Steering Field Quality in the Main Dipole Magnets of the Large Hadron Collider

Todesco, E.; Bellesia, B.; Bottura, L.; Devred, A.; Remondino, V.; Pauletta, S.; Sanfilippo, S.; Scandale, W.; Vollinger, Christine; Wildner, E.

doi:10.1109/tasc.2004.829039

Cited by 19 publications

(19 citation statements)

References 7 publications

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“…The MB geometric value is optimized to partially compensate the magnetization component. The agreement for b 3 in the MB is about 1 unit for all three cross-sections, but it is much worse (up to 5 units) for the separation dipoles. We believe this is due to our inaccurate knowledge of the coil geometry.…”

Section: B Transfer Functionmentioning

confidence: 83%

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Comparison between Electromagnetic Models and Magnetic Measurements in the LHC Magnets

Hagen

Auchmann

Todesco

2012

IEEE Trans. Appl. Supercond.

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We present a comparison between the electromagnetic model of the main LHC magnets and the magnetic measurements carried out during production. The goal of this study is to test the validity range of the model and to uncover discrepancies between models and reality. We de-compose the field computation into several parts: geometry (coils, collars, and yoke), persistent currents in the superconducting cables, and saturation of the iron yoke. For each component we give the agreement between model and measurements. This gives an indication about the precision one can expect to obtain from a simulation code -this information is particularly relevant for future upgrades of the LHC. CERN-ATS-2012-026February 2012 Abstract 2IP1-1 EDMS 1138818 1 Abstract-We present a comparison between the electromagnetic model of the main LHC magnets and the magnetic measurements carried out during production. The goal of this study is to test the validity range of the model and to uncover discrepancies between models and reality. We decompose the field computation into several parts: geometry (coils, collars, and yoke), persistent currents in the superconducting cables, and saturation of the iron yoke. For each component we give the agreement between model and measurements. This gives an indication about the precision one can expect to obtain from a simulation code -this information is particularly relevant for future upgrades of the LHC.

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Section: B Transfer Functionmentioning

confidence: 83%

“…The experimental data are the magnetic measurements carried out during the production [2], [3]. All magnets have been measured at room temperature, and a fraction of them in operational conditions (1.9 or 4.2 K).…”

Section: Introductionmentioning

confidence: 99%

Comparison between Electromagnetic Models and Magnetic Measurements in the LHC Magnets

Hagen

Auchmann

Todesco

2012

IEEE Trans. Appl. Supercond.

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“…Field harmonics are first measured at room temperature at the manufacturers after the collaring and after the assembly of the cold mass with a rotating coil of 750 mm length [3] so as to detect faulty components or assembly procedures and get a picture of the geometric field errors. The cold measurements are performed in the cryo-magnets at the CERN test stations.…”

Section: Test Procedures and Measurementsmentioning

confidence: 99%

“…The series tests started in June 2001 and were completed in February 2007. The test program for dipoles and quadrupoles included field quality measurements that were carried out at room temperature over 100% of the production and over a sample of 15-20% in operational conditions in order to steer the magnetic quality towards the beam requirements [3]. In this paper we present the field quality results related to the main LHC superconducting magnets.…”

Section: Introductionmentioning

confidence: 99%

“…All types of cross-section and cable combinations were tested at cold and the magnet number allows establishing meaningful statistical results. The shape of the field imperfections is modeled using a Gaussian distribution with average and standard deviation of magnets measured at cold or extrapolated from room temperature based on the warm to cold correlations established for the dipoles [3] and the main quadrupoles [5].…”

Section: Introductionmentioning

confidence: 99%

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Magnetic Performance of the Main Superconducting Magnets for the LHC

Sanfilippo

Sammut

Bottura

et al. 2008

IEEE Trans. Appl. Supercond.

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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.

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Magnets for Particle Accelerators and Colliders

Bottura

Rossi

2016

Digital Encyclopedia of Applied Physics

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The article contains sections titled: Introduction Accelerators, Colliders, and Role of Superconducting Magnets Magnetic Design Mechanical Design Margins, Stability, Training, and Protection Field Quality Fast‐Cycled Synchrotrons Acknowledgments

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Steering Field Quality in the Main Dipole Magnets of the Large Hadron Collider

Cited by 19 publications

References 7 publications

Comparison between Electromagnetic Models and Magnetic Measurements in the LHC Magnets

Comparison between Electromagnetic Models and Magnetic Measurements in the LHC Magnets

Magnetic Performance of the Main Superconducting Magnets for the LHC

Magnets for Particle Accelerators and Colliders

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