Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-23T06:03:39.106Z Has data issue: false hasContentIssue false
  • English
  • Français

Reliability oriented optimum design of the Large Hadron Collider magnet-to-magnet interconnections

Published online by Cambridge University Press:  24 February 2004

Cédric Garion ,
Didier Marquis  and
Blazej Skoczen
Cédric Garion
Affiliation:
CERN, LHC Division, 1211 Geneva 23, Switzerland
Didier Marquis
Affiliation:
IFMA, Campus des Cézeaux, BP 265, 63175 Aubières Cedex, France
Blazej Skoczen
Affiliation:
CERN, LHC Division, 1211 Geneva 23, Switzerland
Get access

Abstract

The quest for high particle energies of modern super conducting lepton and hadron storage rings assumes a strong minimisation of the non-magnetic interconnection zones when compared to the total magnetic length of the main quadrupoles and the dipoles. The ratio of non-magnetic to magnetic zones in the LHC is close to 3%. Such a low percentage leads to a very compact design of systems and sub-systems situated in the interconnections, like the mechanical compensation system, composed of the bellows expansion joints, that have to compensate for the thermal contraction of the magnets. Given the complexity of the LHC interconnections, the requirements concerning their reliability were considerably increased since the availability of the collider for physics cannot be compromised. The failure modes taken into account in the present analysis are grouped into 3 categories: material failures, structural stability failures and fatigue failures. Optimisation of stainless steel for cryogenic applications has been carried out. Also, a concept of reliability oriented parametric optimisation of the LHC interconnections is presented.

Keywords

Bellows expansion jointscryogenic temperaturesreliabilitydamagemartensitic transformationfatiguestabilityWeibullSoufflets de compensationtempératures cryogéniquesfiabilitéendommagementtransformation martensitiquefatiguestabilitéWeibull
Type
Research Article
Information
Mechanics & Industry , Volume 5 , Issue 1 , January 2004 , pp. 87 - 101
Copyright
© AFM, EDP Sciences, 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

B. Skoczen, Stability, fatigue and optimization of thin-walled structures under cryogenic conditions. Application in the structural design of colliders and cryogenic transfer lines., CERN Yellow Report, CERN-2001-001, Geneva (2001)
B. Skoczen, Local stability of cryogenic pipelines and cryomagnet interconnections – effect of fatigue damage evolution on buckling, ASME PVP2000 Conference, Seattle, published in PVP-Vol. 401, ASME (2000)
J. Lemaitre, A Course on Damage Mechanics, Springer-Verlag (1992)
C. Garion, B. Skoczen, Plastic strain induced damage evolution and martensitic transformation in ductile materials at cryogenic temperatures, Proceedings of the International Cryogenic Materials Conference, ICMC (2001), Madison, USA, Advances in Cryogenic Engineering, Vols. 47 and 48, New York, (2001)
C. Garion, B. Skoczen, Modeling of plastic strain induced martensitic transformation for cryogenic applications, ASME J. Appli. Mech. 69 (2002)
K. Suzuki, J. Fakakura, H. Kashiwaya, H., Cryogenic fatigue properties of 304 L and 316L stainless steels compared to mechanical strength and increasing magnetic permeability, J. Test. Evaluation 16
M.L. Delsante, C. Garion, S. Sgobba, B. Skoczen, Experimental analysis of the plastic strain induced martensitic transformation in 316L stainless steel at cryogenic temperatures and identification of the relevant constitutive equations, CERN Technical Note, EDMS n° 411336
B. Skoczen, Local stability of cryogenic pipelines and cryomagnet interconnections – generalised equivalent column concept, ASME PVP2000 Conference, Seattle, published in PVP-Vol. 401, ASME (2000)
E.L. Axelrad, Flexible Shells, Moskva, Nauka in Russian (1976)
B. Skoczen, Effect of Shear Deformation and Relaxation of Support Conditions on Elastic Buckling of Pressurised Expansion Bellows, ASME Journal of Pressure Vessel Technology, 121 (1999), pp. 127–132
B. Skoczen, Generalisation of the Coffin equations with respect to the effect of large mean plastic strain, ASME Journ. Eng. Mat. Techn., 118, July (1996)
D.C. Larbalestier, H.W. King, Austenitic stainless steels at cryogenic temperatures – Part I: structural stability and magnetic properties, Cryogenics 13, 160–167 (1973)
EJMA STANDARDS, Standards of the Expansion Joint Manufacturers Association, Inc., New York, USA, (1995)
I. Kovalenko I., N.Y. Kuznetsov, Ph.A. Pegg, Mathematical theory of reliability of time depend systems with practical applications, John Wiley & Sons Ltd., (1997)
C. Garion,B. Skoczen, Reliability oriented optimum design of the LHC interconnections. Part I: mechanical compensation system, LHC Project Note 245, EDMS 249743, CERN (2000)