative study of the three nuclear systems 18O+28Si, 16O+30Si and 19F+27Al has been recently studied using the GARFIELD+RCo 4π setup [6]. The experimental data are compared with the predictions of simulated events generated with the statistical models (GEMINI++ and HFl) and through dynamical models like Stochastic Mean Field (SMF) and Antisymmetrized Molecular Dynamics (AMD) and filtered with a software replica of our apparatus in order to take into account the experimental conditions.

Pre-equilibrium emissions affect the production of excited systems in nuclear reactions, thus modifying their properties which enter as input parameters in the comparison with statistical models. In this contribution, we discuss this subject referring to recent results from experiments performed at Legnaro National Laboratories (Italy) with the GARFIELD apparatus complemented with other detectors. ispartof: Acta Physica Polonica B vol:48 issue:3 pages:635-639 ispartof: location:Zakopane: POLAND status: published

International audience; The multi-nucleon transfer reaction mechanism was used to produce and study nuclei in the vicinity of 208Pb. This mass region is a test case for the nuclear shell model. The mass identification of the fragments was performed with the large acceptance magnetic spectrometer VAMOS++ coupled to the AGATA γ-tracking array. This experiment aimed to determine both lifetimes and gyromagnetic ratios of excited states with the Cologne plunger device. The analysis indicates promising results with the possibility to determine several new lifetimes in this region.

International audience; The level scheme of the neutron-rich 94Y isotope has been extended up to the 5324 keV excitation energy. During the analysis, a structure above the previously known (5+) isomer, at 1202 keV, was extended by employing multifold gamma-ray coincidence relationships measured with the EXILL array. For some of the new states, the spin-parity assignment has been proposed on the basis of gamma angular correlations and shell-model considerations. The newly identified structure is characteristic of spherical or nearly spherical configurations and no evidence for new isomers and rotational patterns was found.

We present a new method for the measurement of very small Γ γ partial width that is important for the synthesis of elements in astrophysics. The method is based on the simultaneous detection of scattered beam, residual nucleus and decay γ rays. This method is optimized for the use of the CHIMERA detector at LNS. Experimental details are described.

Nuclear level densities and $\gamma$-ray strength functions of $^{56,57}$Fe have been extracted from proton-$\gamma$ coincidences. A low-energy enhancement in the $\gamma$-ray strength functions up to a factor of 30 over common theoretical E1 models is confirmed. Angular distributions of the low-energy enhancement in $^{57}$Fe indicate its dipole nature, in agreement with findings for $^{56}$Fe. The high statistics and the excellent energy resolution of the large-volume LaBr$_{3}$(Ce) detectors allowed for a thorough analysis of $\gamma$ strength as function of excitation energy. Taking into account the presence of strong Porter-Thomas fluctuations, there is no indication of any significant excitation-energy dependence in the $\gamma$-ray strength function, in support of the generalized Brink-Axel hypothesis., Comment: 24 pages, 17 figures, accepted for publication in J. Phys. G: Nucl. Phys; Special Issue

The γ -ray emission from the dynamical dipole formed in heavy-ion collisions during the process leading to fusion was measured for the N/Z asymmetric reaction 16 O + 116 Sn at beam energies of 8.1 and 15.6 MeV/nucleon. High-energy γ -rays and charged particles were measured in coincidence with the heavy recoiling residual nuclei. The data are compared with those from the N/Z symmetric reaction 64 Ni + 68 Zn at bombarding energies of 4.7 and 7.8 MeV/nucleon, leading to the same CN with the same excitation energies as calculated from kinematics. The measured yield of the high-energy γ -rays from the 16 O-induced reaction is found to exceed that of the thermalized CN and the excess yield increases with bombarding energy. The data are in rather good agreement with the predictions for the dynamical dipole emission based on the Boltzmann–Nordheim–Vlasov model. In addition, a comparison with existing data in the same mass region is performed to extract information on the dipole moment dependence.

International audience; The structure of the 131Sn nucleus was studied at the Institut LaueLangevin by prompt-delayed γ-ray spectroscopy across the 0.3 µs, 23/2− isomeric state at 4670 keV, following cold-neutron-induced fission of 235U and 241Pu targets. New γ-ray transitions are observed and the results are compared with theoretical calculations performed with the Hybrid Configuration Mixing Model. The latter suggests that the majority of the states can be well-described in terms of couplings between single-hole degrees of freedom and 132Sn core excitations, pointing to a robust neutron shell closure at N = 82.

© 2019 Jagellonian University. All Rights Reserved. The breaking of isospin symmetry caused by the Coulomb interaction can be measured by the study of E1 γ decay. The Isovector Giant Dipole Resonance (IVGDR) was measured in 60 Zn and 62 Zn at two different excitation energies E ∗ = 47 MeV and E ∗ = 58 MeV with the goal of deducing the isospin mixing term. A fusion–evaporation reaction, with a beam of 32 S and a target of 28 Si, was used to produce 60 Zn. We also produced the compound nucleus 62 Zn using the reaction 32 S + 30 Si. This last reaction is required because, for the produced nucleus, the statistical model analysis is much less sensitive to the isospin mixing, and this allows to extract the GDR parameters and use them for isospin mixing sensitive reaction populating neighboring nucleus with N = Z. The experimental setup was composed of GALILEO array (germanium detectors) coupled to the large-volume LaBr 3 :Ce detectors for the γ-rays measuring and by two ancillary arrays, EUCLIDES and the Neutron Wall for the detection of particles and neutrons, respectively. An overview on the ongoing analysis and on preliminary results is presented. ispartof: ACTA PHYSICA POLONICA B vol:50 issue:3 pages:481-486 ispartof: location:POLAND, Zakopane status: published

In a two–neutron transfer experiment, performed in Bucharest in July 2016 at sub–Coulomb barrier energy,a photon decay hindered – solely – by a nuclear shape change was identified in the 66Ni nucleus. Such a rare process, at spin zero, was clearly observed before only in actinide nuclei in the 1970’s,where fission isomers were found. The experimental findings on 66Ni have been well reproduced by the Monte Carlo Shell Model Calculations of the Tokyo group, which predict a multifaceted scenario of coexistence of spherical, oblate and prolate shapes in neutron–rich Ni isotopes. The results on 66Ni encouraged a comprehensive gamma–spectroscopy investigation of neutron–rich Ni isotopes, in particular 62Ni and 64–Ni, at IFIN–HH (Bucharest), IPN Orsay and ILL (Grenoble), employing different reaction mechanisms to pin down the wave function composition of selected excited states. The aim is to shed light on the microscopic origin of deformation in neutron–rich Ni nuclei, possibly locating other examples of “shape–isomer–like” structures inthis region.

The level structures of the N = 50 83As, 82Ge, and 81Ga isotones have been investigated by means of multi-nucleon transfer reactions. A first experiment was performed with the CLARA–PRISMA setup to identify these nuclei. A second experiment was carried out with the GASP array in order to deduce the γ-ray coincidence information. The results obtained on the high-spin states of such nuclei are used to test the stability of the N = 50 shell closure in the region of 78Ni ( Z = 28 ). The comparison of the experimental level schemes with the shell-model calculations yields an N = 50 energy gap value of 4.7(3) MeV at Z = 28 . This value, in a good agreement with the prediction of the finite-range liquid-drop model as well as with the recent large-scale shell model calculations, does not support a weakening of the N = 50 shell gap down to Z = 28 .

International audience; The decay of the one-proton valence nucleus 133Sb is studied usingthe cold-neutron induced fission of 235U and 241Pu targets. The experimentis performed at the ILL reactor in Grenoble, using a highly efficient HPGearray, also coupled to fast LaBr3(Ce) scintillators. High-spin excited statesabove the 16.6 s isomer are observed, and the lifetime of the 13/2+ and15/2+ states is measured by fast-timing techniques, revealing a complexnature of the wave functions. The experimental results are well-interpretedby a newly developed microscopic model which takes into account the couplingbetween the valence proton and excitations (both collective and noncollective)of the doubly magic 132Sn core.

K. Hadyńska-Kl¸ek et al. ; 7 pags., 3 figs., 2 tabs., Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42 were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 02+ has been obtained and the role of triaxiality in the A∼40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time. © 2016 American Physical Society, Special gratitude goes to the INFN LNL and HIL Warsaw technical staff for their support and help, in particular, the accelerator crews for providing intense and good-quality 42Ca and 32S beams. K. H.-K. acknowledges support from the Research Council of Norway under the project Grant No. 213442. T. R. R. acknowledges computing time at GSI-Darmstadt and support from Spanish MINECO under Programa Ramon y Cajal 11420 and FIS-2014-53434-P, H. N. acknowledges support from Helmholtz Association through the Nuclear Astrophysics Virtual Institute NAVI (No. VH-VI-417). We also acknowledge the support by Generalitat Valenciana, Spain, under the grant PROMETEOII/2014/019 and by the FEDER funds of the European Commission (A. Gadea), Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014-57196-C5 (A. J., A. Gadea), German Bundesministerium für Bildung und Forschung (BMBF) under Contract No. 05P12PKFNE TP4 (B. Birkenbach), the Polish National Science Centre under Projects No. DEC-2013/10/M/ST2/00427, No. DPN/N190/ AGATA/2009, No. 2011/03/B/ST2/01894, No. UMO- 2014/14/M/ST2/00738 (COPIN-INFN Collaboration), and No. 2015/17/B/ST2/01534.

The multipolarity of the main transition leading to the ground state in 210Bi was investigated using the angular correlations of γ rays. The analyzed γ -coincidence data were obtained from the 209Bi(n,γ )210Bi experiment performed at Institut Laue-Langevin Grenoble at the PF1B cold-neutron facility. The EXILL (EXOGAM at the ILL) multidetector array, consisting of 16 high-purity germanium detectors, was used to detect γ transitions. The mixing ratio of the 320-keV γ ray was defined by minimizing a multivariable χ2 function constructed from the coefficients of angular correlation functions for seven pairs of strong transitions in 210Bi. As a result, the almost pure M1 multipolarity of the 320-keV γ ray was obtained, with an E2 admixture of less than 0.6% only (95% confidence limit). Based on this multipolarity the neutron-capture cross section leading to the ground state in 210Bi, that decays in turn to radiotoxic 210Po, was determined to be within the limits 21.3(9) and 21.5(9) mb. This result is important for nuclear reactor applications.

We performed a γ -particle coincidence experiment for the 60Ni+116Sn system to investigate whether the population of the two-neutron pickup channel leading to 62Ni is mainly concentrated in the ground-state transition, as has been found in a previous work [D. Montanari et al., Phys. Rev. Lett. 113, 052501 (2014)]. The experiment has been performed by employing the PRISMA magnetic spectrometer coupled to theAdvanced Gamma Tracking Array (AGATA) demonstrator. The strength distribution of excited states corresponding to the inelastic, one- and two-neutron transfer channels has been extracted.We found that in the two-neutron transfer channel the strength to excited states corresponds to a fraction (less than 24%) of the total, consistent with the previously obtained results that the 2n channel is dominated by the ground-state to ground-state transition.

A new measurement of the dynamical dipole emission was performed in the system O-16 + Sn-116 at 12 MeV/nucleon. These data, together with those measured at 8.1 MeV/nucleon and 15.6 MeV/nucleon on the same system, provide the dependence of the dynamical dipole total emission yield on the beam energy. The energy removed by preequilibrium charged particles emission was directly measured and this made possible the direct estimation of the compound nucleus excitation energy. The experimental results show a weak increase of the dynamical dipole total yield with beam energy and they are in agreement both in trend and in absolute values with the predictions of the theoretical model based on the Boltzmann-Nordheim-Vlasov approach. The measured gamma-ray angular distribution has a dipole character but with a strong quenching probably owing to the rotation of the dipolar axis during the fusion and thermalization processes.

The low-spin structure of the 210Bi nucleus was investigated in the neutron capture experiment 209Bi(n,γ )210Bi performed at ILL Grenoble at the PF1B cold-neutron facility. By using the EXILL multidetector array, consisting of 46 high-purity germanium crystals, and γγ-coincidence technique, 64 primary γ rays were observed (40 new) and a total number of 70 discrete states (33 new) were located below the neutron binding energy in 210Bi. The analysis of the angular correlations of γ rays provided information about transitions multipolarities, which made it possible to confirm most of the previously known spin-parity assignments and helped establish new ones. The obtained experimental results were compared to shell-model calculations involving one-valence-proton, one-valence-neutron excitations outside the 208Pb core. It has been found that while up to the energy of ∼2 MeV each state observed in 210Bi has its calculated counterpart; at higher excitation energies some levels cannot be described by the valence particle couplings. These states may arise from couplings of valence particles to the 3− octupole phonon of the doubly magic 208Pb core and may serve as a testing ground for models which describe single particle-phonon excitations.

The γ decay from the high-lying states of ^140Ce excited via inelastic scattering of ^17O at a bombarding energy of 340 MeV was measured using the high-resolution AGATA-demonstrator array in coincidence with scattered ions detected in two segmented Δ E-E silicon detectors. Angular distributions of scattered ions and emitted γ rays were measured, as well as their differential cross sections. The excitation of 1^− states below the neutron separation energy is similar to the one obtained in reactions with the α isoscalar probe. The comparison between the experimental differential cross sections and the corresponding predictions using the distorted-wave Born approximation allowed us to extract the isoscalar component of identified 1^− pygmy states. For this analysis the form factor obtained by folding microscopically calculated transition densities and optical potentials was used.

A study of fusion-evaporation and (partly) fusion-fission channels for the $^{88}$Mo compound nucleus, produced at different excitation energies in the reaction $^{48}$Ti + $^{40}$Ca at 300, 450 and 600 MeV beam energies, is presented. Fusion-evaporation and fusion-fission cross sections have been extracted and compared with the existing systematics. Experimental data concerning light charged particles have been compared with the prediction of the statistical model in its implementation in the Gemini++ code, well suited even for high spin systems, in order to tune the main model parameters in a mass region not abundantly covered by exclusive experimental data. Multiplicities for light charged particles emitted in fusion evaporation events are also presented. Some discrepancies with respect to the prediction of the statistical model have been found for forward emitted $\alpha$-particles; they may be due both to pre-equilibrium emission and to reaction channels (such as Deep Inelastic Collisions, QuasiFission/QuasiFusion) different from the compound nucleus formation.

A. Vogt et al. ; 12 págs.; 9 figs.; 1 tab., Detailed spectroscopic information on the N∼82 nuclei is necessary to benchmark shell-model calculations in the region. The nuclear structure above long-lived isomers in Xe134 is investigated after multinucleon transfer (MNT) and actinide fission. Xenon-134 was populated as (i) a transfer product in Xe136+U238 and Xe136+Pb208 MNT reactions and (ii) as a fission product in the Xe136+U238 reaction employing the high-resolution Advanced Gamma Tracking Array (AGATA). Trajectory reconstruction has been applied for the complete identification of beamlike transfer products with the magnetic spectrometer PRISMA. The Xe136+Pt198 MNT reaction was studied with the γ-ray spectrometer GAMMASPHERE in combination with the gas detector array Compact Heavy Ion Counter (CHICO). Several high-spin states in Xe134 on top of the two long-lived isomers are discovered based on γγ-coincidence relationships and information on the γ-ray angular distributions as well as excitation energies from the total kinetic energy loss and fission fragments. The revised level scheme of Xe134 is extended up to an excitation energy of 5.832 MeV with tentative spin-parity assignments up to 16+. Previous assignments of states above the 7- isomer are revised. Latest shell-model calculations employing two different effective interactions reproduce the experimental findings and support the new spin and parity assignments., The research leading to these results has received funding from the German BMBF under Contract No. 05P12PKFNE TP4, from the European Union Seventh Framework Programme FP7/2007–2013 under Grant Agreement No. 262010 - ENSAR, from the Spanish Ministerio de Ciencia e Innovación under Contract No. FPA2011-29854-C04, from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014-57196-C5, from the Bonn-Cologne Graduate School of Physics and Astronomy (BCGS), from the UK Science and Technology Facilities Council (STFC), and from the US National Science Foundation (NSF). One of the authors (A. Gadea) has been supported by the Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019 and EU under the FEDER program.

The 6th International Summer School on Subatomic Physics (ISSSP) “New Frontiers of Nuclear Physics” was held at Peking University (PKU) on August 27–31, 2011. The opening ceremony was presided over...

Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich Se-84,Se-86 are investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was perform ...

The isospin mixing was deduced in the compound nucleus Zr-80 at an excitation energy of E* = 54 MeV from the gamma decay of the giant dipole resonance. The reaction Ca-40 + Ca-40 at E-beam = 136 MeV was used to form the compound nucleus in the isospin I = 0 channel, while the reaction Cl-37 + Ca-44 at E-beam = 95 MeV was used as the reference reaction. The. rays were detected with the AGATA demonstrator array coupled with LaBr3:Ce detectors. The temperature dependence of the isospin mixing was obtained and the zero-temperature value deduced. The isospin-symmetry-breaking correction delta(C) used for the Fermi superallowed transitions was extracted and found to be consistent with beta-decay data.