Test Result of the Short Models MQXFS3 and MQXFS5 for the HL-LHC Upgrade

Bajas

et al. 2018

Self Cite

Abstract-CERN and US LARP (LHC Accelerator Research Program) are jointly developing Nb3Sn quadrupole magnets to be installed in the LHC for its upgrade to higher luminosity. These magnets' quench protection system will include a combination of quench heaters attached to the coil surfaces and CLIQ units electrically connected to the magnets. Different protection elements have been characterized separately and simultaneously by implementing them on two 1.2 meter long model quadrupole magnets, tested at FNAL and CERN, and one 4.0 meter long mirror magnet tested at BNL. After analyzing the test data, their performances have been positively evaluated. Furthermore, the electro-thermal transients occurring after a quench have been simulated with the LEDET software and the results compared to experimental results. The preferred quench protection system configuration relies both on heaters and CLIQ. This solution is based on electrically robust components, achieves an effective reduction of the coils hot-spot temperature after a quench, and offers increased redundancy against component failures.

“…[29], [30]. b. MQXFS3 magnet [26]- [28]. Values are calculated from the manual quench detection triggering.…”

Section: A Experimental Resultsmentioning

confidence: 99%

Section: Parametermentioning

confidence: 99%

Section: A Heatersmentioning

confidence: 99%

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Quench Protection Performance Measurements in the First MQXF Magnet Models

Ravaioli

Bajas

et al. 2018

Self Cite

“…In both cases the magnet failed to reach the ultimate current. The increased prestress produced, however, some beneficial effects on the magnet performance [7]. The degraded quenches were all localized in one coil, that was subsequently swapped.…”

Section: Mqxf Short Model Magnetsmentioning

confidence: 99%

Summary of the Mechanical Performances of the 1.5 m Long Models of the Nb<inline-formula> <tex-math notation="LaTeX">$_{3}$</tex-math> </inline-formula>Sn Low-<inline-formula> <tex-math notation="LaTeX">$\beta$</tex-math> </inline-formula> Quadrupole MQXF

Vallone

Anderssen

et al. 2019

Self Cite

The Nb 3 Sn quadrupole MQXF is being developed as a part of the LHC High Luminosity upgrade. The magnet design was tested on 1.5 m long short models, sharing the same cross-section with the full-length magnets. Various azimuthal and longitudinal preloads were applied, studying the impact on the magnet training and on its mechanical performances. The experiments demonstrated the possibility to control the magnet prestress. However, various factors, coil size among the others, may affect the stress variation between and within each winding. This variation could prevent the magnet to reach the desired performances, for example as result of critical current degradation of the Nb 3 Sn strands. This paper analyzes the mechanical performances of the short models, studying in particular the stress variation on different coils. The measured coil size was used as input in the numerical simulations, and results were then compared with the strain gauge measurements. Finally, the short models experience was used to evaluate the feasibility of a loading operation that does not rely on the strain measurements.

“…1, and will produce an ultimate gradient of 143.2 T/m in a 150 mm aperture, when powered at 17.89 kA. The design was tested in four short models [4]: the MQXFS1 [5], [6], MQXFS5 [7] and MQXFS4 [8] magnets successfully reached the ultimate current, while MQXFS3 [7] did not.…”

Section: Introductionmentioning

confidence: 99%

Assembly of a Mechanical Model of MQXFB, the 7.2-m-Long Low-<inline-formula> <tex-math notation="LaTeX">$\beta$</tex-math> </inline-formula> Quadrupole for the High-Luminosity LHC Upgrade

Vallone

Anderssen

et al. 2019

Self Cite

The Nb 3 Sn low-β quadrupole MQXF is being developed as a part of the High-Luminosity LHC upgrade project. The magnet will be produced in two different configurations, sharing the same cross-section but with different lengths. A 7.2 m mechanical model of MQXFB was recently assembled at CERN with one copper coil, two low-grade coils and one rejected coil. Coil dimensions were measured with a portable Coordinate Measurement Machine. The coil pack shimming was designed in order to optimize the field quality and the contacts between the coils and the collars. The azimuthal preload target was defined using the short models experience. The mechanical behavior during loading was monitored by means of strain gauges. The results demonstrated that the structure can provide the required prestress to the coils.