P. Fessia

European Organization for Nuclear Research

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E. Todesco

European Organization for Nuclear Research

M. Bajko

European Organization for Nuclear Research

G. de Rijk

European Organization for Nuclear Research

L. Rossi

Istituto Nazionale di Fisica Nucleare, Laboratori Acceleratori e Superconduttività Applicata

F. Savary

European Organization for Nuclear Research

J. C. Pérez

European Organization for Nuclear Research

M. Modena

European Organization for Nuclear Research

D. Tommasini

European Organization for Nuclear Research

P. Ferracin

Lawrence Berkeley National Laboratory

L. Bottura

European Organization for Nuclear Research

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European Organization for Nuclear Research

599

Fermi National Accelerator Laboratory

Lawrence Berkeley National Laboratory

Brookhaven National Laboratory

Istituto Nazionale di Fisica Nucleare

Commissariat à l'Énergie Atomique et aux Énergies Alternatives

Centre National de la Recherche Scientifique

Institut de Recherche sur les Lois Fondamentales de l'Univers

École Polytechnique Fédérale de Lausanne

Cockcroft Institute

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High Luminosity Large Hadron Collider HL-LHC

G. Apollinari Isabel Bejar Alonso O. Brüning P. Fessia M. Lamont

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a newenergy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists work-ing in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. Tosustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase itsinstantaneous luminosity (rate of collisions) by a factor of five beyond the original design value and the integratedluminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely opti-mised machine so this upgrade must be carefully conceived and will require about ten years to implement. Thenew configuration, known as High Luminosity LHC (HL-LHC), relies on a number of key innovations that pushaccelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting mag-nets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology andphysical processes for beam collimation and 100 metre-long high-power superconducting links with negligibleenergy dissipation. The present document describes the technologies and components that will be used to realisethe project and is intended to serve as the basis for the detailed engineering design of HL-LHC.

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Overview and status of the Next European Dipole Joint Research Activity

Superconductor Science and Technology (2006)

A. Devred Bertrand Baudouy D.E. Baynham T. Boutboul Simon Canfer

The Next European Dipole (NED) Joint Research Activity was launched on 1 January 2004 to promote the development of high-performance Nb3Sn conductors in collaboration with European industry (aiming at a non-copper critical current density of 1500 A mm−2 at 4.2 K and 15 T) and to assess the suitability of Nb3Sn technology to the next generation of accelerator magnets (aiming at an aperture of 88 mm and a conductor peak field of ∼15 T). It is part of the Coordinated Accelerator Research in Europe (CARE) project, which involves eight collaborators, and is half-funded by the European Union. After briefly recalling the Activity organization, we report the main progress achieved over the last year, which includes: the manufacturing of a double-bath He II cryostat for heat transfer measurements through Nb3Sn conductor insulation, detailed quench computations for various NED-like magnet configurations, the award of two industrial subcontracts for Nb3Sn conductor development, the first results of a cross-calibration programme of test facilities for Nb3Sn wire characterization, detailed investigations of the mechanical properties of heavily cold-drawn Cu/Nb/Sn composite wires, and the preliminary assessment of a new insulation system based on polyimide-sized glass fibre tapes. Last, we briefly review the efforts of an ongoing Working Group on magnet design and optimization.

Cryostat

Dipole magnet

10.1088/0953-2048/19/3/010

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Design, manufacturing status, first results of the LHC main dipole final prototypes and steps towards series manufacture

IEEE Transactions on Applied Superconductivity (2000)

Kurt Artoos L. Bottura P. Fessia M. Bajko M. Modena

This paper reports about the program of six LHC superconducting main dipole final prototypes and the steps towards series manufacture. The above program, launched in summer 1998, relies on collared coils manufactured by industry and cold masses assembled at the CERN Magnet Assembly Facility. Following design, stability and robustness studies, the magnet design for series manufacture features a "6-block" coil and austenitic steel collars. A general description of the magnet with its main components is given and the main working parameters and the most important manufacturing features are presented. Results of mechanical and magnetic measurements are given as well as the performances of the first prototype. A comparison with results from the previous generation of dipole magnet models and prototypes is also made. Finally an outlook towards series manufacture is given.

Robustness

Dipole magnet

10.1109/77.828185

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LHC Superconducting Dipole Production Follow-up: Results of Audit on QA Aspects in Industry

IEEE Transactions on Applied Superconductivity (2006)

M. Modena M. Bajko M. Cornelis P. Fessia P. Liénard

The manufacturing of the 1232 Superconducting Main Dipoles for LHC is under way at three European Contractors: Alstom-Jeumont (Consortium), Ansaldo Superconduttori Genova and Babcock Noell Nuclear. The manufacturing is proceeding in a very satisfactory way and in March 2005 the mid production was achieved. To intercept eventually “weak points” of the production process still present and in order to make a check of the Quality Assurance and Control in place for the series production, an Audit action was launched by CERN during summer-fall 2004. Aspects like: completion of Production and Quality Assurance documentation, structure of QC Teams, traceability, calibration and maintenance for tooling, incoming components inspections, were checked during a total of seven visits at the five different production sites. The results of the Audit in terms of analysis of “systematic” and “random” problems encountered as well as corrective actions requested are presented.

Traceability

10.1109/tasc.2006.870496

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PERFORMANCE OF LHC MAIN DIPOLES FOR BEAM OPERATION

G. de Rijk M. Bajko L. Bottura Marco Buzio V. Chohan

At present about 90 % of the main dipoles for the LHC have been manufactured and one of the three cold mass assemblers has already completed the production. 85 % of the 1232 dipoles needed for the tunnel have been tested and accepted. In this paper we mainly deal with the performance results: the quench behaviour, the magnetic field quality, the electrical integrity quality and the geometry features will be summarized. PRODUCTION AND QUALITY Production has now reached over 1100 Cold Masses of the 1232 CMs to be installed and is expected to be completed by the end of October 2006 [1]. Cold tests on the remaining ~ 200 CMs are expected to finish by the end of 2006. During CM production the quality at the Cold Mass Assembler factories is assured by an extensive plan, which is an integral part of the technical specification. Early detection of faults during the assembly procedure is provided by a magnetic field measurement at room temperature. A total of 18 cases have been found [2], with 4 faults in the assembly, and 14 non-conform components. Magnetic measurements at room temperature have also been used to locate the position of electrical shorts for 18 cases [3]. Among them, 12 occurred in the inner layer and 4 on the outer one. In all cases the shorts were in the coil heads. After delivery to CERN, tests and measurements in operating (cryogenic) conditions are done to qualify the magnets. These tests are on the geometry, electrical integrity, quench behaviour and magnetic field quality.

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HiLumi Photo Contest 2018: The Beauty of Engineering

Adrià Gallifa Terricabras Joshua Herrera Andrea Musso Sławosz Uznański G. Stancari

Beauty

CONTEST

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CONSOLIDATION OF THE LHC SUPERCONDUCTING CIRCUITS: A MAJOR STEP TOWARDS 14 TeV COLLISIONS

Conf. Proc. (2012)

F. Bertinelli F. Bordry P. Fessia R. Ostojić A. Perin

Following the incident in one of the main dipole circuits of the Large Hadron Collider (LHC) in September 2008, a detailed analysis of all magnet circuits has been performed by a dedicated task force. This analysis has revealed critical issues in the design of the 13 kA splices between the superconducting dipole and quadrupole magnets. These splices have to be consolidated before increasing the beam energy above 4 TeV and operating the LHC at 6.5-7 TeV per beam. The design of the consolidated 13 kA splices is complete and has been reviewed by an international committee of experts. Also, all other types of superconducting circuits have been thoroughly screened for potential safety issues and several important recommendations were established. They were critically assessed and the resulting actions are presented. In addition to the work on the 13 kA splices, other interventions will be performed during the first long shut-down of the LHC to consolidate globally all superconducting circuits. The associated quality control has been defined. Schedule constraints, repair production rate, available space and resources are presented as well.

Superconducting Super Collider

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Statistical studies of the robustness of the LHC main dipole mechanical structure

IEEE Transactions on Applied Superconductivity (2000)

M. Bajko P. Fessia D. Perini

This paper describes two methods used to study the effect of the tolerances of the components on the structure of the LHC main dipole. The first method, called semi-statistical, is useful for the determination of the acceptable variance of the dimensions of magnet components. The second one, fully statistical, allows the study of the combined effect of many parameters. The use of these two methods allowed to evaluate with good confidence the robustness of two different dipole cross-section designs, featuring austenitic and aluminium alloy collars, respectively.

Robustness

Statistical Analysis

10.1109/77.828180

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Training Behavior of the Main Dipoles in the Large Hadron Collider

IEEE Transactions on Applied Superconductivity (2017)

E. Todesco Bernhard Auchmann M. Bajko L. Bottura Oliver Brüning

In 2015, the 1232 Nb-Ti dipole magnets in the Large Hadron Collider (LHC) have been commissioned to 7.8 T operational field, with 172 quenches. More than 80% of these quenches occurred in the magnets of one of the three cold mass assemblers (3000 series), confirming what was already observed in 2008. In this paper, the recent analysis carried out on the quench performance of the Large Hadron Collider dipole magnets is reported, including the individual reception tests and the 2008 and 2015 commissioning campaigns, to better understand the above-mentioned anomaly and give an outlook for future operation and possible increase of the operational field. The lower part of the quench probability spectrum is compatible with Gaussian distributions; therefore, the training curve can be fit through error functions. An essential ingredient in this analysis is the estimate of the error to be associated with the training data due to sampling of rare events, allowing to test different hypothesis. Using this approach, an estimate of the number of quenches required to reach 8.3 T (corresponding to the 7 TeV nominal energy) is given, and we propose to have two LHC sectors trained toward this target before the next warm up of the LHC.

10.1109/tasc.2017.2657504

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Development of the Superferric Sextupole Corrector Magnet for the LHC Luminosity Upgrade

IEEE Transactions on Applied Superconductivity (2016)

G. Volpini F. Alessandria G. Bellomo F. Broggi A. Paccalini

The National Institute for Nuclear Physics (INFN) is developing, within the framework of a collaboration agreement with the European Organization for Nuclear Research (CERN), prototypes of five corrector magnets, from skew quadrupoles to dodecapoles, which will equip the high-luminosity interaction regions of the high-luminosity Large Hadron Collider. These magnets are based on a superferric design, which allows a relatively simple, modular, and easy-to-construct magnet. In this paper, we review the main features of the corrector magnets, and we present the results of the manufacture of the sextupole superconducting coils, from the development of suitable solutions for the winding and impregnation to the quality assessment on the series coils, including the results of the first cryogenic tests on a single coil.

Upgrade

10.1109/tasc.2016.2543468

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Citations (20)