517568 SzGeCERN 20230531152333.0 oai:cds.cern.ch:517568 cerncds:FULLTEXT cerncds:CERN:FULLTEXT INIS cerncds:CERN CERN annual report 2003-3.1471 SPIRES 4739272 Inspire 563756 LHC-Project-Report-498 eng CERN-LHC-Project-Report-498 Artoos, K Study of Mechanical Disturbances in Superconducting Magnets using Piezoelectric Sensors and Quench Antenna 2003 Geneva CERN 27 Aug 2001 5 p paper Mechanical disturbances in superconducting magnets were studied by recording and characterising the signals induced in piezo-electric ceramic sensors (piezos) and accelerometers by spontaneous acoustic emission (AE) during magnet excitation. The localisation of AE sources as recorded by the piezos corresponds to the localisation obtained by another, indirect technique, the so-called Quench Antenna. Dominant acoustic wave velocities along the magnet were measured by using selected piezos as active actuators. A mechanical disturbance energy calibration is shown and a way to estimate the minimum energy needed for quenching is proposed. A statistical approach is given in order to estimate the most probable amplitude of AE. CERN EDS 20010917SLAC SIS INSP2004 Study of mechanical disturbances in superconducting magnets using piezoelectric sensors and quench antenna. , by Dezillie-B Artoos-K Siemko-A Mompo-R Tommasini, D. Mechanics and Material Engineering for Science and Experiments 2003 p 168-171 ISBN:1880132796. DT 20010811-20010816. E200342-7684513 (Compendex) SIS:2004 PR/LKR added SIS ARC-PR-2007 CLAS1 LHC-PROJECT-REPORT SzGeCERN Accelerators and Storage Rings ARTICLE CERN LHCPROJECTREPORT CERN LHC Not applicable INSPEC Superconducting-magnets INSPEC acoustic-emissions INSPEC Spontaneous-emission INSPEC actuators INSPEC Statistical-methods Dezillie, B Mompo, R Siemko, A Tommasini, D LHC EST CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-Project-Report-498 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-498 Access to fulltext document http://cds.cern.ch/record/517568/files/lhc-project-report-498.pdf Access to fulltext document http://cds.cern.ch/record/517568/files/lhc-project-report-498.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN n 200138 a2003 13 20100901 1605 CER01 20010914 518752 168-171 zhangjiajie20010811 PUBLIC 002273561CER ARTICLE ConferencePaper 0001 517567 0001 20051103 0845 CER01 20010914 002273560CER UNKNOWN DELETED 517566 SzGeCERN 20230531152333.0 oai:cds.cern.ch:517566 cerncds:FULLTEXT cerncds:CERN:FULLTEXT INIS cerncds:CERN CERCER 2273559 CERN annual report 2002-3.0595 SPIRES 4736060 Inspire 563467 LHC-Project-Report-496 eng CERN-LHC-Project-Report-496 Dahlerup-Petersen, K Energy Extraction in the CERN Large Hadron Collider a Project Overview 2001 Geneva CERN 27 Aug 2001 4 p paper In case of a resistive transition (quench), fast and reliable extraction of the magnetic energy, stored in the superconducting coils of the electromagnets of a particle collider, represents an important part of its magnet protection system. In general, the quench detectors, the quench heaters and the cold by-pass diodes across each magnet, together with the energy extraction facilities provide the required protection of the quenching superconductors against damage due to local energy dissipation. In CERN's LHC machine the energy stored in each of its eight superconducting dipole chains exceeds 1300 MJ. Following an opening of the extraction switches this energy will be absorbed in large extraction resistors located in the underground collider tunnel or adjacent galleries, during the exponential current decay. Also the sixteen, 13 kA quadrupole chains (QF, QD) and more than one hundred and fifty, 600 A circuits of the corrector magnets will be equipped with extraction systems. The extraction switch-gear is based on specially designed, mechanical high-speed DC breakers, in certain cases combined with capacitive snubber circuits for arc suppression. This paper is an overview of the complete project with emphasis on the arguments and motivation for the choice of equipment and methods. It presents the basic properties of the principal components, the operational aspects and the present state of advancement. Finally, it highlights the implications of the extraction process on other systems of the LHC collider. 7402880 20010914SLAC CERN EDS SIS INSP2002 SIS:2002 PR/LKR added SIS ARC-PR-2007 CLAS1 LHC-PROJECT-REPORT SzGeCERN Accelerators and Storage Rings ARTICLE CERN LHCPROJECTREPORT CERN LHC Not applicable INSPEC A2920L (Synchrotrons) INSPEC A2921 (Beams in particle accelerators) INSPEC B7410B (Particle beam handling and diagnostics) INSPEC B3240E (Superconducting coils and magnets) INSPEC B8370 (Switchgear) INSPEC B8360 (Power convertors and power supplies to apparatus) INSPEC NI current: 6 INSPEC accelerator-magnets INSPEC circuit-breakers INSPEC colliding-beam-accelerators INSPEC particle-beam-extraction INSPEC proton-accelerators INSPEC pulsed-power-supplies INSPEC snubbers INSPEC superconducting-coils INSPEC superconducting-magnets INSPEC switchgear INSPEC synchrotrons Erokhin, A Kazmine, B Medvedko, A S Sytchev, V V Vasilev, L B LHC CERN-Russia Collaboration CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-Project-Report-496 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-496 Access to fulltext document http://cds.cern.ch/record/517566/files/lhc-project-report-496.pdf Access to fulltext document http://cds.cern.ch/record/517566/files/lhc-project-report-496.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN BINP, Novosibirsk, Russia IHEP, Protvino, Russia n 200137 a2002 13 20100901 1605 CER01 20010914 505713 1473-6 lasvegas20010617 PUBLIC 002273559CER ARTICLE ConferencePaper 0001 517565 SzGeCERN 20230531152332.0 oai:cds.cern.ch:517565 cerncds:FULLTEXT cerncds:CERN:FULLTEXT INIS cerncds:CERN LHC-Project-Report-495 eng CERN-LHC-Project-Report-495 Aleksa, Martin AUTHOR|(CDS)2068013 #BEARD# An Improved Method using RBF Neural Networks to Speed up Optimization Algorithms 2001 Geneva CERN 27 Aug 2001 5 p paper The paper presents a method using Radial Basis Function (RBF) neural networks to speed up deterministic search algorithms used for the optimization of superconducting magnets for the LHC accelerator project at CERN. The optimization of the iron yoke of the main LHC dipoles requires a number of numerical field computations per trial solution as the field quality depends on the excitation and local iron saturation in the yoke. This results in computation times of about 30 minutes for each objective function evaluation (on DEC-Alpha 600/333). In this paper we present a method for constructing an RBF neural network for a local approximation of the objective function. The computational time required for such a construction is negligible compared to the deterministic function evaluation, and thus yields a speed-up of the overall search process. The effectiveness of this method is demonstrated by means of two- and three-parametric optimization examples. The achieved speed-up of the search routine is up to 30 %. CERN EDS 20010914SLAC SIS ARC-PR-2007 CLAS1 LHC-PROJECT-REPORT SzGeCERN Accelerators and Storage Rings CERN LHCPROJECTREPORT PREPRINT CERN LHC Not applicable Bazan, M Russenschuck, Stephan AUTHOR|(CDS)2070496 #BEARD# LHC CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-Project-Report-495 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-495 Access to fulltext document http://cds.cern.ch/record/517565/files/lhc-project-report-495.pdf Access to fulltext document http://cds.cern.ch/record/517565/files/lhc-project-report-495.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN Inst. Comput. Sci., Univ. Wroclaw n 200137 11 20100401 2001 CER01 20010914 517628 evianlesbains20010602 PUBLIC 002273558CER PREPRINT ConferencePaper 0001 517562 SzGeCERN 20230531152331.0 oai:cds.cern.ch:517562 cerncds:FULLTEXT cerncds:CERN:FULLTEXT INIS cerncds:CERN LHC-Project-Report-494 eng CERN-LHC-Project-Report-494 Aleksa, Martin AUTHOR|(CDS)2068013 #BEARD# Magnetic Field Calculations Including the Impact of Persistent Currents in Superconducting Filaments 2002 Geneva CERN 27 Aug 2001 4 p paper The magnetic field in the coils of superconducting magnets induces so-called persistent currents in the filaments. Persistent currents are bipolar screening currents that do not decay due to the lack of resistivity. The NbTi-filaments are type II superconductors and can be described by the critical state model. This paper presents an analytical hysteresis model of the filament magnetization due to persistent currents which takes into account the changing magnetic induction inside the filament. This model is combined with numerical field computation methods, taking local saturation effects in the ferromagnetic yoke into consideration. CERN EDS 20010914SLAC SIS ARC-PR-2007 CLAS1 LHC-PROJECT-REPORT SzGeCERN Accelerators and Storage Rings CERN LHCPROJECTREPORT PREPRINT CERN LHC Not applicable Russenschuck, Stephan AUTHOR|(CDS)2070496 #BEARD# Völlinger, Christine LHC CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-Project-Report-494 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-494 Access to fulltext document http://cds.cern.ch/record/517562/files/lhc-project-report-494.pdf Access to fulltext document http://cds.cern.ch/record/517562/files/lhc-project-report-494.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN n 200137 11 20100401 2001 CER01 20010914 517628 evianlesbains20010602 PUBLIC 002273551CER PREPRINT ConferencePaper 0001 525101 SzGeCERN 20230531152213.0 oai:cds.cern.ch:525101 cerncds:FULLTEXT cerncds:CERN:FULLTEXT INIS cerncds:CERN 10.1016/S0042-207X(02)00226-9 DOI CERCER 2281881 CERN annual report 2003-3.0904 SPIRES 4780345 Inspire 566815 LHC-Project-Report-518 eng CERN-LHC-Project-Report-518 Baglin, V Molecular desorption by synchrotron radiation and sticking coefficient temperatures for H$_{2}$, CH$_{4}$, CO and CO$_{2}$ Molecular Desorption by Synchrotron Radiation and Sticking Coefficient at Cryogenic Temperatures for H2, CH4, CO and CO2 Preprint title 2002 Geneva CERN 1 Nov 2001 10 p paper A cryogenic vacuum system has been used to study both the surface pumping of gases and the molecular photodesorption yield from OFE copper in the temperature range from 5 K to 300 K. The sticking coefficient on a `bare surface´ was found to increase with decreasing temperature of the substrate and below 20 K, to be in the range of a few percent for all gas species studied. The molecular photodesorption yield for the `bare surface´ was found to decrease with decreasing temperature and below 20 K, after an accumulated photon dose of 3.1 1022 photons m-1, to be in the range of 10-4 molecules photon-1 for H2 and 10-5 molecules photon-1 for the other gas species. These measured values are used to predict the evolution of the gas densities in the LHC. Implications to the LHC are discussed. CERN EDS 20011108SLAC Molecular desorption by synchrotron radiation and sticking coefficient at cryogenic temperatures for H//2, CH//4, CO and CO//2 SIS INSP2003 E200241-7138901 (Compendex) SIS:2003 PR/LKR added SIS ARC-PR-2007 CLAS1 LHC-PROJECT-REPORT SzGeCERN Accelerators and Storage Rings ARTICLE CERN LHCPROJECTREPORT CERN LHC Not applicable INSPEC Surface-treatment Collins, I R Gröbner, Oswald Grünhagel, C Jenninger, B LHC 421-428 Vacuum 67 2002 CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-Project-Report-518 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-518 Access to fulltext document http://cds.cern.ch/record/525101/files/lhc-project-report-518.pdf Access to fulltext document http://cds.cern.ch/record/525101/files/lhc-project-report-518.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN n 200145 a2003 13 20100901 1605 CER01 20011101 525747 421-428 madrid20010917 PUBLIC 0001 002281881CER ARTICLE ConferencePaper 513001 SzGeCERN 20230531161914.0 oai:cds.cern.ch:513001 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN CERCER 2268762 EDMS 316120 CERN-LHC-2001-002-CRI eng Hauviller, Claude Hygromechanical behaviour of CFRP under cyclic humidity loadings 2001 Geneva CERN 22 Jun 2001 9 p paper Report Stable lightweight structures are key issues in the design and construction of the LHC high precision particle detectors. This paper presents the results of long term measurements performed on plates manufactured in Carbon Fibre Reinforced Plastics (CFRP), material selected for these structures, subjected to cyclic humidity loadings. Test procedures are detailed; results on moisture absorption are described together with the related displacement measurements. These results indicate that cycling composites in the operating conditions of the LHC trackers does not provoke any major internal damage. CERN EDS 20010831SLAC CLAS1 LHC-CRI SzGeCERN Accelerators and Storage Rings CERN PREPRINT XX XX LHC CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-2001-002-CRI http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-2001-002 Access to fulltext document http://cds.cern.ch/record/513001/files/lhc-2001-002.pdf Access to fulltext document http://cds.cern.ch/record/513001/files/lhc-2001-002.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN n 200135 11 20100608 1158 CER01 20010803 515576 beijing20010625 PUBLIC 0001 002268762CER PREPRINT ConferencePaper 528591 SzGeCERN 20230531152045.0 oai:cds.cern.ch:528591 cerncds:FULLTEXT cerncds:CERN:FULLTEXT INIS cerncds:CERN LHC-Project-Report-520 eng CERN-LHC-Project-Report-520 Boutboul, T Critical Current Test Facilities for LHC Superconducting NbTi Cable Strands 2001 Geneva CERN 27 Nov 2001 8 p paper The Rutherford-type superconducting Cu/NbTi cables of the LHC accelerator are currently mass-produced by a few industrial firms. As a part of the acceptance tests, the critical current of superconducting multifilamentary wires is systematically measured on virgin strands to qualify the wires and on extracted strands to qualify the cables. For this purpose, four test stations are in operation at CERN to measure the critical current of strands at both 4.2 K and 1.9 K in magnetic fields in the 6-11 T range. The measurement setup and procedures of these facilities are reported in this article. The quality of the critical current test is guaranteed by supervising the SPC (Statistical Process Control) charts of a reference sample. The measurement repeatability and reproducibility of the stations are found to be excellent. Moreover, the measured critical current of a strand is found to be almost independent of the test station in which the measurement is performed. CERN EDS 20011207SLAC SIS ARC-PR-2007 CLAS1 LHC-PROJECT-REPORT SzGeCERN Accelerators and Storage Rings CERN LHCPROJECTREPORT PREPRINT CERN LHC Not applicable Charifoulline, Z Denarié, C H Oberli, L R CERN Richter, D LHC CERN Depot 4, bldg. 500-S-023 (DE4) CERN-LHC-Project-Report-520 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-520 Access to fulltext document http://cds.cern.ch/record/528591/files/lhc-project-report-520.pdf Access to fulltext document http://cds.cern.ch/record/528591/files/lhc-project-report-520.ps.gz Access to fulltext document Evelyne.Delucinge@cern.ch CERN n 200149 11 20100401 2001 CER01 20011130 580536 lyngby20010826 PUBLIC 002285494CER PREPRINT ConferencePaper 0001