# LHC Articles

2011-05-20
13:36
 Proton-Nucleus Collisions at the LHC: Scientific Opportunities and Requirements / Salgado, C A (ed.) (Santiago de Compostela U., IGFAE ; Santiago de Compostela U.) ; Alvarez-Muniz, J (Santiago de Compostela U., IGFAE) ; Arleo, F (Annecy, LAPTH) ; Armesto, N (Santiago de Compostela U., IGFAE) ; Botje, M (NIKHEF, Amsterdam) ; Cacciari, M (Paris, LPTHE) ; Campbell, J (Fermilab) ; Carli, C (CERN) ; Cole, B (Nevis Labs, Columbia U.) ; D'Enterria, D (CERN ; ICC, Barcelona U. ; ICREA, Barcelona) et al. Proton-nucleus (p+A) collisions have long been recognized as a crucial component of the physics programme with nuclear beams at high energies, in particular for their reference role to interpret and understand nucleus-nucleus data as well as for their potential to elucidate the partonic structure of matter at low parton fractional momenta (small-x). Here, we summarize the main motivations that make a proton-nucleus run a decisive ingredient for a successful heavy-ion programme at the Large Hadron Collider (LHC) and we present unique scientific opportunities arising from these collisions. [...] arXiv:1105.3919; CERN-PH-TH-2011-119; LHC-PROJECT-REPORT-1181.- Geneva : CERN, 2012 - 33 p. - Published in : J. Phys. G 39 (2012) 015010 Fulltext: PDF; External link: Preprint

2009-11-06
15:51
 Cold Leak Tests of LHC Beam Screens / Collomb-Patton, C (CERN) ; Cruikshank, P (CERN) ; Jenninger, B (CERN) ; Kos, N (CERN) In order to guide the high energy proton beams inside its two 27 km long vacuum rings, the Large Hadron Collider (LHC) at CERN, Geneva, makes use of superconducting technology to create the required magnetic fields. More than 4000 beam screens, cooled at 7 20 K, are inserted inside the 1.9 K beam vacuum tubes to intercept beam induced heat loads and to provide dynamic vacuum stability. [...] LHC-PROJECT-Report-1178; CERN-LHC-PROJECT-Report-1178.- Geneva : CERN, 2009 - 6 p. - Published in : Vacuum 84 (2009) 293-297 In : 12th Joint Vacuum Conference, 10th European Vacuum Conference and 7th Annual Meeting of the German Vacuum Society, Balatonalmadi, Hungary, 22 - 26 Sep 2008, pp.293-297

2009-08-19
11:20
 Measurements of heavy ion beam losses from collimation / Bruce, R (CERN) ; Assmann, Ralph Wolfgang (CERN) ; Bellodi, G (CERN) ; Bracco, C (CERN) ; Braun, H H (CERN) ; Gilardoni, S (CERN) ; Holzer, E B (CERN) ; Jowett, John M (CERN) ; Redaelli, S (CERN) ; Weiler, T (CERN) et al. The collimation efficiency for Pb ion beams in the LHC is predicted to be lower than requirements. Nuclear fragmentation and electromagnetic dissociation in the primary collimators create fragments with a wide range of Z/A ratios, which are not intercepted by the secondary collimators but lost where the dispersion has grown sufficiently large. [...] arXiv:0908.2553.- 2009 - 12 p. - Published in : Phys. Rev. Spec. Top. Accel. Beams 12 (2009) 011001 APS Published version, local copy: PDF; External link: Preprint

2009-04-21
10:04
 Cryogenic Heat Load and Refrigeration Capacity Management at the Large Hadron Collider (LHC) / Claudet, S (CERN) ; Lebrun, Ph (CERN) ; Serio, L (CERN) ; Tavian, L (CERN) ; Van Weelderen, R (CERN) ; Wagner, U (CERN) The Large Hadron Collider (LHC) is a 26.7 km high-energy proton and ion collider based on several thousand high-field superconducting magnets operating in superfluid helium below 2 K, now under commissioning at CERN. After a decade of development of the key technologies, the project was approved for construction in 1994 and the industrial procurement for the cryogenic system launched in 1997, concurrently with the completion of the R&D program. [...] LHC-PROJECT-Report-1171; CERN-LHC-PROJECT-Report-1171.- Geneva : CERN, 2009 - 7 p. Fulltext: PDF; In : 22nd International Cryogenic Engineering Conference and International Cryogenic Materials Conference 2008, Seoul, Republic of Korea, 21 - 25 Jul 2008, pp.835-840

2009-04-21
09:47
 Quality Assurance of LHC Cryogenic Instrumentation during Installation and Commissioning / Lopez Lorente, A (CERN) ; Balle, C (CERN) ; Casas-Cubillos, J (CERN) ; Fortescue, E (CERN) ; Gomes, P (CERN) ; Jeanmonod, N (CERN) ; Peñacoba, G (CERN) ; Vauthier, N (CERN) The operation and monitoring of the LHC requires a cryogenic instrumentation system of an unprecedented size (800 instrumentation crates, holding 15000 sensors and actuators), with strict constraints on temperature measurement uncertainty and radiation hardness for all sensors and actuators. This paper presents the applied procedures of quality assurance and the specific hard- & software tools used to meet and track the mentioned requirements during its lifetime (fabrication, installation, commissioning, operation and maintenance); within the given constraints of time schedule, accessibility and coordination with other teams.. LHC-PROJECT-Report-1170; CERN-LHC-PROJECT-Report-1170.- Geneva : CERN, 2009 - 7 p. Fulltext: PDF; In : 22nd International Cryogenic Engineering Conference and International Cryogenic Materials Conference 2008, Seoul, Republic of Korea, 21 - 25 Jul 2008, pp.449-454

2009-04-21
09:40
 The Control System for the Cryogenics in the LHC Tunnel / Gomes, P (CERN) ; Anastasopoulos, K (Natl. Tech. U., Athens) ; Antoniotti, F (CERN) ; Avramidou, R (Natl. Tech. U., Athens) ; Balle, Ch (CERN) ; Blanco-Viñuela, E (CERN) ; Carminati, Ch (CERN) ; Casas-Cubillos, J (CERN) ; Ciechanowski, M (AGH-UST, Cracow) ; Dragoneas, A (Natl. Tech. U., Athens) et al. The Large Hadron Collider makes extensive use of superconductors, in magnets for bending and focusing the particles, and in RF cavities for accelerating them, which are operated at 1.9 K and 4.5 K. The process automation for the cryogenic distribution around the accelerator circumference is based on 16 Programmable Logic Controllers, each running 250 control loops, 500 alarms and interlocks, and a phase sequencer. [...] LHC-PROJECT-Report-1169; CERN-LHC-PROJECT-Report-1169.- Geneva : CERN, 2009 - 7 p. Fulltext: 001 ICEC 22 - 45 - PDF; LHC-PROJECT-REPORT-1169 - PDF; In : 22nd International Cryogenic Engineering Conference and International Cryogenic Materials Conference 2008, Seoul, Republic of Korea, 21 - 25 Jul 2008, pp.45-50

2009-01-20
14:12
 An overview of the LHC Transverse Diagnostics Systems / Boccardi, A (CERN) ; Gasior, M (CERN) ; Jones, O (CERN) ; Steinhagen, R J (CERN) The unprecedented intensity and energy of the LHC proton beams will require an excellent control of the transverse beam dynamics in order to limit particle loss in the superconducting systems. Due to restricted tolerances of the machine protection system and a tight beam emittance blow-up budget only small beam excitation is allowed, making precise measurements of the transverse beam parameters very challenging. [...] LHC-PROJECT-Report-1166; CERN-BE-2009-002.- Geneva : CERN, 2009 - 5 p. Fulltext: PDF; In : 13th Beam Instrumentation Workshop, Tahoe City, CA, USA, 04 - 08 May 2008, pp.409-414

2008-10-01
04:47
 LHC Machine / Evans, Lyndon R (ed.) (CERN) ; Bryant, Philip (ed.) (CERN) 2008 - 164 p. - Published in : JINST 3 (2008) S08001 SISSA/IOP Open Access article: PDF; In : The CERN Large Hadron Collider

2008-09-05
15:04
 Impact Distribution of the Beam Losses at the LHC Collimators in Case of Magnet Failures / Gómez Alonso, A (CERN) During LHC operation, magnet failures may affect the beam optics leading to proton losses in the collimators. These losses, with about 360MJ of stored energy per beam at nominal collision operation, are potentially dangerous for the accelerator equipment. [...] LHC-PROJECT-Report-1162; CERN-LHC-PROJECT-Report-1162.- Geneva : CERN, 2008 - 4 p. Preprint: PDF; External link: Published version from JACoW In : 11th European Particle Accelerator Conference, Genoa, Italy, 23 - 27 Jun 2008, pp.WEPP068

2008-09-05
14:50
 Apertures in the LHC Beam Dump System and Beam Losses During Beam Abort / Kramer, T (CERN) ; Goddard, B (CERN) ; Gyr, M (CERN) ; Koschik, A (CERN) ; Uythoven, J (CERN) ; Weiler, T (CERN) The LHC beam dumping system (LBDS) is used to dispose accelerated protons and ions in a wide energy range from 450 GeV up to 7 TeV. An abort gap of $3 \mu$s is foreseen to avoid sweeping particles through the LHC ring aperture. [...] LHC-PROJECT-Report-1161; CERN-LHC-PROJECT-Report-1161.- Geneva : CERN, 2008 - 4 p. Fulltext: LHC-PROJECT-REPORT-1161_2 - PDF; LHC-PROJECT-REPORT-1161 - PDF; External link: Published version from JACoW In : 11th European Particle Accelerator Conference, Genoa, Italy, 23 - 27 Jun 2008, pp.WEPP064