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Author Scandale, W. et al; Lari, L.
Title Optimization of the crystal assisted collimation of the SPS beam Type Journal Article
Year 2013 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 726 Issue 1-3 Pages 182-186
Keywords Accelerator; Beam collimation; Crystal; Channeling
Abstract The possibility for optimization of crystal assisted collimation has been studied at the CERN SPS for stored beams of protons and Pb ions with 270 GeV/c per unit charge. A bent silicon crystal used as a primary collimator deflects halo particles in the channeling regime, directing them into a tungsten absorber. In channeling conditions a strong reduction of off-momentum particle numbers produced in the crystal and absorber, which form collimation leakage, has been observed in the first high dispersion (HD) area downstream. The present study shows that the collimation leakage is minimal for some values of the absorber offset relative to the crystal. The optimal offset value is larger for Pb ions because of their considerably larger ionization losses in the crystal, which cause large increases of particle betatron oscillation amplitudes. The optimal absorber offset allows obtaining maximal efficiency of crystal-assisted collimation.
Address [Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Schoofs, P.; Smirnov, G.] CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland, Email: alexander.taratin@cern.ch
Corporate Author Thesis
Publisher (up) 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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000326482200020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1694
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Author Lobo, F.S.N.; Martinez-Asencio, J.; Olmo, G.J.; Rubiera-Garcia, D.
Title Planck scale physics and topology change through an exactly solvable model Type Journal Article
Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 731 Issue Pages 163-167
Keywords Modified gravity; Palatini formalism; Planck scale physics; Dynamical Vaidya solutions; Topology change
Abstract We consider the collapse of a charged radiation fluid in a Planck-suppressed quadratic extension of General Relativity (GR) formulated A la Palatini. We obtain exact analytical solutions that extend the charged Vaidya-type solution of GR, which allows to explore in detail new physics at the Planck scale. Starting from Minkowski space, we find that the collapsing fluid generates wormholes supported by the electric field. We discuss the relevance of our findings in relation to the quantum foam structure of space-time and the meaning of curvature divergences in this theory.
Address [Lobo, Francisco S. N.] Univ Lisbon, Ctr Astron & Astrofis, P-1749016 Lisbon, Portugal, Email: flobo@cii.fc.ul.pt;
Corporate Author Thesis
Publisher (up) 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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000334094500028 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1757
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Author Goasduff, A.; Valiente-Dobon, J.J.; Lunardi, S.; Haas, F.; Gadea, A.; de Angelis, G.; Bazzacco, D.; Courtin, S.; Farnea, E.; Gottardo, A.; Michelagnoli, C.; Mengoni, D.; Napoli, D.R.; Recchia, F.; Sahin, E.; Ur, C.A.
Title Counting rate measurements for lifetime experiments using the RDDS method with the new generation gamma-ray array AGATA Type Journal Article
Year 2014 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 758 Issue Pages 1-3
Keywords Lifetime measurement; gamma spectroscopy; Counting rate
Abstract The differential Recoil Distance Doppler Shift (RDDS) method after multinucleon transfer (MNT) reactions to measure lifetimes of excited states in neutron-rich nuclei requires the use of a thick energy degrader for the recoiling ejectiles that are then detected in a spectrometer. This type of measurements greatly benefits from the use of the new generation segmented gamma-ray detectors, such as the AGATA demonstrator which offers unprecedented energy and angular resolutions. In order to make an optimized choice of the material and the thickness of the degrader for lifetime measurements using the RODS method after MNT, an experiment has been performed with the AGATA demonstrator. Counting rate measurements for different degraders are presented.
Address [Goasduff, A.; Haas, F.; Courtin, S.] Univ Strasbourg, IPHC, F-67037 Strasbourg, France, Email: Alain.Goasduff@csnsm.in2p3.fr
Corporate Author Thesis
Publisher (up) 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:000338348900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1829
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Author Mengoni, D.; Duenas, J.A.; Assie, M.; Boiano, C.; John, P.R.; Aliaga, R.J.; Beaumel, D.; Capra, S.; Gadea, A.; Gonzales, V.; Gottardo, A.; Grassi, L.; Herrero-Bosch, V.; Houdy, T.; Martel, I.; Parkar, V.V.; Perez-Vidal, R.M.; Pullia, A.; Sanchis, E.; Triossi, A.; Valiente-Dobon, J.J.
Title Digital pulse-shape analysis with a TRACE early silicon prototype Type Journal Article
Year 2014 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 764 Issue Pages 241-246
Keywords Silicon detector; Light-charged particles; Digital pulse shape analysis; Particle identification; Gamma-ray spectroscopy
Abstract A highly segmented silicon-pad detector prototype has been tested to explore the performance of the digital pulse shape analysis in the discrimination of the particles reaching the silicon detector. For the first time a 200 tun thin silicon detector, grown using an ordinary floating zone technique, has been shown to exhibit a level discrimination thanks to the fine segmentation. Light-charged particles down to few MeV have been separated, including their punch-through. A coaxial HPGe detector in time coincidence has further confirmed the quality of the particle discrimination.
Address [Mengoni, D.; John, P. R.; Grassi, L.] Univ Padua, Dipartimento Fis & Astron, I-35131 Padua, Italy
Corporate Author Thesis
Publisher (up) 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:000341987000030 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1929
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Author Scandale, W et al; Lari, L.
Title Deflection of high energy protons by multiple volume reflections in a modified multi-strip silicon deflector Type Journal Article
Year 2014 Publication Nuclear Instruments & Methods in Physics Research B Abbreviated Journal Nucl. Instrum. Methods Phys. Res. B
Volume 338 Issue Pages 108-111
Keywords Accelerator; Beam collimation; Crystal; Channeling; Volume reflection
Abstract The effect of multiple volume reflections in one crystal was observed in each of several bent silicon strips for 400 GeV/c protons. This considerably increased the particle deflections. Some particles were also deflected due to channeling in one of the subsequent strips. As a result, the incident beam was strongly spread because of opposite directions of the deflections. A modified multi-strip deflector produced by periodic grooves on the surface of a thick silicon plate was used for these measurements. This technique provides perfect mutual alignment between crystal strips. Such multi-strip deflector may be effective for collider beam halo collimation and a study is planned at the CERN SPS circulating beam.
Address [Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Schoofs, P.; Smirnov, G.] CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland
Corporate Author Thesis
Publisher (up) 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 0168-583x ISBN Medium
Area Expedition Conference
Notes WOS:000343390400016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1974
Permanent link to this record