S. Sequeira Tavares

Swiss Federal Railways

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Véronique Michaud

École Polytechnique Fédérale de Lausanne

Susana Izquierdo Bermúdez

European Organization for Nuclear Research

S. Sgobba

European Organization for Nuclear Research

P. Ferracin

Lawrence Berkeley National Laboratory

Friedrich Lackner

European Organization for Nuclear Research

M. Bajko

European Organization for Nuclear Research

Michael Guinchard

European Organization for Nuclear Research

E. Todesco

European Organization for Nuclear Research

Lucio Fiscarelli

European Organization for Nuclear Research

D. W. Cheng

Lawrence Berkeley National Laboratory

Cooperative Institutions

European Organization for Nuclear Research

Fermi National Accelerator Laboratory

Lawrence Berkeley National Laboratory

Commissariat à l'Énergie Atomique et aux Énergies Alternatives

Brookhaven National Laboratory

Tianjin Hi-Tech Superconducting Electronic Technology (China)

École Polytechnique Fédérale de Lausanne

CEA Paris-Saclay

Fermi Research Alliance

Istituto Nazionale di Fisica Nucleare

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Manufacturing of thick skin honeycomb sandwich structures

S. Sequeira Tavares Y. Roulin Véronique Michaud Jan‐Anders E. Månson

Honeycomb

Honeycomb structure

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Mechanical characterization and assessment of the CMS conductor

IEEE Transactions on Applied Superconductivity (2000)

S. Sequeira Tavares Angela Calvo A. Desirelli S. Sgobba Ivan Horváth

The Compact Muon Solenoid (CMS) is one of the experiments which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.5m and the free aperture is 6 m in diameter. This is achieved with a 4 layer and 5 module superconducting Al stabilized coil, resulting into 20 lengths of conductor of 2.5 km each, energized at a nominal current of 20 kA at 4.5 K. One of the unique features of this thin solenoid is an Al-stabilized conductor reinforced by an Al-alloy. An extensive characterization of mechanical properties at room temperature and 4.2 K has been carried out in order to define the most appropriate alloy and temper for the reinforcement. The effect of the coil curing cycle on the alloy properties has been taken into account. This paper summarizes the main results of these tests.

Niobium-tin

Compact Muon Solenoid

Solenoid

10.1109/77.828257

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Citations (7)

Development of MQXF: The Nb<sub>3</sub>Sn Low-<inline-formula> <tex-math notation="LaTeX">$\beta$</tex-math></inline-formula> Quadrupole for the HiLumi LHC

IEEE Transactions on Applied Superconductivity (2015)

P. Ferracin G. Ambrosio M. Anerella A. Ballarino H. Bajas

The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-

$\beta$

(or inner triplet) quadrupole magnets. The use of Nb ₃ Sn superconducting material and, as a result, the possibility of operating at magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Européen pour la Recherche Nucléaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. This paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.

10.1109/tasc.2015.2510508

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Mechanical Properties of the CMS Conductor

IEEE Transactions on Applied Superconductivity (2004)

B. Curé B. Blau Alain Hervé P. Riboni S. Sequeira Tavares

CMS (Compact Muon Solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6 m diameter by 12.5 m long free bore, enclosed inside a 10000 ton return yoke. The magnetic field is achieved by a 4-layer superconducting solenoid made of a high purity aluminum (HPA) stabilized Rutherford type superconductor. The magnet is operated at 4.5 K, with a nominal current of 20 kA, for a total stored magnetic energy of 2.7 GJ. Due to the high magnetic forces at nominal field inside the winding pack, the structural component is the conductor itself to get a self-supporting winding structure. The mechanical reinforcement is made from aluminum alloy directly welded to the superconductor by electron beam (EB) welding technology before the winding operation. The external support cylinders also take part to the mechanical integrity. At each step of fabrication of the CMS conductor, the mechanical properties of the components and bonding between them are measured by destructive testing on short samples, in complement of continuous monitoring during production. This paper presents the results of the superconducting cable to pure aluminum shear testing, the tensile testing of the EN AW 6082 aluminum reinforcement, the insert to reinforcement shear testing, and the tensile testing of the full conductor before and after heat treatment induced during coil curing. Possible influence of the EB welding on the mechanical properties of the final conductor is investigated. Residual resistivity ratio (RRR) measurements of the HPA stabilizer are presented. Mechanical properties and equivalent RRR of the CMS conductor are presented for comparison with conductors of other geometry.

Niobium-tin

Electron beam welding

10.1109/tasc.2004.829712

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Design of Radiation Hard Spare Units for the Orbit Corrector Dipoles of LHC

IEEE Transactions on Applied Superconductivity (2020)

A. Louzguiti T. Sahner Daniel Schoerling S. Sequeira Tavares A. Tsinganis

Due to the High Luminosity upgrade of the Large Hadron Collider (HL-LHC), the orbit corrector dipoles located just before the interaction points of the accelerator will receive significantly increased gamma radiation doses, i.e., up to 20 MGy over the HL-LHC lifetime. Since these magnets were not designed to withstand such high gamma doses, new MCBC and MCBY magnets have to be designed and produced using radiation hard impregnation insulation and materials. In this paper, we describe both the gamma radiation campaign we are performing to determine the radiation hardness of the present MCBC and MCBY magnets and the new design and technologies that we have selected for the manufacturing of radiation hard spare units. We also discuss the impact of failing MCBC and MCBY magnets on the LHC and the foreseen alternative solutions.

Spare part

Orbit (dynamics)

10.1109/tasc.2020.2972223

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The CMS conductor

IEEE Transactions on Applied Superconductivity (2000)

Ivan Horváth B. Dardel H.-P. Marti J. Neuenschwander Richard P. Smith

The Compact Muon Solenoid (CMS) Is one of the experiments, which are bcing designed in the framcwork of the Large Hadron Collidcr (LHC) project at CERN.The deslgn field of lhe CMS magnet is 4 T, the magnetic length is 13 m and the aperture is 6 m.This hlgh magnetic field is achieved by means of A 4 layer, 5 modules superconducting soil.The col1 Is wound from an AI-stabilized Rutherford type conductor.The nominal current o f the magnet is 20 IrA rtt 4.5K In the CMS coil the structural function Is ensured, unlike in othcr cxisiing AI-stabilized thin solenoids, both by the AI-alloy reinforced conductor and the cxternal formcr.In this paper the retained manufacturing process of thc SO-km long reinforced conductor is described.In general the Rutherford type cable is surrounded by high purity aluminium In II contlnuous co-extrusion process to prorluce the Insert.Thereafter the reinforcement is joined by Electron Beam Welding to the pure AI of thc insert, bcforc bcing machlned to the final dimcnsions.During the manufacturc the bond quality between the Rutherford cable and thc high purlly rlumlnlum as well as the quality of the ER welding are continuously controlled by a now1 ultrasonlc phased array system.The diinenslons OC the insert and the final conductor arc mcasiired by Laser micrometer.'

Solenoid

Niobium-tin

10.1109/77.828256

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Citations (19)

Partially impregnated prepregs: how the through thickness air permeability correlates with the flow of the resin front during vacuum-bag only cure

S. Sequeira Tavares Véronique Michaud J.‐A. E. Månson

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Optimisation of Cordierite Processing through Taguchi Method

Materials science forum (2006)

Fernando A. Costa Oliveira S. Sequeira Tavares J.J.M.S. Domingues Jorge Cruz Fernandes Diamantino Dias

When applied to product engineering, the Taguchi method allows the identification of the conditions that lead to the development of similar products with a small variation around a particular target value. In the present work, the Taguchi method was used to evaluate the effect of four processing parameters on the mechanical properties of a commercial dense cordierite in order to maximize the flexural strength of the resulting bodies. Using a L9 orthogonal array, four control factors (named A, B, C and D) at three levels, namely type (AS1, AS2 and AS3) and content (18, 20 and 22 wt%) of alumina added, cooling rate (1, 3 and 5 °C⋅min-1) and average particle size of each batch (5, 6 and 7 μm) were set. Hence, with a reduced number of experiments, it was possible to identify the factors and their levels, which have most contributed to an increase in flexural strength of the resulting cordierite bodies. The optimum conditions to obtain bodies having a flexural strength higher than 100 MPa were the addition of 22 wt% of AS2 alumina, an average mixture particle size of 5 μm and a cooling rate of 1 °C⋅min-1. The type of alumina had a negligible effect on flexural strength whereas the other factors affect considerably the strength.

Orthogonal array

Cordierite

10.4028/www.scientific.net/msf.514-516.1448

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Citations (1)

Progress on the Development of the Nb3Sn 11T Dipole for the High Luminosity Upgrade of LHC

IEEE Transactions on Applied Superconductivity (2017)

F. Savary M. Bajko B. Bordini L. Bottura Lucio Fiscarelli

The high-luminosity large hadron collider (LHC) project at CERN entered into the production phase in October 2015 after the completion of the design study phase. In the meantime, the development of the 11 T dipole needed for the upgrade of the collimation system of the machine made significant progress with very good performance of the first two-in-one magnet model of 2-m length made at CERN. The 11 T dipole, which is more powerful than the current main dipoles of LHC, can be made shorter with an equivalent integrated field. This will allow creating space for the installation of additional collimators in specific locations of the dispersion suppressor regions. Following tests carried out during heavy ions runs of LHC in the end of 2015, and a more recent review of the project budget, the installation plan for the 11 T dipole was revised. Consequently, one 11 T dipole full assembly containing two 11 T dipoles of 5.5-m length will be installed on either side of interaction point 7. These two units shall be installed during the long shutdown 2 in years 2019-2020. After a brief reminder on the design features of the magnet, this paper describes the current status of the development activities, in particular the short model programme and the construction of the first full scale prototype at CERN. Critical operations such as the reaction treatment and the coil impregnation are discussed, the quench performance tests results of the two-in-one model are reviewed and finally, the plan toward the production for the long shut down 2 is described.

Upgrade

10.1109/tasc.2017.2666142

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Citations (32)

Assessment of 2-hour Images for 99m Tc-HYNIC-TOC Studies Using Image Interpretation and Image Analysis

S. Sequeira Tavares Maryam Jessop Deborah Pencharz Eleonora Manca Nitasha Singh

Poster: EANM 19 / TEPS-67 / Assessment of 2-hour Images for 99mTc-HYNIC-TOC Studies Using Image Interpretation and Image Analysis by: C. R. Tavares1, M. Jessop1, D. Pencharz1, E. Manca1, N. Singh1, S. Figueiredo2; 1Royal Sussex County Hospital, Brighton, , 2Lisbon School of Health Technology, Lisbon, PORTUGAL

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