Test Results of the First 3.7 m Long Nb3Sn Quadrupole by LARP and Future Plans

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The key objective of the Superconducting High Field Magnet work package of the European Project EuCARD, and specifically of the High Field Model task, is to design and fabricate the Nb3Sn dipole magnet FRESCA2. With an aperture of 100 mm and a target bore field of 13 T, the magnet is aimed at upgrading the FRESCA cable test facility at CERN. The design features four 1.5 m long double-layer coils wound with a 21 mm wide cable. The windings are contained in a support structure based on a 65 mm thick aluminum shell pre-tensioned with bladders. In order to qualify the assembly and loading procedure and to validate the finite element stress computations, the structure will be assembled around aluminum blocks, which replace the superconducting coils, and instrumented with strain gauges. In this paper, we report on the status of the assembly and we update on the progress on design and fabrication of tooling and coils. With an aperture of 100 mm and a target bore field of 13 T, the magnet is aimed at upgrading the FRESCA cable test facility at CERN. The design features four 1.5 m long double-layer coils wound with a 21 mm wide cable. The windings are contained in a support structure based on a 65 mm thick aluminum shell pre-tensioned with bladders. In order to qualify the assembly and loading procedure and to validate the finite element stress computations, the structure will be assembled around aluminum blocks, which replace the superconducting coils, and instrumented with strain gauges. In this paper, we report on the status of the assembly and we update on the progress on design and fabrication of tooling and coils.

Section: Quench Protection and Instrumentationmentioning

confidence: 97%

Development of the EuCARD $\hbox{Nb}_{3}\hbox{Sn}$ Dipole Magnet FRESCA2

Ferracin

Devaux

Durante

et al. 2013

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“…In the inner layer (IL), a "zig-zag" shape is employed with heating stations 25 mm long, 20 mm wide, and alternatively covering blocks near the pole and mid-plane turns. As an attempt to reduce the detachment of the trace from the coil experienced in previous LARP magnets [25], the copper sections are designed to be narrower to maximize the area of perforated polyimide. This solution will be examined after the magnet is tested to determine its efficacy.…”

Section: Quench Protectionmentioning

confidence: 99%

Development of MQXF: The Nb<sub>3</sub>Sn Low-<inline-formula> <tex-math notation="LaTeX">$\beta$</tex-math></inline-formula> Quadrupole for the HiLumi LHC

Ferracin

Ambrosio

Anerella

et al. 2016

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Abstract-The HiLumi LHC project has as the main objective to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new Interaction Regions lay-out, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the Interaction Points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating at magnetic field levels in the windings higher than 11 T, will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the US LHC Accelerator Research Program (LARP) and CERN, has now entered construction and test phase of the short models. Concurrently, the preparation for the development of the full length prototypes has been initiated. This paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.

“…This layout comes from the earlier design used in Long Quadrupoles (LQ) [15]. It involves regularly spaced heating stations separated by wider bridges (Fig.…”

Section: A Stainless Steel-only Designmentioning

confidence: 99%

Study of Quench Protection for the Nb₃Sn Low-β Quadrupole for the LHC Luminosity Upgrade (HiLumi-LHC)

Marinozzi

Ambrosio

Bellomo

et al. 2015

The HiLumi program is aiming to develop and build new Nb3Sn, high-field (12 T) and large aperture (150 mm) superconducting quadrupoles, which will be inserted in the LHC interaction regions and will provide the final focusing of the beam, in the program of the luminosity upgrade. The quench protection of these magnets is one of the most challenging aspects, mainly because of the large value of the magnet inductance (160 mH for the configuration with two 8 m long magnets in series), of the large value of the stored magnetic energy density in the coils (0.12 J/mm3, a factor 2 larger than in the conventional NbTi quadrupoles) and of the use of Nb3Sn as conductor, which has never been used for large accelerator magnets. Previous works have demonstrated that a "standard" conservative analysis, assuming quench heaters only on the coils outer layer, gives high hot spot temperature, close to the design limit (350 K). In this paper, a new study of quench protection is presented. The benefic effects of large dI/dt during the discharge and other dynamic effects are discussed together with options for having a partial coverage of the inner layer by quench heaters. The analysis is validated by experimental data from R&D Nb3Sn quadrupole magnets.