Status of the short dipole model program for the LHC

Artoos, Kurt; Bottura, L.; Fessia, P.; Perini, D.; Sanfilippo, S.; Siegel, N.; Siemko, A.; Tommasini, D.; Vanenkov, I.; Walckiers, L.; Wyss, C.

doi:10.1109/77.828173

Cited by 12 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…About 34 1-m-long model dipole magnets of the 2nd generation, denominated MBSMS1 to 23 and MBSMT1 to 11, were produced at CERN from 1995 to 1999, [3], [12]. They have been assembled with one, or with two apertures, in the five block, and in the six block coil geometries (Fig.…”

Section: A Data Reductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of the Transfer of Heat From the Coil of the LHC Dipole Magnet to Helium II

Richter

Fleiter

Baudouy

et al. 2007

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

Abstract-During operation of the Large Hadron Collider at CERN, heat will be generated inside the coils of its superconducting magnets as a consequence of ramping of magnetic field, and of the interaction of lost beam particles with the magnet mass. Heat has to be transferred from the conductor into the He II coolant and removed from the magnet environment.During the LHC R&D stage, this transfer has been extensively studied on simulated coil segments at CEA/Saclay, and by analyzing dynamic behavior of short model magnets at CERN.Owing to the importance of efficient cooling for the design of future superconducting accelerator magnets, study of heat transfer has been restored at CERN and in frame of the Next European Dipole Collaboration.The article features two recently performed works: 1) Attempt to analyse archived high ramp rate quench data of 1-m-long LHC model dipole magnets of the 2nd generation. 2) Development of a method for direct measurement of heat transfer on segments of production LHC dipole magnet coils.

show abstract

Section: A Data Reductionmentioning

confidence: 99%

“…The models were extensively tested in vertical Claudet-bath cryostats, [3], [12]- [14]. Without the beam pipe installed, He II freely accessed the inner surface of the coils, which is the main cooling surface in LHC dipole magnets.…”

Section: A Data Reductionmentioning

confidence: 99%

Evaluation of the Transfer of Heat From the Coil of the LHC Dipole Magnet to Helium II

Richter

Fleiter

Baudouy

et al. 2007

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

show abstract

“…On the other hand, superconducting accelerator magnets have proven in many cases that coil unloading during the magnet ramp does not prevent reaching higher currents. This was observed for the SSC prototypes ( [7], page 1358), in short models for the LHC dipoles [8], and more recently in short models for MQXF quadrupoles [9,10] and in short models for the 11 T dipole [10,11]. The guidelines for coil preload are particularly relevant for high field or large aperture Nb3Sn magnets, since stress scales with aperture, field and current density ( [12], page 6), and the requirement on full preload risks to approach the degradation levels of the superconductor.…”

Section: Introductionmentioning

confidence: 61%

Performance of a MQXF Nb₃Sn Quadrupole Magnet Under Different Stress Level

Bermúdez

Ambrosio

Bordini

et al. 2022

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

In a dipole or in a quadrupole accelerator magnet, the displacement of the coil turns induced by the electromagnetic forces can cause quenches limiting the magnet performance. For this reason, an azimuthal preload is applied to avoid azimuthal movements of the coil up to the required operational current. However, several tests showed that accelerator magnets can operate with a partial preload, i.e. that coil unloading during the ramp does not prevent reaching higher currents. This issue is particularly relevant for Nb3Sn magnets, where the loads applied to the Nb3Sn filaments can reach the degradation limits of critical current. In order to investigate the impact of coil preload on the quench performance, the MQXFS6 short model quadrupole for the High Luminosity Upgrade was tested under an azimuthal preload at 80% of the short sample current, reaching 93% of short sample current at 1.9 K. The preload was then released to 60%, still showing ability to operate in the range of 80-85% of short sample current as required by HL-LHC project. With this lower preload, the ability of going above 90% of short sample was lost, and a significant training appeared above 85%. When the preload was restored to the original 80% value, the magnet reached with few quenches 95% of short sample (13.4 T peak field). Magnetic measurements confirm the larger movement of the coil in the case with lower preload, and agree with finite element simulations.

show abstract

“…In the main dipole for the LHC [3], the particle accelerator under construction at CERN (Geneva), the mechanical structure which confines the coil consists of the austenitic steel collars, the iron yoke and shrinking cylinder (see FIGURE 1). The nominal pre-stress exerted by the collar on the coil at the end of the magnet assembly before the cool-down is of about 70 MPa.…”

Section: Introductionmentioning

confidence: 99%

Thermal contraction measurements of the superconducting coil of the main magnets for the Large Hadron Collider

Ferracin¹,

Todesco²,

Tommasini³

et al. 2002

AIP Conference Proceedings

View full text Add to dashboard Cite

We analyse the problem of defining and measuring the thermal contraction in the superconducting coil of the Large Hadron Collider main magnets. Since an unloaded coil length cannot be precisely defined, one has to use methods based on the pre-stress loss from room temperature to cryogenic temperature. A very strong dependence of the thermal contraction coefficient on the conventions used for defining coil deformations is discussed. Moreover, one finds different values of the thermal contraction coefficient according to the pressure imposed at room temperature before the cooling down. A pressure-dependent thermal contraction coefficient can be therefore worked out. ABSTRACTWe analyse the problem of defining and measuring the thermal contraction in the superconducting coil of the Large Hadron Collider (LHC) main magnets. Since an unloaded coil length cannot be precisely defined, one has to use methods based on the prestress loss from room temperature to cryogenic temperature. A very strong dependence of the thermal contraction coefficient on the conventions used for defining coil deformations is discussed. Moreover, one finds different values of the thermal contraction coefficient according to the pressure imposed at room temperature before the cooling down. A pressure-dependent thermal contraction coefficient can be therefore worked out.

show abstract

Status of the short dipole model program for the LHC

Abstract: Abstract

Cited by 12 publications

References 3 publications

Evaluation of the Transfer of Heat From the Coil of the LHC Dipole Magnet to Helium II

Evaluation of the Transfer of Heat From the Coil of the LHC Dipole Magnet to Helium II

Performance of a MQXF Nb₃Sn Quadrupole Magnet Under Different Stress Level

Thermal contraction measurements of the superconducting coil of the main magnets for the Large Hadron Collider

Contact Info

Product

Resources

About

Status of the short dipole model program for the LHC

Abstract: Abstract

Cited by 12 publications

References 3 publications

Evaluation of the Transfer of Heat From the Coil of the LHC Dipole Magnet to Helium II

Evaluation of the Transfer of Heat From the Coil of the LHC Dipole Magnet to Helium II

Performance of a MQXF Nb3Sn Quadrupole Magnet Under Different Stress Level

Thermal contraction measurements of the superconducting coil of the main magnets for the Large Hadron Collider

Contact Info

Product

Resources

About

Performance of a MQXF Nb₃Sn Quadrupole Magnet Under Different Stress Level