CERN Courier September 2013 Your Solution for Helium Recovery Laboratory scale designed for your space and needs. News L H C UPGRADE Liquid Helium Plants Over 115 units shipped worldwide since 2007 US high-fi eld quadrupole magnet passes test Helium Recovery System The US LHC Accelerator Program resulting in a loss of the superconducting (LARP) has successfully tested a powerful state – that is, a quench. Over 25 units shipped worldwide since 2011 superconducting quadrupole magnet To address these challenges, LARP has that will play a key role in developing a adopted a mechanical support structure All Cryomech Liquid Helium Plants Include: new beam-focusing system for the LHC. that is based on a thick aluminum shell, This advanced system – with other major pre-tensioned at room temperature using Pulse Tube Cryocooler Technology- designed for high upgrades to be implemented over the next water-pressurized bladders and interference reliability with long mean times between maintenance decade – will allow the LHC to deliver a keys. This design concept – developed luminosity up to 10 times higher than in the at Berkeley under the US Department of Models available with liquefaction rates of 15L/Day, original design. Energy’s General Accelerator Development Dubbed HQ02a, the latest in LARP’s series programme – was compared with the 22L/Day, 40L/Day and 60L/Day of high-fi eld quadrupole magnets is wound traditional collar-based clamping system Liquefi es helium supplied by cryostat boil-off, recovery with cables of the brittle but high-performance used in Fermilab's Tevatron and all of the niobium-tin superconductor (Nb3Sn). Like all subsequent high-energy accelerators and systems or gas cylinders LHC magnets, HQ02a is designed to operate scaled up to 4 m in length in the LARP in superfl uid helium at temperatures that are long “racetrack” and long quadrupoles. Digital touch screen user interface which includes: close to absolute zero. However, it has a larger The HQ models further refi ned this Remote Monitoring & Control beam aperture than the current focusing mechanical design approach, in particular by magnets – 120 mm in diameter compared incorporating full coil alignment. Digital Level Indicator to 70 mm – and the magnetic fi eld in the The success of these tests not only superconducting coils reaches 12 T – 50% The new Nb 3Sn HQ02a quadrupole has a establishes high-performance niobium tin System Diagnostics higher than the current 8 T. The corresponding larger aperture and is designed to operate at as a powerful superconductor for use in fi eld gradient – the rate of increase of fi eld a higher magnetic fi eld than previous fi nal- accelerator magnets, it also marks a shift Less than 24 hours between start up and liquid strength over the aperture – is 170 T/m. In a focusing magnets. (Image: Berkeley Lab.) from R&D to development of the LARP helium production recent test at Fermilab, HQ02a achieved all of magnets that will be installed for the LHC its challenging objectives. currently used in the LHC and in all previous luminosity upgrade. One of LARP’s primary goals is to support superconducting magnets for particle ● LARP is a collaboration involving CERN’s plan to replace the quadrupole accelerators. Berkeley, Brookhaven, Fermilab and SLAC, Complete Helium Recovery System magnets in the interaction regions in about Modern niobium-tin can operate at a working in close partnership with CERN. It 10 years from now as part of the High higher magnetic fi eld and with a wider is now led by Giorgio Apollinari (see p57). Atmospheric Recovery Bag LHe Gas Bag @ 1 atm Extraction Luminosity LHC project (CERN Courier temperature margin than niobium-titanium. January/February 2013 p28). Not only However, it is brittle and sensitive to strain From User must the magnets produce a stronger fi eld, – critical factors where intense electrical Sommaire en français Cryostat Complete Cryomech Helium they will also require a larger temperature currents and strong magnetic fi elds Test réussi pour un aimant quadripolaire à 5 Supply He > 99.99% Recovery System Includes: margin and have to cope with the intense create enormous forces as the magnets champ élevé américain Helium radiation, which comes hand in hand with are energized. Large forces can damage Recovery the fragile conductor or cause sudden La première longue exploitation du LHC 5 Compressor Atmospheric Recovery Bag the planned increase in the rate of energetic collisions. These requirements go beyond displacements of the superconducting ALICE se rend à Stockholm et Birmingham 6 Helium Recovery Compressor the capabilities of the niobium-titanium coils, releasing energy as heat and possibly Gas Cylinders Liquid Helium Plant Conférence EPS-HEP2013 : des jours 7 (LHeP) Manifold for cylinder storage heureux pour la physique LN2 Trap The LHC’s fi rst long run Helium Purifi er T2K observe la transformation νμ → νe 8 I NTERNATIONAL J OURNAL OF H IGH -E NERGY P HYSICS From the fi rst 3.5 TeV collisions in March 2010 to the start of the avec certitude Liquid Helium Plant CERNCOURIER fi rst long shutdown in March 2013, the LHC went through three years of V OLUME 5 3 N UMBER 7 S EPTEMBER 2 0 1 3 GERDA : nouvelles limites à la double 8 Helium Purifi er improving performance. This led in 2012 to the discovery of a Higgs désintégration bêta sans neutrino boson, which made headlines around the world and brought many accolades to CERN, including the 2013 EPS-HEPP prize (p7). This issue takes a look Désintégrations baryoniques non 9 Cryomech also provides Helium Reliquefiers for use with individual cryostats. behind the scenes at what underpinned the successful operation of the LHC charmées des mésons B during this fi rst long run. With thanks to Theresa Harrison, Warwick University, Behind the scenes Surprenantes études de la multiplicité 10 at the LHC for her editorial work with the authors of these articles. Thanks also to Jesse L’incroyable légèreté de … l'électronique 13 ANNIVERSARY MAGNETS DETECTOR Karjalainen, IOP Publishing, for his work on the design of what will be his last The discovery of Success for neutral currents US high-fi eld DEVELOPMENT 40 years ago quadrupole A look at the p53 p5 AIDA project p49 issue of CERN Courier as he heads for pastures new after six years. Les sursauts radio rapides signalent-ils la 14 formation des trous noirs ? 113 Falso Drive, Syracuse, New York, 13211 USA • Ph. 315-455-2555 Fax. 315-455-2544 www.cryomech.com [email protected] 5 Untitled-4 1 19/07/2013 14:46 CERNCOURIER www. V OLUME 5 3 N UMBER 7 S EPTEMBER 2 0 1 3 CERN Courier September 2013 CERN Courier September 2013 News News C ONFERENCE ALICE goes to Stockholm EPS-HEP2013: these are good and Birmingham times for physics Stockholm, with its many stretches of water, islands The ALICE collaboration had and old town, provided an a signifi cant presence at two ALICE |Δη| > 0.8 (near side only) attractive setting for the 2013 p-Pb √s = 5.02 TeV recent major conferences, the NN International Europhysics 0.2 (0–20%) – (60–100%) 2013 European Physical Society Conference on High-Energy Physics, Conference on High-Energy h π EPS-HEP2013 on 18–24 July. Hosted by Physics (EPSHEP 2013), in Stockholm K p the KTH (Royal Institute of Technology) (p7), and the 14th Topical Conference on and Stockholm University, the conference Strangeness in Heavy Flavour Production 0.1 centres on a busy programme of parallel and (2PC, sub) 2 in Heavy-Ion Collisions – Strangeness v plenary sessions. in Quark Matter 2013 (SQM2013) – that Like particle physics itself, EPS-HEP Left: Paris Sphicas, chair of the international organizing committee, centre, with the took place on 22–27 July at Birmingham has a global reach, with people attending winners of the 2013 EPS-HEPP prize, left to right, Peter Jenni, Tejinder Virdee, Dave University in the UK. from Asia and the Americas, as well as Charlton and Joe Incandela. (Image credit: Abha Eli Phoboo.) Right: François Englert and The many contributed talks and plenary 0 from Europe. This year there were some Peter Higgs, on either side of CERN’s director-general, Rolf Heuer, at the press conference. 1 presentations, in particular at SQM2013, 0 2 3 4 750 participants, including many young (Image credit: Terry Pritchard.) p (GeV/c) highlighted new results from the proton–lead T people who presented results in both (pPb) data recorded in early 2013. While this The remaining second fourier coeffi cient, parallel and poster sessions. As many as on ultrarelativistic heavy ions, which also developments in the context of the update of run was initially intended to provide control v2, of the Δφ two particle correlations at 440 speakers and more than 100 presenters featured presentions of measurements the European Strategy for Particle Physics. data sets, several unexpected, and currently large Δη as a function of p T for π (red of posters brought news from a host of from the Relativistic Heavy-Ion Collider An important highlight of the conference unexplained, results have been observed. triangles) K (green stars), p (blue cirlces), experiments around the world, ranging from at Brookhaven. First results from the was the awarding of the European Physical Most intriguingly, both the spectra of and charged particles (black squares) in those at particle accelerators and colliders to proton–lead run at the LHC are yielding Society High Energy and Particle Physics identifi ed particles and charged-hadron 0–20% centrality pPb collisions after others deep underground and in space. surprises, including some intriguing Prize to the ATLAS and CMS collaborations correlations in high-multiplicity pPb events subtraction of the correlations measured in Coming just one year after the similarities with fi ndings in lead–lead “for the discovery of a Higgs boson, as reveal signals suggestive of collective fl ow, the 60–10% centrality class.