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Author Bolle, E.; Casella, C.; Chesi, E.; De Leo, R.; Dissertori, G.; Fanti, V.; Gillam, J.E.; Heller, M.; Joram, C.; Lustermann, W.; Nappi, E.; Oliver, J.F.; Pauss, F.; Rafecas, M.; Rudge, A.; Ruotsalainen, U.; Schinzel, D.; Schneider, T.; Seguinot, J.; Solevi, P.; Stapnes, S.; Tuna, U.; Weilhammer, P. doi  openurl
  Title AX-PET: A novel PET concept with G-APD readout Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 695 Issue Pages 129-134  
  Keywords (down) PET; Axial geometry; Geiger-mode Avalanche Photo Diodes (G-APD); SiPM  
  Abstract The AX-PET collaboration has developed a novel concept for high resolution PET imaging to overcome some of the performance limitations of classical PET cameras, in particular the compromise between spatial resolution and sensitivity introduced by the parallax error. The detector consists of an arrangement of long LYSO scintillating crystals axially oriented around the field of view together with arrays of wave length shifter strips orthogonal to the crystals. This matrix allows a precise 3D measurement of the photon interaction point. This is valid both for photoelectric absorption at 511 key and for Compton scattering down to deposited energies of about 100 keV. Crystals and WLS strips are individually read out using Geiger-mode Avalanche Photo Diodes (G-APDs). The sensitivity of such a detector can be adjusted by changing the number of layers and the resolution is defined by the crystal and strip dimensions. Two AX-PET modules were built and fully characterized in dedicated test set-ups at CERN, with point-like Na-22 sources. Their performance in terms of energy (Renew approximate to 11.8% (FWMH) at 511 key) and spatial resolution was assessed (sigma(axial) approximate to 0.65 mm), both individually and for the two modules in coincidence. Test campaigns at ETH Zurich and at the company AAA allowed the tomographic reconstructions of more complex phantoms validating the 3D reconstruction algorithms. The concept of the AX-PET modules will be presented together with some characterization results. We describe a count rate model which allows to optimize the planing of the tomographic scans.  
  Address [Heller, M.; Joram, C.; Schneider, T.; Seguinot, J.] CERN, PH Dept, CH-1211 Geneva, Switzerland, Email: Matthieu.Heller@cern.ch  
  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:000311469900026 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1236  
Permanent link to this record
 

 
Author Casas, F.; Oteo, J.A.; Ros, J. doi  openurl
  Title Unitary transformations depending on a small parameter Type Journal Article
  Year 2012 Publication Proceedings of the Royal Society A Abbreviated Journal Proc. R. Soc. A  
  Volume 468 Issue 2139 Pages 685-700  
  Keywords (down) perturbation theory; quantum mechanics; unitary transformation; Magnus expansion  
  Abstract We formulate a unitary perturbation theory for quantum mechanics inspired by the Lie-Deprit formulation of canonical transformations. The original Hamiltonian is converted into a solvable one by a transformation obtained through a Magnus expansion. This ensures unitarity at every order in a small parameter. A comparison with the standard perturbation theory is provided. We work out the scheme up to order ten with some simple examples.  
  Address [Oteo, J. A.; Ros, J.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: rosj@uv.es  
  Corporate Author Thesis  
  Publisher Royal Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1364-5021 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000300185400005 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 893  
Permanent link to this record
 

 
Author Kowalska, M.; Naimi, S.; Agramunt, J.; Algora, A.; Beck, D.; Blank, B.; Blaum, K.; Bohm, C.; Borgmann, C.; Breitenfeldt, M.; Fraile, L.M.; George, S.; Herfurth, F.; Herlert, A.; Kreim, S.; Lunney, D.; Minaya-Ramirez, E.; Neidherr, D.; Rosenbusch, M.; Rubio, B.; Schweikhard, L.; Stanja, J.; Zuber, K. doi  openurl
  Title Trap-assisted decay spectroscopy with ISOLTRAP Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 689 Issue Pages 102-107  
  Keywords (down) Penning trap mass spectrometers; Trap-assisted decay spectroscopy; Studies at ISOL-type facilities  
  Abstract Penning traps are excellent high-precision mass spectrometers for radionuclides. The high-resolving power used for cleaning isobaric and even isomeric contaminants can be exploited to improve decay-spectroscopy studies by delivering purified samples. An apparatus allowing trap-assisted decay spectroscopy has been coupled to the ISOLTRAP mass spectrometer at ISOLDE/CERN. The results from studies with stable and radioactive ions show that the setup can be used to perform decay studies on purified short-lived nuclides and to assist mass measurements.  
  Address [Kowalska, M.; Herlert, A.] CERN, Dept Phys, CH-1211 Geneva 23, Switzerland, Email: kowalska@cern.ch  
  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:000307797500016 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1134  
Permanent link to this record
 

 
Author Pi, M.; Barranco, M.; Navarro, J.; Ancilotto, F. doi  openurl
  Title Nucleation and cavitation in parahydrogen Type Journal Article
  Year 2012 Publication Chemical Physics Abbreviated Journal Chem. Phys.  
  Volume 399 Issue Pages 213-217  
  Keywords (down) Nucleation; Cavitation; Metastable phases; Liquid parahydrogen  
  Abstract We have used a density functional approach to investigate thermal homogeneous nucleation and cavitation in parahydrogen. The effect of electrons as seeds of heterogeneous cavitation in liquid parahydrogen is also discussed within the capillary model.  
  Address [Pi, Marti; Barranco, Manuel] Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain, Email: marti@ecm.ub.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 0301-0104 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000304196100027 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1039  
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Author Sahin, E. et al; Gadea, A.; Algora, A. doi  openurl
  Title Structure of the N=50 As, Ge, Ga nuclei Type Journal Article
  Year 2012 Publication Nuclear Physics A Abbreviated Journal Nucl. Phys. A  
  Volume 893 Issue Pages 1-12  
  Keywords (down) NUCLEAR REACTIONS U-238(Se-82, Ga-81), (Se-82, Ge-82), (Se-82, As-83), E=515 MeV; measured E-gamma, I-gamma (theta), gamma gamma-coin, reaction fragments, (fragment)gamma-coin using PRISMA magnetic spectrometer, gamma after deexcitation using Ge Compton-suppressed detectors of CLARA array, thin and thick target; deduced sigma(theta), levels, J, pi; calculated levels, J, pi using shell model  
  Abstract The level structures of the N = 50 As-83, Ge-82, and Ga-81 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 gamma-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 Ni-78 (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.  
  Address [Sahin, E.; de Angelis, G.; Gadea, A.; Corradi, L.; Fioretto, E.; Gottardo, A.; Guiot, B.; Modamio, V.; Napoli, D. R.; Silvestri, R.; Stefanini, A. M.; Valiente-Dobon, J. J.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: eda.sahin@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 0375-9474 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000310091000001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1191  
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