Status of the Construction of the CMS Magnet

Hervé, A.; Blau, B.; Brédy, P.; Campi, D.; Cannarsa, Piermarco; Curé, B.; Dupont, T.; Fabbricatore, P.; Farinon, S.; Feyzi, F.; Fazilleau, Philippe; Gaddi, A.; Gerwig, H.; Greco, M.; Grillet, J.P.; Kaftanov, V.; Kircher, F.; Klyukhin, V.; Levesy, B.; Loveless, R.; Maire, G.; Musenich, R.; Pabot, Y.; Payn, A.; Perinić, G.; Petiot, P.; Rondeaux, F.; Rykaczewski, H.; Sbrissa, E.; Tavares, S. Sequeira; Sgobba, S.; Smith, R. P.; Veillet, L.; Waurick, G.

doi:10.1109/tasc.2004.829715

“…Distinctive features of the CMS detector include a high magnetic field solenoid coupled with a multilayer muon system, a fully active scintillating crystal electromagnetic calorimeter, a tile hadronic calorimeter, and a pow- erful inner tracking system. The design field of the superconducting CMS solenoid is 4 T, the magnetic length is 12.5 m and the free diameter of the bore is 6 m [1]. As reported previously in detail, e.g., in [2], the main peculiarity of the CMS magnet among other existing thin detector solenoids is its sandwich-type aluminum-stabilized superconductor.…”

Section: Introductionmentioning

confidence: 82%

Superconducting Strand Properties at Each Production Stage of the CMS Solenoid Conductor Manufacturing

Blau

¹

,

Campi²,

Curé³

et al. 2004

IEEE Trans. Appl. Supercond.

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Abstract-The Compact Muon Solenoid (CMS) detector is one of the general-purpose particle detectors presently being built for the LHC project at CERN. The superconducting CMS solenoid will produce a magnetic field of 4 T in a bore 6 m in diameter and 12.5 m long. The coil is wound from 20 high purity aluminum-stabilized NbTi conductors with a total length of 45 km. The main part of the structural integrity of the CMS coil is ensured by aluminum-alloy reinforcement welded to the high purity aluminum stabilizer of the conductor. The Rutherford type superconducting cable within the stabilizer consists of 32 copper-stabilized multifilamentary NbTi strands each with Nb barrier. The strands are optimized with respect to a high critical current density ( 3000 A mm 2 at 5 T, K).Approximately 1950 km of superconducting strand has been produced from 148 extrusion billets and cabled in unit lengths of 2.65 km. All strands within a cable can unambiguously be identified by distinctive patterns of the NbTi filaments. The statistics of measurements, n-value, copper RRR and (Cu + Nb) NbTi ratio are presented. Since the strands are subjected to potentially dangerous high temperatures and mechanical strain during the different conductor production steps it was important to trace the critical current properties of the strand as it progressed through the conductor fabrication process. The paper presents results of measurements, which were performed on all individual strands extracted from conductor samples taken at each step of the manufacturing process. The comparison among the measurements assured accurate quality control during the whole process of conductor production. In addition, measurements in fields up to 6 T on the complete CMS conductors using the MaRiSA test facility are reported.

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“…From the mechanical analysis [7], the bonding was specified at a minimum value of 20 MPa at room temperature (RT), which includes a safety factor on the maximum computed shear stresses at 4.2 K. The measurements on samples taken at the head and tail of each insert length are summarized on Fig. 3 for the total production of 21 insert units, including the length used for the prototype coil [1]. At RT, the shear stress at head is 38.0 3.2 MPa, and the shear stress at tail is 32.4 5.2 MPa, with a minimum measured shear stress value equal to 21 MPa.…”

Section: A Bonding Of Hpa Stabilizer To Superconducting Cablementioning

confidence: 99%

Mechanical Properties of the CMS Conductor

Curé

¹

,

Blau

²

,

Hervé

³

et al. 2004

IEEE Trans. Appl. Supercond.

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Abstract-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.

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“…T HE CMS experiment (Compact Muon Solenoid) is a general-purpose, proton-proton detector designed to run at the highest luminosity of the LHC [1]. Distinctive features of the CMS detector include a high-magnetic-field solenoid (4 T) coupled with a multilayer muon system, a fully active scintillatingcrystal electromagnetic calorimeter, a tile hadronic calorimeter, and a powerful inner tracking system.…”

Section: Introductionmentioning

confidence: 99%

The Construction of the Modules Composing the CMS Superconducting Coil

Fabbricatore

¹

,

Campi

²

,

D'Urzo

³

et al. 2004

IEEE Trans. Appl. Supercond.

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Abstract-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 a 6 m diameter by 12.5 m long free bore, enclosed inside a 10,000-ton return yoke. The construction of the five modules composing the coil is presently under way. The methods for constructing large aluminum alloy mandrels, for winding the reinforced conductor with high accuracy of the winding pack and for impregnating the single large modules (50 t) have been assessed through the construction of a module prototype. The prototype has the same radius as a CMS module (6900 mm outer diameter), but a shorter axial length (670 mm against 2500 for the module). The relevant technological result was the understanding of the methods for obtaining a large coil with a very limited shape deformation ( 2.5 mm on diameter) for allowing the precise mounting of the modules. This paper describes the main technical issues of the prototype and of the construction of the first modules, the geometrical and RT tests performed on them and the common problems related to the series construction of large superconducting coils.

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Status of the Construction of the CMS Magnet

Abstract: Abstract-CMS (Compact MuonSolenoid

Cited by 32 publications

References 18 publications

Superconducting Strand Properties at Each Production Stage of the CMS Solenoid Conductor Manufacturing

Superconducting Strand Properties at Each Production Stage of the CMS Solenoid Conductor Manufacturing

Mechanical Properties of the CMS Conductor

The Construction of the Modules Composing the CMS Superconducting Coil

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