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Author Fernandez, A.; Hufschmidt, D.; Colaux, J.L.; Valiente-Dobon, J.J.; Godinho, V.; Jimenez de Haro, M.C.; Feria, D.; Gadea, A.; Lucas, S. doi  openurl
  Title Low gas consumption fabrication of He-3 solid targets for nuclear reactions Type Journal Article
  Year 2020 Publication Materials & Design Abbreviated Journal (up) Mater. Des.  
  Volume 186 Issue Pages 108337 - 10pp  
  Keywords He-3 solid targets; Quasistatic magnetron sputtering; Low gas consumption; Nuclear reactions; Inverse kinematics; Target stability  
  Abstract Nanoporous solids that stabilize trapped gas nanobubbles open new possibilities to fabricate solid targets for nuclear reactions. A methodology is described based on the magnetron sputtering (MS) technique operated under quasistatic flux conditions to produce such nanocomposites films with He-3 contents of up to 16 at.% in an amorphous-silicon matrix. In addition to the characteristic low pressure (3-6 Pa) needed for the gas discharge, the method ensures almost complete reduction of the process gas flow during film fabrication. The method could produce similar materials to those obtained under classical dynamic flux conditions for MS. The drastic reduction (>99.5%) of the gas consumption is fundamental for the fabrication of targets with scarce and expensive gases. Si:He-3 and W:He-3 targets are presented together with their microstructural (scanning and transmission electron microscopy, SEM and TEM respectively) and compositional (Ion Beam Analysis, IBA) characterization. The He-3 content achieved was over 1 x 10(18) at/cm(2) for film thicknesses between 1.5 and 3 μm for both Si and W matrices. First experiments to probe the stability of the targets for nuclear reaction studies in inverse kinematics configurations are presented.  
  Address [Fernandez, Asuncion; Hufschmidt, Dirk; Godinho, Vanda; Jimenez de Haro, Maria C.; Feria, David] Univ Seville, CSIC, Inst Ciencia Mat Sevilla, Avda Amer Vespucio 49, Seville 41092, Spain, Email: asuncion@icmse.csic.es  
  Corporate Author Thesis  
  Publisher Elsevier Sci Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0264-1275 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000505221700053 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4239  
Permanent link to this record
 

 
Author Cederwall, B. et al; Algora, A.; Gadea, A. url  doi
openurl 
  Title Evidence for a spin-aligned neutron-proton paired phase from the level structure of Pd-92 Type Journal Article
  Year 2011 Publication Nature Abbreviated Journal (up) Nature  
  Volume 469 Issue 7328 Pages 68-71  
  Keywords  
  Abstract Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.  
  Address [Cederwall, B.; Moradi, F. Ghazi; Back, T.; Johnson, A.; Blomqvist, J.; Andgren, K.; Lagergren, K.; Liotta, R.; Qi, C.; Hadinia, B.; Khaplanov, A.; Persson, A.; Sandzelius, M.] Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden, Email: cederwall@nuclear.kth.se  
  Corporate Author Thesis  
  Publisher Nature Publishing Group Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000285921600032 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 588  
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Author AGATA Collaboration; Doncel, M.; Recchia, F.; Quintana, B.; Gadea, A.; Farnea, E. doi  openurl
  Title Experimental test of the background rejection, through imaging capability, of a highly segmented AGATA germanium detector Type Journal Article
  Year 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 622 Issue 3 Pages 614-618  
  Keywords Gamma spectroscopy; Gamma tracking; Imaging; Position-sensitive germanium detectors  
  Abstract The development of highly segmented germanium detectors as well as the algorithms to identify the position of the interaction within the crystal opens the possibility to locate the gamma-ray source using Compton imaging algorithms. While the Compton-suppression shield, coupled to the germanium detector in conventional arrays, works also as an active filter against the gamma rays originated outside the target, the new generation of position sensitive gamma-ray detector arrays has to fully rely on tracking capabilities for this purpose. In specific experimental conditions, as the ones foreseen at radioactive beam facilities, the ability to discriminate background radiation improves the sensitivity of the gamma spectrometer. In this work we present the results of a measurement performed at the Laboratori Nazionali di Legnaro (LNL) aiming the evaluation of the AGATA detector capabilities to discriminate the origin of the gamma rays on an event-by-event basis. It will be shown that, exploiting the Compton scattering formula, it is possible to track back gamma rays coming from different positions, assigning them to specific emitting locations. These imaging capabilities are quantified for a single crystal AGATA detector.  
  Address [Doncel, M.; Quintana, B.] Univ Salamanca, Lab Radiac Ionizantes, E-37008 Salamanca, Spain, Email: doncel@usal.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282562700017 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 257  
Permanent link to this record
 

 
Author AGATA Collaboration; Farnea, E.; Recchia, F.; Bazzacco, D.; Kroll, T.; Podolyak, Z.; Quintana, B.; Gadea, A. doi  openurl
  Title Conceptual design and Monte Carlo simulations of the AGATA array Type Journal Article
  Year 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 621 Issue 1-3 Pages 331-343  
  Keywords Monte Carlo code; gamma-ray tracking array  
  Abstract The aim of the Advanced GAmma Tracking Array (AGATA) project is the construction of an array based on the novel concepts of pulse shape analysis and gamma-ray tracking with highly segmented Ge semiconductor detectors. The conceptual design of AGATA and its performance evaluation under different experimental conditions has required the development of a suitable Monte Carlo code. In this article, the description of the code as well as simulation results relevant for AGATA, are presented.  
  Address [Farnea, E.; Recchia, F.; Bazzacco, D.] Ist Nazl Fis Nucl, Sez Padova, Padua, Italy, Email: Enrico.Farnea@pd.infn.it  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000281109100045 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 390  
Permanent link to this record
 

 
Author AGATA Collaboration (Soderstrom, P.A. et al); Gadea, A. doi  openurl
  Title Interaction position resolution simulations and in-beam measurements of the AGATA HPGe detectors Type Journal Article
  Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 638 Issue 1 Pages 96-109  
  Keywords gamma-ray tracking; AGATA; Monte Carlo simulations; HPGe detectors; Fusion-evaporation reactions  
  Abstract The interaction position resolution of the segmented HPGe detectors of an AGATA triple cluster detector has been studied through Monte Carlo simulations and in an in-beam experiment. A new method based on measuring the energy resolution of Doppler-corrected gamma-ray spectra at two different target to detector distances is described. This gives the two-dimensional position resolution in the plane perpendicular to the direction of the emitted gamma-ray. The gamma-ray tracking was used to determine the full energy of the gamma-rays and the first interaction point, which is needed for the Doppler correction. Five different heavy-ion induced fusion-evaporation reactions and a reference reaction were selected for the simulations. The results of the simulations show that the method works very well and gives a systematic deviation of <1 mm in the FVVHM of the interaction position resolution for the gamma-ray energy range from 60 keV to 5 MeV. The method was tested with real data from an in-beam measurement using a (30)5i beam at 64 MeV on a thin C-12 target. Pulse-shape analysis of the digitized detector waveforms and gamma-ray tracking was performed to determine the position of the first interaction point, which was used for the Doppler corrections. Results of the dependency of the interaction position resolution on the gamma-ray energy and on the energy, axial location and type of the first interaction point, are presented. The FVVHM of the interaction position resolution varies roughly linearly as a function of gamma-ray energy from 8.5 mm at 250 key to 4 mm at 1.5 MeV, and has an approximately constant value of about 4 mm in the gamma-ray energy range from 1.5 to 4 MeV.  
  Address [Soderstrom, P. -A.; Nyberg, J.; Al-Adili, A.; Atac, A.; Veyssiere, C.] Uppsala Univ, Dept Phys & Astron, SE-75121 Uppsala, Sweden, Email: P-A.Soderstrom@physics.uu.se  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000290082600015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 619  
Permanent link to this record
 

 
Author AGATA and PRISMA Collaborations (Gadea, A. et al) doi  openurl
  Title Conceptual design and infrastructure for the installation of the first AGATA sub-array at LNL Type Journal Article
  Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 654 Issue 1 Pages 88-96  
  Keywords AGATA; PRISMA spectrometer; DANTE heavy-ion detector; HELENA multiplicity filter; Cologne plunger; TRACE Si detector  
  Abstract The first implementation of the AGATA spectrometer consisting of five triple germanium detector clusters has been installed at Laboratori Nazionali di Legnaro, INFN. This setup has two major goals, the first one is to validate the gamma-tracking concept and the second is to perform an experimental physics program using the stable beams delivered by the Tandem-PIAVE-ALPI accelerator complex. A large variety of physics topics will be addressed during this campaign, aiming to investigate both neutron and proton-rich nuclei. The setup has been designed to be coupled with the large-acceptance magnetic-spectrometer PRISMA. Therefore, the in-beam prompt gamma rays detected with AGATA will be measured in coincidence with the products of multinucleon-transfer and deep-inelastic reactions measured by PRISMA. Moreover, the setup is versatile enough to host ancillary detectors, including the heavy-ion detector DANTE, the gamma-ray detector array HELENA, the Cologne plunger for lifetime measurements and the Si-pad telescope TRACE. In this paper the design; characteristics and performance figures of the setup will be described.  
  Address [Gadea, A] Univ Valencia, CSIC, IFIC, Inst Fis Corpuscular IFIC, E-46003 Valencia, Spain, Email: gadea@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000295765100014 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 791  
Permanent link to this record
 

 
Author AGATA Collaboration (Akkoyun, S. et al); Algora, A.; Barrientos, D.; Domingo-Pardo, C.; Egea, F.J.; Gadea, A.; Huyuk, T.; Kaci, M.; Mendez, V.; Rubio, B.; Salt, J.; Tain, J.L. url  doi
openurl 
  Title AGATA-Advanced GAmma Tracking Array Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 668 Issue Pages 26-58  
  Keywords AGATA; gamma-Ray spectroscopy; gamma-Ray tracking; HPGe detectors; Digital signal processing; Pulse-shape and gamma-ray tracking algorithms; Semiconductor detector performance and simulations  
  Abstract The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-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 gamma 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 gamma-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.  
  Address [Boston, A. J.; Boston, H. C.; Colosimo, S.; Cooper, R. J.; Cresswell, J. R.; Dimmock, M. R.; Filmer, F.; Grint, A. N.; Harkness, L. J.; Judson, D. S.; Mather, A. R.; Moon, S.; Nelson, L.; Nolan, P. J.; Norman, M.; Oxley, D. C.; Rigby, S.; Sampson, J.; Scraggs, D. P.; Seddon, D.; Slee, M.; Stanios, T.; Thornhill, J.; Unsworth, C.; Wells, D.] Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England, Email: a.j.boston@liverpool.ac.uk  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000300864200005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 923  
Permanent link to this record
 

 
Author Jaworski, G.; Palacz, M.; Nyberg, J.; de Angelis, G.; de France, G.; Di Nitto, A.; Egea, F.J.; Erduran, M.N.; Erturk, S.; Farnea, E.; Gadea, A.; Gonzalez, V.; Gottardo, A.; Huyuk, T.; Kownacki, J.; Pipidis, A.; Roeder, B.; Soderstrom, P.A.; Sanchis, E.; Tarnowski, R.; Triossi, A.; Wadsworth, R.; Valiente-Dobon, J.J. doi  openurl
  Title Monte Carlo simulation of a single detector unit for the neutron detector array NEDA Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 673 Issue Pages 64-72  
  Keywords Monte Carlo simulation; BC501; BC501A; BC537; Liquid scintillator; Neutron detector; Geant4; NEDA  
  Abstract A study of the dimensions and performance of a single detector of the future neutron detector array NEDA was performed by means of Monte Carlo simulations, using GEANT4. Two different liquid scintillators were evaluated: the hydrogen based BC501A and the deuterated BC537. The efficiency and the probability that one neutron will trigger a signal in more than one detector were investigated as a function of the detector size. The simulations were validated comparing the results to experimental measurements performed with two existing neutron detectors, with different geometries, based on the liquid scintillator BC501.  
  Address [Jaworski, G.; Palacz, M.; Kownacki, J.; Tarnowski, R.] Univ Warsaw, Heavy Ion Lab, PL-02093 Warsaw, Poland, Email: palacz@slcj.uw.edu.pl  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000301813500009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 944  
Permanent link to this record
 

 
Author AGATA Collaboration; Doncel, M.; Quintana, B.; Gadea, A.; Recchia, F.; Farnea, E. doi  openurl
  Title Background rejection capabilities of a Compton imaging telescope setup with a DSSD Ge planar detector and AGATA Type Journal Article
  Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 648 Issue Pages S131-S134  
  Keywords gamma-Spectroscopy; Gamma tracking; Imaging; Position-sensitive germanium detectors  
  Abstract In this work, we show the first Monte Carlo results about the performance of the Ge array which we propose for the DESPEC experiment at FAIR, when the background algorithm developed for AGATA is applied. The main objective of our study is to characterize the capabilities of the gamma-spectroscopy system, made up of AGATA detectors in a semi-spherical distribution covering a 1 pi solid angle and a set of planar Ge detectors in a daisy configuration, to discriminate between gamma sources placed at different locations.  
  Address [Doncel, M.; Quintana, B.] Univ Salamanca, Lab Radiac Ionizantes, E-37008 Salamanca, Spain, Email: doncel@usal.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000305376900035 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1071  
Permanent link to this record
 

 
Author AGATA Collaboration; Domingo-Pardo, C.; Bazzacco, D.; Doornenbal, P.; Farnea, E.; Gadea, A.; Gerl, J.; Wollersheim, H.J. doi  openurl
  Title Conceptual design and performance study for the first implementation of AGATA at the in-flight RIB facility of GSI Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal (up) Nucl. Instrum. Methods Phys. Res. A  
  Volume 694 Issue Pages 297-312  
  Keywords gamma-Ray spectroscopy; Tracking; Monte Carlo  
  Abstract The main objective of the Advanced GAmma Tracking Array (AGATA) is the investigation of the structure of exotic nuclei at the new generation of RIB facilities. As part of the preparatory phase for FAIR-NUSTAR, AGATA is going to be installed at the FRS fragmentation facility of the GSI centre for an experimental campaign to be performed in 2012 and 2013. Owing to its gamma-ray tracking capabilities and the envisaged enhancement in resolving power, a series of in-flight gamma-ray spectroscopy experiments are being planned. The present work describes the conceptual design of this first implementation of AGATA at GSI-FRS, and provides information about the expected performance figures. According to the characteristics of each particular experiment, it is foreseen that the target-array distance is adjusted in order to achieve the optimum compromise between detection efficiency and energy resolution, or to cover an specific angular range of the emitted electromagnetic radiation. Thus, a comprehensive Monte Carlo study of the detection sensitivity in terms of photopeak efficiency, resolution and peak-to-total ratio, as a function of the target-array distance is presented. Several configurations have been investigated, and MC-calculations indicate that a remarkable enhancement in resolving power can be achieved when double-cluster AGATA detectors are developed and implemented. Several experimental effects are also investigated. This concerns the impact of passive materials between the target and the array, the angular distribution of the detection efficiency and the influence of target thickness effects and transition lifetimes in the attainable detection sensitivity. A short overview on half-life measurements via lineshape effects utilizing AGATA is also presented. (C) 2012 Elsevier B.V. All rights reserved.  
  Address [Domingo-Pardo, C.; Gadea, A.] Univ Valencia, CSIC, IFIC, Valencia, Spain, Email: domingo@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000311020500041 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1240  
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