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Author Resta-Lopez, J.
Title Nonlinear protection of beam delivery systems for multi-TeV linear colliders Type Journal Article
Year 2013 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 8 Issue Pages P11010 - 19pp
Keywords Beam Optics; Beam dynamics; Accelerator Subsystems and Technologies; Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics)
Abstract The post-linac energy collimation system of future e(+)e(-) multi-TeV linear colliders is designed to fulfil an essential function of protection of the Beam Delivery System (BDS) against miss-steered or errant beams likely generated by failure modes in the main linac. For the case of the Compact Linear Collider (CLIC), the energy collimators are required to withstand the impact of a full bunch train in case of failure. This condition makes the design of the energy collimation system especially challenging, if we take into account the need to dispose of an unprecedented transverse beam energy density per beam of the order of GJ/mm(2), when assuming the nominal CLIC beam parameters at 3 TeV centre-of-mass energy, which translates into an extremely high damage potential of uncontrolled beams. This leads to research activities involving new collimator materials and novel collimation techniques. The increase of the transverse spot size at the collimators using nonlinear magnets is a potential solution to guarantee the survival of the collimators. In this paper we present an alternative nonlinear optics based on a multipole magnet pair for energy collimation. In order to preserve an acceptable luminosity performance, we carefully study the general conditions for self-cancellation of optical aberrations between two multipoles. This nonlinear optics scheme is adapted to the requirements of the post-linac energy collimation system for the CLIC BDS, and its performance is investigated by means of beam tracking simulations. Although applied to the CLIC case, this nonlinear protection system could be adapted to other future colliders.
Address Univ Valencia, Inst Fis Corpuscular IFIC, Ctr Mixto CSIC, Inst Invest Paterna, Valencia 46071, Spain, Email: resta@ific.uv.es
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 (down) 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000329193500035 Approved no
Is ISI yes International Collaboration
Call Number IFIC @ pastor @ Serial 1697
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Author ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Jimenez Pena, J.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Pedraza Lopez, S.; Rodriguez Rodriguez, D.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period Type Journal Article
Year 2016 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 11 Issue Pages P05013 - 78pp
Keywords Beam-line instrumentation (beam position and profile monitors; beam-intensity monitors; bunch length monitors); Data analysis; Performance of High Energy Physics Detectors
Abstract This paper discusses various observations on beam-induced and cosmic-ray backgrounds in the ATLAS detector during the LHC 2012 proton-proton run. Building on published results based on 2011 data, the correlations between background and residual pressure of the beam vacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds are evaluated. New methods to monitor ghost charge with beam-gas rates are presented and observations of LHC abort gap population by ghost charge are discussed in detail. Fake jets from colliding bunches and from ghost charge are analysed with improved methods, showing that ghost charge in individual radio-frequency buckets of the LHC can be resolved. Some results of two short periods of dedicated cosmic-ray background data-taking are shown; in particular cosmic-ray muon induced fake jet rates are compared to Monte Carlo simulations and to the fake jet rates from beam background. A thorough analysis of a particular LHC fill, where abnormally high background was observed, is presented. Correlations between backgrounds and beam intensity losses in special fills with very high beta* are studied.
Address [Aad, G.; Jackson, P.; Lee, L.; Petridis, A.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia
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 (down) 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000377851700036 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2730
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Author ATLAS Tile Calorimeter System (Abdallah, J. et al); Ferrer, A.; Fiorini, L.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Ruiz-Martinez, A.; Solans, C.A.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.
Title The Laser calibration of the ATLAS Tile Calorimeter during the LHC run 1 Type Journal Article
Year 2016 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 11 Issue Pages T10005 - 29pp
Keywords Detector alignment and calibration methods (lasers, sources, particle-beams); Calorimeters; Performance of High Energy Physics Detectors
Abstract This article describes the Laser calibration system of the ATLAS hadronic Tile Calorimeter that has been used during the run 1 of the LHC. First, the stability of the system associated readout electronics is studied. It is found to be stable with variations smaller than 0.6 %. Then, the method developed to compute the calibration constants, to correct for the variations of the gain of the calorimeter photomultipliers, is described. These constants were determined with a statistical uncertainty of 0.3 % and a systematic uncertainty of 0.2 % for the central part of the calorimeter and 0.5 % for the end-caps. Finally, the detection and correction of timing mis-configuration of the Tile Calorimeter using the Laser system are also presented.
Address [Harkusha, S.; Kulchitsky, Y.; Kurochkin, Y. A.; Tsiareshka, P. V.] Natl Acad Sci Belarus, BI Stepanov Inst Phys, Minsk, Byelarus, Email: calvet@in2p3.fr
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 (down) 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000387876400005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2860
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Author BRIKEN Collaboration (Tarifeño-Saldivia, A. et al); Tain, J.L.; Domingo-Pardo, C.; Agramunt, J.; Algora, A.; Morales, A.I.; Rubio, B.; Tolosa, A.
Title Conceptual design of a hybrid neutron-gamma detector for study of beta-delayed neutrons at the RIB facility of RIKEN Type Journal Article
Year 2017 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 12 Issue Pages P04006 - 22pp
Keywords Detector modelling and simulations I (interaction of radiation with matter, interaction; of photons with matter, interaction of hadrons with matter, etc); Instrumentation for radioactive beams (fragmentation devices; fragment and isotope, separators incl. ISOL; isobar separators; ion and atom traps; weak-beam diagnostics; radioactive-beam ion sources); Neutron detectors (cold, thermal, fast neutrons)
Abstract BRIKEN is a complex detection system to be installed at the RIB-facility of the RIKEN Nishina Center. It is aimed at the detection of heavy-ion implants, β-particles, γ-rays and β-delayed neutrons. The whole detection setup involves the Advanced Implantation Detection Array (AIDA), two HPGe Clover detectors and a large set of 166 counters of 3He embedded in a high-density polyethylene matrix. This article reports on a novel methodology developed for the conceptual design and optimisation of the 3He-tubes array, aiming at the best possible performance in terms of neutron detection. The algorithm is based on a geometric representation of two selected parameters of merit, namely, average neutron detection efficiency and efficiency flatness, as a function of a reduced number of geometric variables. The response of the detection system itself, for each configuration, is obtained from a systematic MC-simulation implemented realistically in Geant4. This approach has been found to be particularly useful. On the one hand, due to the different types and large number of 3He-tubes involved and, on the other hand, due to the additional constraints introduced by the ancillary detectors for charged particles and gamma-rays. Empowered by the robustness of the algorithm, we have been able to design a versatile detection system, which can be easily re-arranged into a compact mode in order to maximize the neutron detection performance, at the cost of the gamma-ray sensitivity. In summary, we have designed a system which shows, for neutron energies up to 1(5) MeV, a rather flat and high average efficiency of 68.6%(64%) and 75.7%(71%) for the hybrid and compact modes, respectively. The performance of the BRIKEN system has been also quantified realistically by means of MC-simulations made with different neutron energy distributions.
Address [Tarifeno-Saldivia, A.] UPC, Barcelona, Spain, Email: ariel.esteban.tarifeno@upc.edu
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 (down) 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000405067800006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3209
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Author Marco-Hernandez, R.; Alves, D.; Angoletta, M.E.; Marqversen, O.; Molendijk, J.; Oponowicz, E.; Ruffieux, R.; Sanchez-Quesada, J.; Soby, L.
Title The AD and ELENA orbit, trajectory and intensity measurement systems Type Journal Article
Year 2017 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 12 Issue Pages P07024 - 24pp
Keywords Beam-line instrumentation (beam position and profile monitors; beam-intensity monitors; bunch length monitors); Data acquisition concepts; Digital electronic circuits; Digital signal processing (DSP)
Abstract This paper describes the new Antiproton Decelerator (AD) orbit measurement system and the Extra Low ENergy Antiproton ring (ELENA) orbit, trajectory and intensity measurement system. The AD machine at European Organization for Nuclear Research (CERN) is presently being used to decelerate antiprotons from 3.57 GeV/c to 100 MeV/c for matter vs anti-matter comparative studies. The ELENA machine, presently under commissioning, has been designed to provide an extra deceleration stage down to 13.7 MeV/c. The AD orbit system is based on 32 horizontal and 27 vertical electrostatic Beam Position Monitor (BPM) fitted with existing low noise front-end amplifiers while the ELENA system consists of 24 BPMs equipped with new low-noise head amplifiers. In both systems the front-end amplifiers generate a difference (delta) and a sum (sigma) signal which are sent to the digital acquisition system, placed tens of meters away from the AD or ELENA rings, where they are digitized and further processed. The beam position is calculated by dividing the difference signal by the sum signal either using directly the raw digitized data for measuring the turn-by-turn trajectory in the ELENA system or after down-mixing the signals to baseband for the orbit measurement in both machines. The digitized sigma signal will be used in the ELENA system to calculate the bunched beam intensity and the Schottky parameters with coasting beam after passing through different signal processing chain. The digital acquisition arrangement for both systems is based on the same hardware, also used in the ELENA Low Level Radio Frequency (LLRF) system, which follows the VME Switched Serial (VXS) enhancement of the Versa Module Eurocard 64x extension (VME64x) standard and includes VITA 57 standard Field Programmable Gate Array Mezzanine Card (FMC). The digital acquisition Field Programmable Gate Array (FPGA) andDigital Signal Processor (DSP) firmware sharesmany common functionalities with the LLRF system but has been tailored for this measurement application in particular. Specific control and acquisition software has been developed for these systems. Both systems are installed in AD and ELENA. The AD orbit system currently measures the orbit in AD while the ELENA system is being used in the commissioning of the ELENA ring.
Address [Marco-Hernandez, R.; Alves, D.; Angoletta, M. E.; Marqversen, O.; Molendijk, J.; Oponowicz, E.; Ruffieux, R.; Sanchez-Quesada, J.; Soby, L.] CERN, European Org Nucl Res, Beams Dept, 385 Route Meyrin, Meyrin, Switzerland, Email: Ricardo.Marco@ific.uv.es
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 (down) 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000406392600024 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3233
Permanent link to this record