Assembly, Loading, and Cool-Down of the FRESCA2 Support Structure

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FRESCA2 is a dipole magnet dedicated to upgrade the present CERN cable test station FRESCA to a nominal bore field of 13 Tesla (T) in a 100 mm clear aperture. This paper reports on the assembly process and the three cool-down tests to cryogenic temperature of the support structure of FRESCA2. This structure is based on an aluminum alloy shrinking cylinder pre-loaded through the use of water-pressurized bladders. To verify the assembly and loading processes, this structure was assembled using full block aluminum alloy "dummy coils" standing for the Nb 3 Sn coils. Then, the whole assembled structure was cooled-down to 77 K with liquid nitrogen in a dedicated facility at CERN. The mechanical behavior was monitored at all stages by strain gauges located on different components of the structure. Three cryogenic tests were made by increasing the loading gradually up to values corresponding to the ultimate field of 15 T. The expected stresses within the structure after assembly, loading and cool-down were determined from the 3-D finite-element model of the support structure. A comparison of the model predictions with the strain gauge data is presented.

Section: A Cross-sectionsupporting

confidence: 68%

Mechanical Validation of the Support Structure of the $\hbox{Nb}_{3}\hbox{Sn}$ Magnet FRESCA2

Garcia¹,

Bajas²,

Bajko³

et al. 2015

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“…The internal thermometry in vacuum conditions has to measure the temperature of SC cables at voltage of 1 kV, joints and other points in the magnet structure. FRESCA2 is a 100 mm aperture Nb 3 Sn dipole magnet, generating a bore field of 13 T [6][7]. It has a massive 10 tons support structure to withstand forces between coils.…”

Section: Introductionmentioning

confidence: 99%

Precise Thermometry for Next Generation LHC Superconducting Magnet Prototypes

Datskov

Kirby

Bottura

et al. 2014

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Abstract-The next generation of LHC superconducting magnets is very challenging and must operate in harsh conditions: high radiation doses in a range between 10 and 50 MGy, high voltage environment of 1 to 5 kV during the quench, dynamic high magnetic field up to 12 T, dynamic temperature range 1.8 K to 300 K in 0.6 sec. For magnet performance and long term reliability it is important to study dynamic thermal effects, such as the heat flux through the magnet structure, or measuring hot spot in conductors during a magnet quench with high sampling rates above 200 Hz. Available on the market cryogenic temperature sensors comparison is given. An analytical model for special electrically insulating thermal anchor (Kapton pad) with high voltage insulation is described. A set of instrumentation is proposed for fast monitoring of thermal processes during normal operation, quenches and failure situations. This paper presents the technology applicable for mounting temperature sensors on high voltage superconducting (SC) cables. The temperature measurements of fast heat crosspropagation in MQXC SC cable and FCM dynamic tests are also presented. Novel thermometry has been successfully applied to a few CERN magnet prototypes (MQXC, FCM and FRESCA2).

“…[7]. The mechanical structure assembly and test are reported in [8]. Heat transfer studies have been addressed in [9].…”

Section: Introductionmentioning

confidence: 99%

Development and Coil Fabrication Test of the $ \hbox{Nb}_{3}\hbox{Sn}$ Dipole Magnet FRESCA2

Manil

Baudouy

Clément

et al. 2014

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The key objective of the High Field Magnet work package of the European Project EuCARD is to design and fabricate the Nb 3 Sn dipole magnet FRESCA2. It has an aperture of 100 mm and a target bore field of 13 T. The design features four 1.5 m long double-layer coils wound with a 21 mm wide cable. The project has now entered its experimental phase in view of the magnet fabrication. We present the experimental test campaign conducted on cable samples in order to understand and to control better the cable behavior and geometry. One full scale double-layer coil using copper cable with the final dimensions and insulation scheme has been wound and heat treated in order to check the fabrication process. This has given useful feedback on the fabrication procedure and on the expected magnet dimensions, as well as on the tooling itself.