1416388 20140108160738.0 CERN EDS CLAS1 SzGeCERN Accelerators and Storage Rings ARTICLE ConferencePaper Barth, K CERN Dudarev, A CERN Passardi, G CERN Ten Kate, H H J CERN CERN-ATS-2012-008 Inspire 1202405 CERN LHC ATLAS CERN ARTICLE 000720128CER evelyne.delucinge@cern.ch The ATLAS magnet system, comprising a superconducting central solenoid and three superconducting toroids, has been successfully ramped up for the first time to the nominal operational current of 20.4 kA on 4th August 2008. Since then, new cryogenic operational challenges have been raised, like the smoothing of steady-state parameters, the enhancing of transient procedures to minimize thermal shocks on the magnet cold masses, the optimization of the complex cryogenic system in order to reduce the compressors electric consumption and finally how to avoid regular clogging of the shield refrigerator by water contamination. This paper presents the heat load identification of the various cryogenic sub-systems done at 4.5 K and how one of these loads was reduced, what was gained - in term of electrical consumption - by tuning the turbines settings of the main refrigerator and finally the first consolidation of the cryogenic system implemented in order to minimize the detector downtime during LHC beam runs. n 201203 a2013 Geneva CERN 15 Jan 2012 86-93 AIP Conf. Proc. 1434 2012 9 p http://cds.cern.ch/record/1416388/files/CERN-ATS-2012-008.pdf http://cds.cern.ch/record/1416388/files/CERN-ATS-2012-008.pdf?subformat=pdfa pdfa ATS First Operational Experience and Performance Optimization of the ATLAS Magnet Cryogenic System DOI 10.1063/1.4706908 oai:cds.cern.ch:1416388 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN 2012 Delruelle, N CERN eng 13 1416377 86-93 spokane20110613 PUBLIC 1416387 20140108160737.0 CERN EDS CLAS1 SzGeCERN Accelerators and Storage Rings ARTICLE ConferencePaper Haug, F CERN Santos Silva, P CERN Kuster, M European XFEL, Hamburg Lang, P Darmstadt, Tech. Hochsch. CERN-ATS-2012-007 Inspire 1202392 Not applicable CAST CERN ARTICLE 000720127CER evelyne.delucinge@cern.ch The astroparticle physics experiment CERN Axion Solar Telescope (CAST) aims to detect hypothetical axions or axion-like particles produced in the Sun by the Primakoff process. A Large Hadron Collider (LHC) prototype superconducting dipole magnet provides a 9 T transverse magnetic field for the conversion of axions into detectable X-ray photons. These photons are detected with an X-ray telescope and a novel type of frame-store CCD detector built from radio-pure materials, installed in the optics focal plane. A novel type of cooling system has been designed and built based on krypton-filled cryogenic heat pipes, made out of oxygen-free radiopure copper, and a Stirling cryocooler as cold source. The heat pipes provide an efficient thermal coupling between the cryocooler and the CCD which is kept at stable temperatures between 150 and 230 K within an accuracy of 0.1 K. A graded-Z radiation shield, also serving as a gas cold-trap operated at 120 K, is implemented to reduce the surface contamination of the CCD window and suppress background radiation. n 201203 a2013 Geneva CERN 15 Jan 2012 1190-1197 AIP Conf. Proc. 1434 2012 9 p http://cds.cern.ch/record/1416387/files/CERN-ATS-2012-007.pdf http://cds.cern.ch/record/1416387/files/CERN-ATS-2012-007.pdf?subformat=pdfa pdfa ATS Cooling System for a Frame-Store PN-CCD Detector for Low Background Application DOI 10.1063/1.4707041 oai:cds.cern.ch:1416387 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN 2012 Pereira, H CERN eng 13 1416377 1190-1197 spokane20110613 PUBLIC 1416384 20160630003013.0 CERN EDS CLAS1 SzGeCERN Accelerators and Storage Rings ARTICLE ConferencePaper CERN-ATS-2012-006 Inspire 1202390 CERN LHC Not applicable Claudet, S CERN Alonso-Canella, I CERN Balle, C CERN Barth, K CERN Bel, J F CERN Benda, V CERN Bremer, J CERN AUTHOR|(CDS)2051088 #BEARD# Brodzinski, K CERN Casas-Cubillos, J CERN Cuccuru, G CERN Cugnet, M Serco, St. Genis-Pouilly Delikaris, D CERN Delruelle, N CERN Dufay-Chanat, L CERN Fabre, C CERN Ferlin, G CERN Fluder, C CERN Gavard, E CERN Girardot, R CERN Haug, F CERN Herblin, L CERN Junker, S CERN Klabi , T Serco, St. Genis-Pouilly Knoops, S CERN Lamboy, J P CERN Legrand, D CERN Metselaar, J CERN Park, A CERN Perin, A CERN Pezzetti, M CERN Penacoba-Fernandez, G CERN Pirotte, O CERN Rogez, E CERN Suraci, A CERN Stewart, L CERN Tavian, L J CERN Tovar-Gonzalez, A CERN Van Weelderen, R CERN Vauthier, N CERN Vullierme, B CERN Wagner, U CERN CERN ARTICLE 000720124CER evelyne.delucinge@cern.ch The Large Hadron Collider (LHC) cryogenic system comprises eight independent refrigeration and distribution systems that supply the eight 3.3 km long accelerator sectors with cryogenic refrigeration power as well as four refrigeration systems for the needs of the detectors ATLAS and CMS. In order to ensure the highest possible reliability of the installations, it is important to apply a reliability centred approach for the maintenance. Even though large scale cryogenic refrigeration exists since the mid 20th century, very little third party reliability data is available today. CERN has started to collect data with its computer aided maintenance management system (CAMMS) in 2009, when the accelerator has gone into normal operation. This paper presents the reliability observations from the operation and the maintenance side, as well as statistical data collected by the means of the CAMMS system. n 201203 a2013 Geneva CERN 15 Jan 2012 1399-1406 AIP Conf. Proc. 1434 2012 9 p http://cds.cern.ch/record/1416384/files/CERN-ATS-2012-006.pdf http://cds.cern.ch/record/1416384/files/CERN-ATS-2012-006.pdf?subformat=pdfa pdfa ATS First Assessment of Reliability Data for the LHC Accelerator and Detector Cryogenic System Components DOI 10.1063/1.4707066 oai:cds.cern.ch:1416384 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN 2012 Perinic, G CERN eng 13 1416377 1399-1406 spokane20110613 PUBLIC 1416380 20140108160737.0 CERN EDS CLAS1 SzGeCERN Accelerators and Storage Rings ARTICLE ConferencePaper Brodzinski, K CERN Pirotte, O CERN Krieger, B Bürkert GmbH Widmer, A Bürkert AG, Hünenberg CERN-ATS-2012-005 Inspire 1202391 CERN LHC Not applicable CERN ARTICLE 000720123CER evelyne.delucinge@cern.ch The Large Hadron Collider superconducting magnets are powered by more than 1400 gas cooled current leads ranging from 120 A to 13000 A. The gas flow required by the leads is controlled by solenoid proportional valves with dimensions from DN 1.8 mm to DN 10 mm. During the first months of operation, signs of premature wear were found in the active parts of the valves. This created major problems for the functioning of the current leads threatening the availability of the LHC. Following the detection of the problems, a series of measures were implemented to keep the LHC running, to launch a development program to solve the premature wear problem and to prepare for a global consolidation of the gas flow control system. This article describes first the difficulties encountered and the measures taken to ensure a continuous operation of the LHC during the first year of operation. The development of new friction free valves is then presented along with the consolidation program and the test equipment developed to validate the upgraded valves prior to their installation into the LHC. n 201203 a2013 Geneva CERN 15 Jan 2012 1345-1352 AIP Conf. Proc. 1434 2012 9 p http://cds.cern.ch/record/1416380/files/CERN-ATS-2012-005.pdf http://cds.cern.ch/record/1416380/files/CERN-ATS-2012-005.pdf?subformat=pdfa pdfa ATS Operational Experience and Consolidations for the Current Lead Control Valves of the Large Hadron Collider DOI 10.1063/1.4707060 oai:cds.cern.ch:1416380 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN 2012 Perin, A CERN eng 13 1416377 1345-1352 spokane20110613 PUBLIC 1416378 20140108160737.0 CERN EDS CLAS1 SzGeCERN Accelerators and Storage Rings ARTICLE ConferencePaper Papaphilippou, Y CERN Russenschuck, S CERN Schoerling, D CERN CERN-ATS-2012-004 Inspire 1202389 CLIC Not applicable CERN ARTICLE 000720122CER evelyne.delucinge@cern.ch The Compact Linear Collider is a future electron-positron linear collider currently under study. Before being injected into the main linear accelerating structures, both the electron and the positron beams must pass through damping rings that will drastically reduce their emittance in all three dimensions. The required emittance reduction is achieved by passing the particle beams through alternating magnetic fields in superconducting wiggler magnets that result in the emission of intense synchrotron radiation. This article describes possible cooling schemes and possible cryogenic configurations to keep the magnets at operating temperature while removing the heat generated by the synchrotron radiation. n 201203 a2013 Geneva CERN 15 Jan 2012 1425-1431 AIP Conf. Proc. 1434 2012 8 p http://cds.cern.ch/record/1416378/files/CERN-ATS-2012-004.pdf http://cds.cern.ch/record/1416378/files/CERN-ATS-2012-004.pdf?subformat=pdfa pdfa ATS Possible Cryogenic Configurations for the Superconducting Magnets of the Damping Rings of the Compact Linear Collider (CLIC) DOI 10.1063/1.4707069 oai:cds.cern.ch:1416378 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN 2012 Perin, A CERN eng 13 1416377 1425-1431 spokane20110613 PUBLIC 1416350 20180529220301.0 DOI 10.1393/ncc/i2012-11260-3 oai:cds.cern.ch:1416350 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN Inspire 1126355 CERN CDS-Invenio WebSubmit PROC Searcy, J Oregon U. Brookhaven Measurement of the top quark pair production cross section in pp collisions at $sqrt{s}$=7 TeV in $\mu$ + $\tau$ final states with ATLAS CERN LHC ATLAS PH-EP for the ATLAS collaboration 233-236 3 Nuovo Cimento C 035 2012 000720114CER INTNOTEATLASPUBL ConferencePaper ARTICLE jsearcy1@uoregon.edu ATL-PHYS-PROC-2012-009 A measurement of the cross section of top quark pair production in proton$-$proton collisions at a center-of-mass of 7 TeV at the LHC using events with an isolated $mu$ and a $ au$ lepton decaying hadronically is reported. In addition to a $mu$ and a $ au$ lepton, large missing transverse energy and two or more jets are required. At least one of the jets must be identified as originating from a $b$ quark. To identify $ au$ leptons, the analysis uses a multivariate technique based on boosted decision trees. A data sample collected by ATLAS corresponding to an integrated luminosity of 1.08 ${ m fb}^{-1}$ yields [ sigma_{tar{t}} = 142pm 21 stat pm^{20}_{16}syst pm 5 ( ext{lumi.}) ext{pb.} ] CC-BY-4.0 Preprint CERN TOP CERN INTNOTE PUBLATLAS INTNOTEATLASPUBL ARTICLE SzGeCERN Detectors and Experimental Techniques SzGeCERN Physics n 201270 13 1337259 233-236 santfeliudeguixols20110925 ATL-COM-PHYS-2012-002 4 p http://cds.cern.ch/record/1410680 Original Communication (restricted to ATLAS) http://cds.cern.ch/record/1416350/files/ATL-PHYS-PROC-2012-009.pdf Stamped by WebSubmit: 16/01/2012 2012 Geneva CERN 16 Jan 2012 eng PUBLIC 1416393 20161207222541.0 SzGeCERN Accelerators and Storage Rings ARTICLE ConferencePaper Baudouy, B IRFU, Saclay Four, A IRFU, Saclay Lentijo, F IRFU, Saclay Mapelli, A CERN Petagna, P CERN Tommasini, D CERN Geneva CERN 15 Jan 2011 CERN LHC Not applicable CERN ARTICLE 000720135CER evelyne.delucinge@cern.ch CERN-ATS-2012-010 The operation of the Large Hadron Collider superconducting magnets for current and high luminosity future applications relies on the cooling provided by helium-permeable cable insulations. These insulations take advantage of a He II micro-channels network constituting an extremely efficient path for heat extraction. In order to provide a fundamental understanding of the underlying thermal mechanisms, an experimental setup was built to investigate heat transport through single He II channels typical of the superconducting cable insulation network, where deviation from the macro-scale theory can appear. Micro-fabrication techniques were exploited to etch the channels down to a depth of ~ 16 mm. The heat transport properties were measured in static pressurized He II and analyzed in terms of the laminar and turbulent He II laws, as well as in terms of the critical heat flux between the two regions. CERN EDS CLAS1 n 201203 231-238 AIP Conf. Proc. 1434 2011 9 p http://cds.cern.ch/record/1416393/files/CERN-ATS-2012-010.pdf http://cds.cern.ch/record/1416393/files/CERN-ATS-2012-010.pdf?subformat=pdfa pdfa ATS Steady-State Heat Transfer Through Micro-Channels in Pressurized He II DOI 10.1063/1.4706925 oai:cds.cern.ch:1416393 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN Inspire 1502003 2011 Granieri, P P CERN Ecole Polytechnique, Lausanne, LPAP eng 13 1416377 spokane20110613 PUBLIC