| 1. |
- Akkoyun, S., et al.
(författare)
-
AGATA - Advanced GAmma Tracking Array
- 2012
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 0167-5087 .- 1872-9576. ; 668, s. 26-58
-
Tidskriftsartikel (refereegranskat)abstract
- The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation γ-ray spectrometer. AGATA is based on the technique of γ-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a γ ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of γ-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector- response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer. © 2011 Elsevier B.V. All rights reserved.
|
|
| 2. |
- Das, P., et al.
(författare)
-
Study of exotic decay of Cs isotope close to the proton drip line
- 2020
-
Ingår i: 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK. - : IOP Publishing. - 1742-6588. ; 1643
-
Konferensbidrag (refereegranskat)abstract
- The neutron-deficient 115Cs was produced at ISOLDE, CERN by spallation reaction using 1.4 GeV proton on LaC2 target. The exotic decay modes were studied by using a charged particle array (DSSD and pad detectors) and a γ-detector array (four Clovers) at the ISOLDE decay station (IDS). In this report, results on observed β-delayed particle emission from 115Cs, a nucleus close to proton drip line, is presented. By measuring the time distribution in the delayed proton spectrum, the half-life of the ground state of 115Cs was extracted. The obtained half-life is in agreement with previous reported value. For the first time, the p-unbound states of 115Xe, obtained by measuring beta-delayed protons from 115Cs is reported.
|
|
| 3. |
- Stryjczyk, M., et al.
(författare)
-
Decay studies of the long-lived states in Tl 186
- 2020
-
Ingår i: Physical Review C. - 2469-9985. ; 102:2
-
Tidskriftsartikel (refereegranskat)abstract
- Decay spectroscopy of the long-lived states in Tl186 has been performed at the ISOLDE Decay Station at ISOLDE, CERN. The α decay from the low-spin (2-) state in Tl186 was observed for the first time and a half-life of 3.4-0.4+0.5 s was determined. Based on the α-decay energy, the relative positions of the long-lived states were fixed, with the (2-) state as the ground state, the 7(+) state at 77(56) keV, and the 10(-) state at 451(56) keV. The level scheme of the internal decay of the Tl186(10(-)) state [T1/2=3.40(9) s], which was known to decay solely through emission of 374-keV γ-ray transition, was extended and a lower limit for the β-decay branching bβ>5.9(3)% was determined. The extracted retardation factors for the γ decay of the 10(-) state were compared to the available data in neighboring odd-odd thallium isotopes indicating the importance of the πd3/2 shell in the isomeric decay and significant structure differences between Tl184 and Tl186.
|
|
| 4. |
- Banu, A, et al.
(författare)
-
108Sn Studied with Intermediate-energy Coulomb Excitation
- 2005
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:6
-
Tidskriftsartikel (refereegranskat)abstract
- The unstable neutron-deficient Sn-108 isotope has been studied in inverse kinematics by intermediate-energy Coulomb excitation using the RISING/FRS experimental setup at GSI. This is the highest Z nucleus studied so far with this method. Its reduced transition probability B (E2;0(g.s.)(+)-> 2(1)(+)) has been measured for the first time. The extracted B(E2) value of 0.230(57)e(2) b(2) has been determined relative to the known value in the stable Sn-112 isotope. The result is discussed in the framework of recent large-scale shell model calculations performed with realistic effective interactions. The roles of particle-hole excitations of the Sn-100 core and of the Z=50 shell gap for the E2 polarization are investigated.
|
|
| 5. |
- Das, P., et al.
(författare)
-
Exotic decay of 115Cs
- 2023
-
Ingår i: Physical Review C. - 2469-9985. ; 108:6
-
Tidskriftsartikel (refereegranskat)abstract
- The detailed study of the β+/EC decay of the very neutron-deficient and alpha-unbound nucleus 115Cs is presented. The measurement was performed at the ISOLDE, CERN where delayed charged particles and γ rays were detected. The observed delayed γ rays are in agreement with the previously reported characteristics γ rays of 115Xe. Based on the experimental observations, the tentative ground-state spin of 115Cs is suggested to be 7/2+ or 9/2+. Furthermore, the measured decay branching ratio of delayed protons exceeds the previously reported value. Additionally, new delayed α-branching ratio and several reconstructed proton and α-unbound excited states of 115Xe are being reported for the first time. The properties of proton-unbound states at excitation energies from 3.9–7.9 MeV have been obtained by fitting the delayed proton spectrum via the Bayesian method. The measured lifetimes of these proton-unbound states are in the order of zeptoseconds.
|
|
| 6. |
- IDS Collaboration, HASH(0x3dac240), et al.
(författare)
-
Beta-delayed proton emission from 20Mg
- 2016
-
Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 52:10, s. 304-
-
Tidskriftsartikel (refereegranskat)abstract
- Beta-delayed proton emission from 20 Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in 20 Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in 20 Na is observed. This may allow studies of the 4032.9(2.4)keV resonance in 19 Ne through the beta decay of 20 Mg, which is important for the astrophysically relevant reaction 15O(?,?)19Ne. Beta-delayed protons were used to obtain a more precise value for the half-life of 20 Mg, 91.4(1.0)ms.
|
|
| 7. |
- Kirsebom, O. S., et al.
(författare)
-
First Accurate Normalization of the β -delayed α Decay of N 16 and Implications for the C 12 (α,γ) O 16 Astrophysical Reaction Rate
- 2018
-
Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 121:14
-
Tidskriftsartikel (refereegranskat)abstract
- Published by the American Physical Society. The C12(α,γ)O16 reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced α width, γ11, of the bound 1- level in O16 is particularly important to determine the cross section. The magnitude of γ11 is determined via sub-Coulomb α-transfer reactions or the β-delayed α decay of N16, but the latter approach is presently hampered by the lack of sufficiently precise data on the β-decay branching ratios. Here we report improved branching ratios for the bound 1- level [bβ,11=(5.02±0.10)×10-2] and for β-delayed α emission [bβα=(1.59±0.06)×10-5]. Our value for bβα is 33% larger than previously held, leading to a substantial increase in γ11. Our revised value for γ11 is in good agreement with the value obtained in α-transfer studies and the weighted average of the two gives a robust and precise determination of γ11, which provides significantly improved constraints on the C12(α,γ) cross section in the energy range relevant to hydrostatic He burning.
|
|
| 8. |
|
|
| 9. |
- Söderström, Pär-Anders, et al.
(författare)
-
Spectroscopy of neutron-rich Dy-168,Dy-170 : Yrast band evolution close to the NpNn valence maximum
- 2010
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 81:3, s. 034310-
-
Tidskriftsartikel (refereegranskat)abstract
- The yrast sequence of the neutron-rich dysprosium isotope Dy-168 has been studied using multinucleon transfer reactions following collisions between a 460-MeV Se-82 beam and an Er-170 target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2(+) and 4(+) members of the previously measured ground-state rotational band of Dy-168 have been confirmed and the yrast band extended up to 10(+). A tentative candidate for the 4(+) -> 2(+) transition in Dy-170 was also identified. The data on these nuclei and on the lighter even-even dysprosium isotopes are interpreted in terms of total Routhian surface calculations and the evolution of collectivity in the vicinity of the proton-neutron valence product maximum is discussed.
|
|
| 10. |
- de Angelis, G., et al.
(författare)
-
Coherent proton-neutron contribution to octupole correlations in the neutron-deficient Xe-114 nucleus
- 2002
-
Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 535:04-jan, s. 93-102
-
Tidskriftsartikel (refereegranskat)abstract
- Gamma ray linear polarization and picosecond lifetimes have been measured for levels in the neutron deficient nucleus Xe-114 using the EUROBALL IV spectrometer and the Cologne plunger device. The EUCLIDES Si-ball was used to improve the reaction channel selectivity. The linear polarization results have, for the first time, unambiguously determined the electromagnetic character of the dipole transitions de-exciting the negative parity level sequence, providing clear evidence for enhanced octupole collectivity. The discovery of two E3 transitions and the measurement of the lifetimes of the states depopulated by these transitions have allowed a quantitative determination of the octupole collectivity in the A approximate to 112 mass region. The large measured B(E3) values, close to approximate to 70 W.u., are among the strongest observed hitherto and indicate a coherent proton-neutron contribution to the octupole moment.
|
|
| 11. |
|
|
| 12. |
- Lenzi, SM, et al.
(författare)
-
Coulomb energy differences in T=1 mirror rotational bands in Fe-50 and Cr-50 - art. no. 122501
- 2001
-
Ingår i: PHYSICAL REVIEW LETTERS. - : AMERICAN PHYSICAL SOC. - 0031-9007. ; 8712:12, s. 2501-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Gamma rays from the N = Z - 2 nucleus Fe-50 have been observed, establishing the rotational ground state band up to the state J(pi) = 11(+) at 6.994 MeV excitation energy. The experimental Coulomb energy differences, obtained by comparison with the isobar
|
|
| 13. |
- Spolaore, P., et al.
(författare)
-
Identification and study of the very neutron deficient nuclide I-111 : search for octupole correlations in the region of N approximate to Z approximate to 56
- 2001
-
Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 682, s. 387C-393C
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the neutron-deficient nuclide I-111 have been populated with the fusion reaction Ni-58 + Ni-58 at a beam energy of 210 MeV, in an experiment performed at the Tandem Accelerator of the Laboratori Nazionali di Legnaro. The gamma spectrometer GASP was used in time coincidence with the ISIS Si-ball and the CAMEL recoil mass spectrometer for the positive identification of the nuclide. Gamma transitions and structure details previously attributed to I-111 by Other authors are only partially confirmed. The obtained level scheme includes new rotational bands and a new low lying structure which suggests the presence of octupole correlations at predicted rotational frequency values.
|
|
| 14. |
- Tack, LJW, et al.
(författare)
-
Management of Gonads in Adults with Androgen Insensitivity: An International Survey
- 2018
-
Ingår i: Hormone research in paediatrics. - : S. Karger AG. - 1663-2826 .- 1663-2818. ; 90:4, s. 236-246
-
Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background:</i></b> Complete and partial androgen insensitivity syndrome (CAIS, PAIS) are associated with an increased risk of gonadal germ cell cancer (GGCC). Recent guidelines recommend gonadectomy in women with CAIS in late adolescence. Nevertheless, many adult women prefer to retain their gonads. <b><i>Aims:</i></b> This study aims to explore attitudes towards gonadectomy in AIS in centres around the world, estimate the proportion of adults with retained gonads and/or who developed GGCC, and explore reasons for declining gonadectomy. <b><i>Methods:</i></b> A survey was performed among health care professionals who use the International DSD Registry (I-DSD). <b><i>Results:</i></b> Data were provided from 22 centres in 16 countries on 166 women (CAIS) and 26 men (PAIS). In CAIS, gonadectomy was recommended in early adulthood in 67% of centres; 19/166 (11.4%) women refused gonadectomy. Among 142 women who had gonadectomy, evidence of germ cell neoplasm in situ (GCNIS), the precursor of GGCC, was reported in 2 (1.4%) out of 8 from whom pathology results were formally provided. Nine out of 26 men with PAIS (34.6%) had retained gonads; 11% of centres recommended routine gonadectomy in PAIS. <b><i>Conclusion:</i></b> Although development of GGCC seems rare, gonadectomy after puberty is broadly recommended in CAIS; in PAIS this is more variable. Overall, our data reflect the need for evidence-based guidelines regarding prophylactic gonadectomy in AIS.
|
|
| 15. |
- Andreoiu, Corina, et al.
(författare)
-
First Identification of Excited States in 59Zn
- 2002
-
Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 15, s. 459-462
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states in 59Zn were observed for the first time following the fusion-evaporation reaction 24Mg + 40Ca at a beam energy of 60 MeV. The GASP array in conjunction with the ISIS Silicon ball and the NeutronRing allowed for the detection of n-rays in coincidence with evaporated light particles. The mirror symmetry of 59Zn and 59Cu is discussed.
|
|
| 16. |
- DiJulio, Douglas, et al.
(författare)
-
Electromagnetic properties of vibrational bands in Er-170
- 2011
-
Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 47:2, s. 25-
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states of the nucleus Er-170 have been studied by Coulomb excitation using the GASP gamma-ray detector system at the Laboratori Nazionali di Legnaro. The ground-state band along with a low-lying K-pi = 0(+) band and gamma-vibrational band were populated during the experiment. Based on the measured gamma-ray yields, a set of interband and intraband matrix elements has been extracted using the Coulomb excitation code GOSIA. The resulting E2 matrix elements are compared to collective model predictions.
|
|
| 17. |
- du Rietz, Rickard, et al.
(författare)
-
Effective Charges in the fp Shell
- 2004
-
Ingår i: Physical Review Letters. - 1079-7114. ; 93:22
-
Tidskriftsartikel (refereegranskat)abstract
- Following the heavy-ion fusion-evaporation reaction S-32+Mg-24 at 95 MeV beam energy the lifetimes of analogue states in the T-z=+/-1/2 A=51 mirror nuclei Fe-51 and Mn-51 have been measured using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The deduced B(E2;27/2(-)-->23/2(-)) values afford a unique opportunity to probe isoscalar and isovector polarization charges and to derive effective proton and neutron charges, epsilon(p) and epsilon(n), in the fp shell. A comparison between the experimental results and several different large-scale shell-model calculations yields epsilon(p)similar to1.15e and epsilon(n)similar to0.80e.
|
|
| 18. |
- du Rietz, Rickard, et al.
(författare)
-
Investigation of High-spin States in 53Fe
- 2005
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:1
-
Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reactions Si-28(S-32,1 alpha 2p1n)Fe-53 at 125 MeV and Mg-24(S-32,2p1n)Fe-53 at a 95-MeV beam energy were used to investigate excited states in Fe-53. The combination of the Gammasphere Ge detector array and ancillary devices led to the construction of an extensive level scheme comprising some 90 transitions connecting 40 states. The lifetime of the yrast 25/2(-) state and upper limits for the lifetimes of a number of additional states were determined using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The experimental results are compared to large-scale shell-model calculations using different sets of two-body matrix elements. In particular, predictions on electromagnetic decay properties such as lifetimes, branching ratios, and mixing ratios are studied in detail.
|
|
| 19. |
- Ekman, Jörgen, et al.
(författare)
-
Unusual Isospin-Breaking and Isospin-mixing Effects in the A=35 Mirror Nuclei
- 2004
-
Ingår i: Physical Review Letters. - 1079-7114. ; 92:13
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states have been studied in Ar-35 following the O-16(Mg-24,1alpha1n)Ar-35 fusion-evaporation reaction at 60 MeV using the Ge-detector array GASP. A comparison with the mirror nucleus Cl-35 shows two remarkable features: (i) A surprisingly large energy difference for the 13/2(-) states, in which the hitherto overlooked electromagnetic spin-orbit term is shown to play a major role, and (ii) a very different decay pattern for the 7/2(-) states, which provides direct evidence of isospin mixing.
|
|
| 20. |
- Gadea, A., et al.
(författare)
-
Observation of Ni-54 : Cross-conjugate symmetry in f(7/2) mirror energy differences
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:15, s. 152501-
-
Tidskriftsartikel (refereegranskat)abstract
- Gamma decays from excited states up to J(pi)=6(+) in the N=Z-2 nucleus Ni-54 have been identified for the first time. Level energies are compared with those of the isobars Co-54 and Fe-54 and of the cross-conjugate nuclei of mass A=42. The good but puzzling f(7/2) cross-conjugate symmetry in mirror and triplet energy differences is analyzed. Shell model calculations reproduce the new data but the necessary nuclear charge-dependent phenomenology is not fully explained by modern nucleon-nucleon potentials.
|
|
| 21. |
- Gadea, A., et al.
(författare)
-
Spectroscopy of heavy N=Z nuclei with GASP and EUROBALL
- 2003
-
Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 34:4, s. 2429-2438
-
Tidskriftsartikel (refereegranskat)abstract
- The coupling of big Ge-arrays like EUROBALL or GASP with ancillary detectors for the study of the structure properties of very exotic nuclei, far from the stability valley, has given outstanding results in the last years. A large fraction of the experiments performed with both arrays has been devoted to study both proton-rich and neutron-rich nuclei populated using stable beams provided by the LNL Legnaro and MeS Strasbourg accelerators. Nuclei lying close to the N = Z line are of particular interest being a laboratory where collective excitations as well as fundamental properties of the nuclear force can be tested, like isospin symmetry and isospin breaking terms, proton neutron pairing, dripline effects and coherent neutron and proton contributions to the nuclear excitations. Some of this properties are more evident (degree of isospin mixing) or can be only observed (collective effects) in heavy N = Z nuclei. In this contribution we present the experimental results obtained by our collaboration along and in the vicinity of N = Z line.
|
|
| 22. |
- Lunardi, S, et al.
(författare)
-
Highly deformed band in Nd-138
- 2004
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 69:5
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Nd-138 have been investigated with the reaction Zr-94(Ca-48,4n), using the GASP array. A new rotational band has been identified, which has close similarities with the well known highly deformed bands of the lighter Nd isotopes, and is therefore interpreted as built on the second minimum of the nuclear potential energy surface. From comparison with calculations a configuration is suggested which involves two neutrons in the i(13/2) deformation driving orbital.
|
|
