Fabrication of the Pre-Series Wide Aperture Superconducting Quadrupoles for the LHC Insertions

Abstract-The field strength and homogeneity of all the LHC superconducting magnets were measured as a part of the production control and qualification process that has taken place during the past four years. In addition to field measurements at room temperature performed on the integral of the production, a significant part of the magnets has been subjected to extensive magnetic measurements at cold. The measurements at cryogenic temperatures, generally performed up to excitation currents of 12 kA corresponding to the ultimate LHC energy of 7.6 TeV, were mainly based on static and dynamic field integral and harmonic measurements. This allowed us to study in detail the DC effects from persistent current magnetization and long-term decay during constant current excitation. These effects are all expected to be of relevance for the field setting and error compensation in the LHC. This paper reports the main results obtained during these tests executed at operating conditions. The integrated field quality is discussed in terms of distribution (average and spread) of the field strength and low-order harmonics as obtained for all the main ring magnet families (dipoles, main and matching quadrupoles). The dependence of field quality on coil geometry, magnet and cable manufacturer is analyzed. A projection of the field quality expected for the critical components in the machine is presented.

Section: Magnet Design Features and Test Proceduresmentioning

confidence: 99%

“…The dipole and quadrupole assemblies are described in [6] and that of the matching quadrupoles in [8]. The superconducting coils are clamped in austenitic steel collars inside an iron yoke, the whole structure being contained in a shrinking cylinder.…”

Section: Coil Assembly and Magnet Parametersmentioning

confidence: 99%

Magnetic Performance of the Main Superconducting Magnets for the LHC

Sanfilippo

Sammut

Bottura

et al. 2008

“…The first pre-series magnet has been completed in September 2003 and delivered for qualification tests at CERN [12]. As the contractor is also manufacturing the LHC arc quadrupoles, experienced staff are available for rapid ramping-up of the fabrication.…”

Section: Dispersion Suppressors and Matching Sectionsmentioning

confidence: 99%

Superconducting Magnets for LHC Insertions

Ostojić

2004

Self Cite

Abstract-The LHC comprises eight insertions, four of which are dedicated to the experiments while the others are used for major collider systems. The various functions of the insertions are fulfilled by a variety of magnet systems, most of them based on the technology of NbTi superconductors cooled by superfluid helium at 1.9 K. In this paper, we review the concepts underlying the design of the LHC insertions, and describe the corresponding design of the various specialized magnet systems. A status of the procurement of the magnets is given, and plans for their installation and commissioning reviewed.

“…Precision alignment cradles are used, in the first instance to individually align the magnets, which are not aligned during yoke assembly [1], [2]. The yoke laminations have alignment flats designed as contact surfaces for the tooling, and also as references for control.…”

Section: A Magnet Alignmentmentioning

confidence: 99%

“…These units comprise several quadrupole magnets of the MQM or MQY type [1], [2], arranged to give the necessary field strength. In the dispersion suppressors (quadrupole cells Q8 to Q10), the quadrupoles are part of the continuous arc cryostat, operate at 1.9 K, and although independently powered, provide identical cryogenic and powering interfaces to the adjacent main dipoles as in the regular arc cells.…”

Section: Introductionmentioning

confidence: 99%

Design and Assembly of the Pre-Series Quadrupoles for the LHC Insertions

Ostojić

Lucas

Kirby

et al. 2004

Self Cite

Abstract-The LHC insertions are equipped with several different types of individually powered superconducting quadrupoles. These units comprise several quadrupole magnets and orbit correctors, and range in length from 5.3 m to 11.3 m. In spite of the variety of types and interface requirements, the design of the quadrupoles is based on the same principle where two welded half-shells provide the rigidity and alignment of the magnets and serve as a helium pressure vessel. In this paper we present the mechanical design of the LHC insertion quadrupoles, describe the initial experience in the assembly of the pre-series units, and report on the alignment measurements.