|   | 
Details
   web
Records
Author Belver-Aguilar, C.; Faus-Golfe, A.; Toral, F.; Barnes, M.J.
Title Stripline design for the extraction kicker of Compact Linear Collider damping rings Type Journal Article
Year 2014 Publication Physical Review Special Topics-Accelerators And Beams Abbreviated Journal (up) Phys. Rev. Spec. Top.-Accel. Beams
Volume 17 Issue 7 Pages 071003 - 14pp
Keywords
Abstract In the framework of the design study of future linear colliders, the Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal center-of-mass energy of 3 TeV. To achieve the luminosity requirements, predamping rings ( PDRs) and damping rings ( DRs) are required: they reduce the beam emittance before the beam is accelerated in the main linac. Several kicker systems are needed to inject and extract the beam from the PDRs and DRs. In order to achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. In this paper, we present the complete design of the striplines for the DR extraction kicker, since it is the most challenging from the field homogeneity point of view. The excellent field homogeneity required, as well as a good transmission of the high voltage pulse through the electrodes, has been achieved by choosing a novel electrode shape. With this new geometry, it has been possible to benefit from all the advantages that the most common shapes introduce separately. Furthermore, a detailed study of the different operating modes of a stripline kicker allowed the beam coupling impedance to be reduced at low frequencies: this cannot be achieved by tapering the electrodes. The optimum design of the striplines and their components has been based on studies of impedance matching, field homogeneity, power transmission, beam coupling impedance, and manufacturing tolerances. Finally, new ideas for further improvement of the performance of future striplines are reported.
Address [Belver-Aguilar, C.; Faus-Golfe, A.] Inst Fis Corpuscular, Paterna 46980, Spain
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 1098-4402 ISBN Medium
Area Expedition Conference
Notes WOS:000341249400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1898
Permanent link to this record
 

 
Author Bruce, R. et al; Lari, L.
Title Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider Type Journal Article
Year 2014 Publication Physical Review Special Topics-Accelerators and Beams Abbreviated Journal (up) Phys. Rev. Spec. Top.-Accel. Beams
Volume 17 Issue 8 Pages 081004 - 16pp
Keywords
Abstract The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.
Address [Bruce, R.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.] CERN, CH-1211 Geneva, Switzerland, Email: roderik.bruce@cern.ch
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 1098-4402 ISBN Medium
Area Expedition Conference
Notes WOS:000341259800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1905
Permanent link to this record
 

 
Author Krzysiek, M. et al; Gadea, A.; Huyuk, T.; Barrientos, D.
Title Study of the soft dipole modes in Ce-140 via inelastic scattering of O-17 Type Journal Article
Year 2014 Publication Physica Scripta Abbreviated Journal (up) Phys. Scr.
Volume 89 Issue 5 Pages 054016 - 6pp
Keywords pygmy dipole resonances; inelastic scattering; AGATA detector; gamma spectroscopy
Abstract The main aim of this study was a deeper understanding of the nuclear structure properties of the soft dipole modes in Ce-140, excited via inelastic scattering of weakly bound O-17 projectiles. An important aim was to investigate the 'splitting' of the PDR into two parts: a low-energy isoscalar component dominated by neutron-skin oscillations and a higher-energy component lying on the tail of the giant dipole resonance of a rather isovector character. This was already observed for this nucleus, investigated in (alpha, alpha') and (gamma,gamma') experiments. The experiment was performed at Laboratori Nazionali di Legnaro, Italy. Inelastic scattering of O-17 ion beam at 20 MeV A(-1) was used to excite the resonance modes in the Ce-140 target. Gamma-rays were registered by five triple clusters of AGATA-Demonstrator and nine large volume scintillators (LaBr3). The scattered O-17 ions were identified by two Delta E – E Si telescopes of the TRACE array mounted inside the scattering chamber. The telescopes consisted of two segmented Si-pad detectors, each of 60 pixels. Very preliminary data have shown a strong domination of the E1 transitions in the 'pygmy' region with a character more similar to the one obtained in alpha scattering experiment.
Address [Krzysiek, M.; Kmiecik, M.; Maj, A.; Bednarczyk, P.; Ciemala, M.; Fornal, B.; Grebosz, J.; Mazurek, K.; Meczynski, W.; Zieblinski, M.] Polish Acad Sci, H Niewodniczanski Inst Nucl Phys, Krakow, Poland, Email: mateusz.krzysiek@ifj.edu.pl
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000335785300016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1790
Permanent link to this record
 

 
Author Tarifeño-Saldivia, A.; Soto, L.
Title Effects of gas chamber geometry and gas flow on the neutron production in a fast plasma focus neutron source Type Journal Article
Year 2014 Publication Plasma Physics and Controlled Fusion Abbreviated Journal (up) Plasma Phys. Control. Fusion
Volume 56 Issue 12 Pages 125013 - 5pp
Keywords pulsed neutron source; repetitive plasma focus; neutron yield measurement; fast plasma focus
Abstract This work reports that gas chamber geometry and gas flow management substantially affect the neutron production of a repetitive fast plasma focus. The gas flow rate is the most sensitive parameter. An appropriate design of the gas chamber combined with a suitable flow-rate management can lead to improvements in the neutron production of one order of magnitude working in a fast repetitive mode.
Address [Tarifeno-Saldivia, Ariel; Soto, Leopoldo] Comis Chilena Energia Nucl CCHEN, Santiago, Chile, Email: atarisal@gmail.com;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0741-3335 ISBN Medium
Area Expedition Conference
Notes WOS:000346926300024 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2070
Permanent link to this record
 

 
Author Pich, A.
Title Precision tau physics Type Journal Article
Year 2014 Publication Progress in Particle and Nuclear Physics Abbreviated Journal (up) Prog. Part. Nucl. Phys.
Volume 75 Issue Pages 41-85
Keywords Electroweak and strong interactions; Leptons; Standard Model
Abstract Precise measurements of the lepton properties provide stringent tests of the Standard Model and accurate determinations of its parameters. We overview the present status of tau physics, highlighting the most recent developments, and discuss the prospects for future improvements. The leptonic decays of the tau lepton probe the structure of the weak currents and the universality of their couplings to the W boson. The universality of the leptonic Z couplings has also been tested through Z -> l(+)l(-) decays. The hadronic tau decay modes constitute an ideal tool for studying low-energy effects of the strong interaction in very clean conditions. Accurate determinations of the QCD coupling and the Cabibbo mixing V-us have been obtained with tau data. The large mass of the tau opens the possibility to study many kinematically-allowed exclusive decay modes and extract relevant dynamical information. Violations of flavour and CP conservation laws can also be searched for with tau decays. Related subjects such as μdecays, the electron and muon anomalous magnetic moments, neutrino mixing and B-meson decays into tau leptons are briefly covered. Being one the fermions most strongly coupled to the scalar sector, the tau lepton is playing now a very important role at the LHC as a tool to test the Higgs properties and search for new physics at higher scales.
Address Univ Valencia, CSIC, Dept Fis Teor, IFIC, E-46071 Valencia, Spain, Email: pich@ific.uv.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 0146-6410 ISBN Medium
Area Expedition Conference
Notes WOS:000332350600002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1716
Permanent link to this record