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Author AGATA Collaboration (Soderstrom, P.A. et al); Gadea, A. doi  openurl
  Title (up) 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 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 Collaboration (Kaya, L. et al); Gadea, A. doi  openurl
  Title (up) Isomer spectroscopy in Ba-133 and high-spin structure of Ba-134 Type Journal Article
  Year 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 100 Issue 2 Pages 024323 - 18pp  
  Keywords  
  Abstract The transitional nuclei Ba-134 and Ba-133 are investigated after multinucleon transfer employing the high-resolution Advanced GAmma Tracking Array coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and after fusion-evaporation reaction at the FN tandem accelerator of the University of Cologne, Germany. The J(pi) = 19/2(+) state at 1942 keV in Ba-133 is identified as an isomer with a half-life of 66.6(20) ns corresponding to a B(E1) value of 7.7(4) x 10(-6) e(2) fm(2) for the J(pi) = 19/2(+) to J(pi) = 19/2(-) transition. The level scheme of Ba-134 above the J(pi) = 10(+) isomer is extended to approximately 6 MeV. A pronounced backbending is observed at h omega = 0.38 MeV along the positive-parity yrast band. The results are compared to the high-spin systematics of the Z = 56 isotopes. Large-scale shell-model calculations employing the GCN50:82, SN100PN, SNV, PQM130, Realistic SM, and EPQQM interactions reproduce the experimental findings and elucidate the structure of the high-spin states. The shell-model calculations employing the GCN50:82 and PQM130 interactions reproduce alignment properties and provide detailed insight into the microscopic origin of this phenomenon in transitional Ba-134.  
  Address [Kaya, L.; Vogt, A.; Reiter, P.; Arnswald, K.; Birkenbach, B.; Blazhev, A.; Droste, M.; Eberth, J.; Esmaylzadeh, A.; Fransen, C.; Hess, H.; Hirsch, R.; Jolie, J.; Karayonchev, V; Kornwebel, L.; Lewandowski, L.; Mueller-Gatermann, C.; Regis, J-M; Saed-Samii, N.; Schomacker, K.; Seidlitz, M.; Siebeck, B.; Wolf, K.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: levent.kaya@ikp.uni-koeln.de  
  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:000480688200004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4106  
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Author AGATA Collaboration (Alexander, T. et al); Gadea, A. doi  openurl
  Title (up) Isomeric ratios in Hg-206 Type Journal Article
  Year 2015 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B  
  Volume 46 Issue 3 Pages 601-605  
  Keywords  
  Abstract Hg-206 was populated in the fragmentation of an E/A = 1 GeV Pb-208 beam at GSI. It was part of a campaign to study nuclei around Pb-208 via relativistic Coulomb excitation. The observation of the known isomeric states confirmed the identification of the fragmentation products. The isomeric decays were also used to prove that the correlations between beam identification detectors and the AGATA gamma-ray tracking array worked properly and that the tracking efficiency was independent of the time relative to the prompt flash.  
  Address [Alexander, T.; Podolyak, Zs.; Bowry, M.; Carroll, R.; Gelletly, W.; Patel, Z.; Regan, P. H.; Walker, P. M.; Wilson, E.; Wood, R.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England  
  Corporate Author Thesis  
  Publisher Wydawnictwo Uniwersytetu Jagiellonskiego Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0587-4254 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000353565500038 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2219  
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Author AGATA Collaboration (Vogt, A. et al); Gadea, A. doi  openurl
  Title (up) Isomers and high-spin structures in the N=81 isotones Xe-135 and Ba-137 Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 95 Issue 2 Pages 024316 - 17pp  
  Keywords  
  Abstract The high-spin structures and isomers of the N = 81 isotones Xe-135 and Ba-137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in Xe-136+ U-238 and (ii) Xe-136+ Pb-208 MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii) in the Xe-136+ Pt-198 MNT reaction employing the gamma-ray array GAMMASPHERE in combination with the gas-detector array CHICO, and (iv) via a B-11+ Te-130 fusion-evaporation reaction with the HORUS gamma-ray array at the University of Cologne. The high-spin level schemes of Xe-135 and Ba-137 are considerably extended to higher energies. The 2058-keV (19/2(-)) state in Xe-135 is identified as an isomer, closing a gap in the systematics along the N = 81 isotones. Its half-life is measured to be 9.0(9) ns, corresponding to a reduced transition probability of B(E2,19/2(-) -> 15/2(-)) = 0.52(6) W.u. The experimentally deduced reduced transition probabilities of the isomeric states are compared to shell-model predictions. Latest shell-model calculations reproduce the experimental findings generally well and provide guidance to the interpretation of the new levels.  
  Address [Vogt, A.; Birkenbach, B.; Reiter, P.; Blazhev, A.; Arnswald, K.; Eberth, J.; Fu, B.; Geibel, K.; Hess, H.; Hirsch, R.; Jolie, J.; Kaya, L.; Lewandowski, L.; Liang, X.; Mueller-Gatermann, C.; Queiser, M.; Radeck, F.; Rosiak, D.; Saed-Samii, N.; Schneiders, D.; Seidlitz, M.; Siebeck, B.; Steinbach, T.; Wiens, A.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: andreas.vogt@ikp.uni-koeln.de  
  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:000393944100004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2967  
Permanent link to this record
 

 
Author AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A. doi  openurl
  Title (up) Isospin Character of Low-Lying Pygmy Dipole States in Pb-208 via Inelastic Scattering of O-17 Ions Type Journal Article
  Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 113 Issue 1 Pages 012501 - 5pp  
  Keywords  
  Abstract The properties of pygmy dipole states in Pb-208 were investigated using the Pb-208(O-17, O-17'gamma) reaction at 340 MeV and measuring the gamma decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted gamma rays and of the scattered particles were measured. The results are compared with (gamma, gamma') and (p, p') data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the 2(+) and 3(-) states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the 1(-) excited states from 4 to 8 MeV.  
  Address [Crespi, F. C. L.; Bracco, A.; Nicolini, R.; Pellegri, L.; Leoni, S.; Avigo, R.; Bottoni, S.; Camera, F.; Ceruti, S.; Morales, A. I.; Vandone, V.; Pullia, A.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: angela.bracco@mi.infn.it  
  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 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000338665200009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1848  
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