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Author n_TOF Collaboration (Tarrio, D. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.
Title Measurement of the angular distribution of fission fragments using a PPAC assembly at CERN n_TOF Type Journal Article
Year 2014 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 743 Issue Pages 79-85
Keywords Fission; Neutron; Anisotropy; Angular distribution; Th-232; Gas detectors
Abstract A fission reaction chamber based on Parallel Plate Avalanche Counters (PPACs) was built for measuring angular distributions of fragments emitted in neutron-induced fission of actinides at the neutron beam available at the Neutron Time-Of-Flight (n_TOF) facility at CERN. The detectors and the samples were tilted 45 degrees with respect to the neutron beam direction to cover all the possible values of the emission angle of the fission fragments. The main features of this setup are discussed and results on the fission fragment angular distribution are provided for the Th-232(n,f) reaction around the fission threshold. The results are compared with the available data in the literature, demonstrating the good capabilities of this setup.
Address [Tarrio, D.; Duran, I.; Paradela, C.; Caamano, M.] Univ Santiago de Compostela, Santiago De Compostela, Spain, Email: dtarriov@gmail.com
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:000334005000011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1746
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Author AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A.
Title Response of AGATA segmented HPGe detectors to gamma rays up to 15.1 MeV Type Journal Article
Year 2013 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 705 Issue Pages 47-54
Keywords AGATA; Gamma-ray spectroscopy; Gamma-ray tracking; HPGe detectors; Pulse-shape and gamma-ray tracking algorithms; Semiconductor detector performance and simulations
Abstract The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(B-11,n gamma)C-12 at E-beam=19.1 MeV, while gamma rays between 2 and 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%.Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation caused by n-capture in Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape analysis is discussed.
Address [Crespi, F. C. L.; Avigo, R.; Camera, F.; Bottoni, S.; Bracco, A.; Ceruti, S.; Giaz, A.; Leoni, S.; Nicolini, R.; Pellegri, L.; Riboldi, S.; Vandone, V.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: fabio.crespi@mi.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:000314826000009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1329
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Author Studen, A.; Brzezinski, K.; Chesi, E.; Cindro, V.; Clinthorne, N.H.; Cochran, E.; Grosicar, B.; Grkovski, M.; Honscheid, K.; Kagan, H.; Lacasta, C.; Llosa, G.; Mikuz, M.; Stankova, V.; Weilhammer, P.; Zontar, D.
Title Silicon detectors for combined MR-PET and MR-SPECT imaging Type Journal Article
Year 2013 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 702 Issue Pages 88-90
Keywords PET; Silicon detectors; SPECT
Abstract Silicon based devices can extend PET-MR and SPECT-MR imaging to applications, where their advantages in performance outweigh benefits of high statistical counts. Silicon is in many ways an excellent detector material with numerous advantages, among others: excellent energy and spatial resolution, mature processing technology, large signal to noise ratio, relatively low price, availability, versatility and malleability. The signal in silicon is also immune to effects of magnetic field at the level normally used in MR devices. Tests in fields up to 7 T were performed in a study to determine effects of magnetic field on positron range in a silicon PET device. The curvature of positron tracks in direction perpendicular to the field's orientation shortens the distance between emission and annihilation point of the positron. The effect can be fully appreciated for a rotation of the sample for a fixed field direction, compressing range in all dimensions. A popular Ga-68 source was used showing a factor of 2 improvement in image noise compared to zero field operation. There was also a little increase in noise as the reconstructed resolution varied between 2.5 and 1.5 mm. A speculative applications can be recognized in both emission modalities, SPECT and PET. Compton camera is a subspecies of SPECT, where a silicon based scatter as a MR compatible part could inserted into the MR bore and the secondary detector could operate in less constrained environment away from the magnet. Introducing a Compton camera also relaxes requirements of the radiotracers used, extending the range of conceivable photon energies beyond 140.5 keV of the Tc-99m. In PET, one could exploit the compressed sub-millimeter range of positrons in the magnetic field. To exploit the advantage, detectors with spatial resolution commensurate to the effect must be used with silicon being an excellent candidate. Measurements performed outside of the MR achieving spatial resolution below 1 mm are reported.
Address [Studen, A.; Cindro, V.; Grosicar, B.; Grkovski, M.; Mikuz, M.; Zontar, D.] Jozef Stefan Inst, Ljubljana, Slovenia, Email: andrej.studen@ijs.si
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:000314682300026 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1331
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Author Clinthorne, N.; Brzezinski, K.; Chesi, E.; Cochran, E.; Grkovski, M.; Grosicar, B.; Honscheid, K.; Huh, S.; Kagan, H.; Lacasta, C.; Linhart, V.; Mikuz, M.; Smith, D.S.; Stankova, V.; Studen, A.; Weilhammer, P.; Zontar, D.
Title Silicon as an unconventional detector in positron emission tomography Type Journal Article
Year 2013 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 699 Issue Pages 216-220
Keywords PET; Silicon detectors; Multiresolution imaging; Magnifying PET
Abstract Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been successful in achieving similar to 5 mm FWHM spatial resolution in human studies and similar to 1 mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches including the potential for high intrinsic spatial resolution in 3D. To evaluate silicon in a variety of PET “magnifying glass” configurations, an instrument was constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors are inserted to emulate dual-ring or imaging probe geometries. Measurements using the test instrument demonstrated the capability of clearly resolving point sources of Na-22 having a 1.5 mm center-to-center spacing as well as the 1.2 mm rods of a F-18-filled resolution phantom. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration. (C) 2012 Elsevier B.V. All rights reserved.
Address [Clinthorne, Neal; Huh, Sam] Univ Michigan, Dept Radiol, Ann Arbor, MI 48109 USA, Email: nclintho@umich.edu
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:000312809200045 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1290
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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.
Title AGATA-Advanced GAmma Tracking Array Type Journal Article
Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 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