The LEAS (Laboratoire d'Etude des Aimants Supraconducteurs) at CEA Paris-Saclay has entirely manufactured a coil based on the superconductor Nb3Sn (niobium-tin), of the SMC (Short Model Coil) type. This coil is a short model intended to be assembled in a magnet structure, then to be tested at cryogenic temperature. Nb3Sn is being considered for future accelerator magnets generating magnetic fields up to 16 T (teslas), which would double the performance of the best magnets currently in use. However, this requires a great deal of technological development. This type of short coil has been developed by Cern, in collaboration with the CEA, to allow the testing of new technologies and new manufacturing processes under conditions representative of future high-field magnets. The fabrication of the SMC-CEA coil took place at LEAS from May to October 2021, then the coil was delivered to Cern to be assembled in a structure, and finally tested in a liquid and superfluid helium bath, under high current, in a dedicated station. The tests delivered encouraging results, demonstrating that LEAS is one of the few European laboratories that now has all the capabilities to manufacture Nb3Sn superconducting coils. This proof of feasibility validates the first step of the development program of high field magnets for future accelerators.

The large aperture (90 mm) quadrupole superconducting electromagnet for the CERN HL-LHC project, manufactured and tested at 4.2 K by the IRFU teams, reached its nominal gradient of 120 T/m (defined for 1.9 K) the 5th of March, 2021. These very good results validate the design and manufacturing process proposed by the IRFU engineers and were the subject of a technology transfer to the industrial companies working on the European project QuaCo (QUAdrupoleCOrector). This magnet was produced as part of the LHC upgrade in luminosity project called HiLumi-LHC. These NbTi magnets are part of the insertion magnets. They may be placed upstream and downstream of detectors such as ATLAS and CMS at the center of which the 2 beams cross to make the collisions. They should ensure the compression of the beams before collisions and thus contribute to increasing the integrated luminosity of the HL-LHC (i.e. the total number of collisions), up to ten times greater than the initial nominal value of the LHC.

Since the restart of the LHC on 20 November, CMS has taken advantage of the excellent operating performance of the collider to record a large amount of useful data. This is now being used to check its correct operation and calibration. During this period, CMS has demonstrated the stability of the detectors' working conditions as well as the efficiency of the data analysis system, which sends data from the detector to analysis teams around the world, and this in spite of very rapidly changing beam conditions.

 

 

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