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Author Luo, X.L. et al; Agramunt, J.; Egea, F.J.; Gadea, A.; Huyuk, T. doi  openurl
  Title Test of digital neutron-gamma discrimination with four different photomultiplier tubes for the NEutron Detector Array (NEDA) Type Journal Article
  Year 2014 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 767 Issue Pages 83-91  
  Keywords Digital neutron-gamma discrimination; Liquid scintillator; Photomultiplier tube; Charge Comparison; Integrated rise-time; Time-of-flight; NEDA  
  Abstract (up) A comparative study of the neutron-gamma discrimination performance of a liquid scintillator detector BC501A coupled to four different 5 in photomultiplier tubes (ET9390kb, R11833-100, XP4512 and R4144) was carried out Both the Charge Comparison method and the Integrated Rise-Time method were implemented digitally to discriminate between neutrons and gamma rays emitted by a Cf-252 source. In both methods, the neutron-gamma discrimination capabilities of the four photomultiplier tubes were quantitatively compared by evaluating their figure-of-merit values at different energy regions between 50 keVee and 1000 keVee. Additionally, the results were further verified qualitatively using time-of-flight to distinguish gamma rays and neutrons. The results consistently show that photomultiplier tubes R11833-100 and ET9390kb generally perform best regarding neutron-gamma discrimination with only slight differences in figure-of-merit values. This superiority can be explained by their relatively higher photoelectron yield, which indicates that a scintillator detector coupled to a photomultiplier tube with higher photoelectron yield tends to result in better neutron-gamma discrimination performance. The results of this work will provide reference for the choice of photomultiplier tubes for future neutron detector arrays like NEDA.  
  Address [Luo, X. L.] Natl Univ Def Technol, Coll Mechatron & Automat, Dept Instrument Sci & Technol, Changsha, Hunan, Peoples R China, Email: luo.xiaoliang@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 WOS:000344994600012 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2011  
Permanent link to this record
 

 
Author Modamio, V.; Valiente-Dobon, J.J.; Jaworski, G.; Huyuk, T.; Triossi, A.; Egea, J.; Di Nitto, A.; Soderstrom, P.A.; Ros, J.A.; de Angelis, G.; de France, G.; Erduran, M.N.; Erturk, S.; Gadea, A.; Gonzalez, V.; Kownacki, J.; Moszynski, M.; Nyberg, J.; Palacz, M.; Sanchis, E.; Wadsworthm, R. doi  openurl
  Title Digital pulse-timing technique for the neutron detector array NEDA Type Journal Article
  Year 2015 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 775 Issue Pages 71-76  
  Keywords Digital timing; Constant fraction discriminator; Liquid scintillator; BC501A; Neutron detector; NEDA  
  Abstract (up) A new digital pulse-timing algorithm, to be used with the future neutron detector array NEDA, has been developed and tested. The time resolution of four 5 in diameter photomultiplier tubes (XP4512, R4144, R11833-100, and ET9390-kb), coupled to a cylindrical 5 in by 5 in BC501A liquict scintillator detector was measured by employing digital sampling electronics and a constant fraction discriminator (CFD) algorithm. The zero crossing of the CM algorithm was obtained with a cubic spline interpolation, which was continuous up to the second derivative. The performance of the algorithm was studied at sampling rates of 500 MS/s and 200 MS/s. The time resolution obtained with the digital electronics was compared to the values acquired with a standard analog CFD. The result of this comparison shows that the time resolution from the analog and the digital measurements at 500 MS/s and at 200 MS/s are within 15% for all the tested photomultiplier tubes.  
  Address [Modamio, V.; Valiente-Dobon, J. J.; Triossi, A.; de Angelis, G.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: victor.modamio@lnl.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 WOS:000348040900011 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2093  
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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 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 (up) 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  
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Author PreSPEC and AGATA Collaborations (Ralet, D. et al); Domingo-Pardo, C.; Gadea, A.; Huyuk, T. doi  openurl
  Title Lifetime measurement of neutron-rich even-even molybdenum isotopes Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 95 Issue 3 Pages 034320 - 11pp  
  Keywords  
  Abstract (up) Background: In the neutron-rich A approximate to 100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A = 100 up to mass A = 108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the gamma ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a gamma-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A = 100 to A = 108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: tau = 29.7(-9.1)(+11.3) ps for the 4(+) state of Mo-108 and tau = 3.2(-0.7)(+ 0.7) ps for the 6(+) state of Mo-102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A = 100 to A = 108 with a maximum reached at N = 64. The transition probabilities decrease for Mo-108 which may be related to its well-pronounced triaxial shape indicated by the calculations.  
  Address [Ralet, D.; Cortes, M. L.; Gregor, E.; Guastalla, G.; Givechev, A.; Habermann, T.; Louchart-Henning, C.; Merchan, E.; Pietralla, N.; Reese, M.; Singh, P. P.; Stahl, C.] Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany, Email: ralet@csnsm.in2p3.fr  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000399143200002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3045  
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Author AGATA Collaboration (Louchart, C. et al); Gadea, A.; Huyuk, T. doi  openurl
  Title Collective nature of low-lying excitations in 70,72,74Zn from lifetime measurements using the AGATA spectrometer demonstrator Type Journal Article
  Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 87 Issue 5 Pages 054302 - 10pp  
  Keywords  
  Abstract (up) Background: Neutron-rich nuclei with protons in the fp shell show an onset of collectivity around N=40. Spectroscopic information is required to understand the underlying mechanism and to determine the relevant terms of the nucleon-nucleon interaction that are responsible for the evolution of the shell structure in this mass region. Methods: We report on the lifetime measurement of the first 2+ and 4+ states in 70,72,74Zn and the first 6+ state in 72Zn using the recoil distance Doppler shift method. The experiment was carried out at the INFN Laboratory of Legnaro with the AGATA demonstrator, first phase of the Advanced Gamma Tracking Array of highly segmented, high-purity germanium detectors coupled to the PRISMA magnetic spectrometer. The excited states of the nuclei of interest were populated in the deep inelastic scattering of a 76Ge beam impinging on a 238U target. Results: The maximum of collectivity along the chain of Zn isotopes is observed for 72Zn at N=42. An unexpectedly long lifetime of 20−5.2+1.8 ps was measured for the 4+ state in 74Zn. Conclusions: Our results lead to small values of the B(E2;41+→21+)/B(E2;21+→01+) ratio for 72,74Zn, suggesting a significant noncollective contribution to these excitations. These experimental results are not reproduced by state-of-the-art microscopic models and call for lifetime measurements beyond the first 2+ state in heavy zinc and nickel isotopes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1638  
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