Teresa Martinez

MCBXF magnets are orbit correctors for the High-Luminosity (HL) Large Hadron Collider (LHC) upgrade. The magnet design consists of two nested dipoles, with an aperture of 150 mm, which is described elsewhere. The magnets have been designed in two physical lengths, namely of 2.5 m (MCBXFA) and 1.5 m (MCBXFB), with the same cross section. The series production of the magnets consists of 5 long and 10 short magnets. The component production is being carried out at CIEMAT and magnet assembly is made at CERN. This paper summarizes the results of the magnetic measurements of the short magnets produced so far, including warm magnetic measurements. The first magnets featured repetitive results regarding field quality. Afterwards, some of the magnets showed a shift of the main harmonics. After careful analysis of the fabrication steps, it was found out that the impregnation mold assembly strategy impacted on the coil dimensions. The shimming plan was tuned to deal with this feature, and the field quality was enhanced accordingly.

MCBXF magnets are orbit nested correctors for the HL-LHC project, an upgrade of the Large Hadron Collider (LHC). The magnet design consists of two nested dipoles, with an aperture of 150 mm. The magnets have been designed in two physical lengths, namely of 2.5 m (MCBXFA) and 1.5 m (MCBXFB), with the same cross section according to the necessities. Two prototypes and the first series magnet of the short version were manufactured at CIEMAT and assembled at CERN. The series production of the rest of the series magnets, 6 long (MCBXFA) and 11 short (MCBXFB) magnets, is being carried out at the premises of the company Elytt Energy. In this paper the powering test results of the first batch of MCBXFB magnets produced in the industry are presented, including both the results of training and magnetic measurements. An endurance test was made to check the reliability of the magnets after a large number of powering cycles and torque inversions.

MCBXFA magnets are long orbit nested correctors for the high luminosity upgrade of the LHC. They are the 2.5 m long version of the short orbit correctors MCBXFB, sharing the same cross-section. The components of the first prototype MCBXFAP1 have been produced by CIEMAT. The magnet was assembled in collaboration with CERN at its facilities (927 laboratory). This article depicts in first place the assembly steps of MCBXFAP1, which required the fabrication of custom tooling and faced some difficulties, mainly caused by the additional length compared to the short corrector. Shimming plan and magnet length adjustment are reported. After that, the powering test results at the CERN test station (SM-18) and the magnetic measurements campaign are presented.

2.5-m-long nested orbit correctors (so-called MCBXFA) are necessary for the upgrade of LHC, in the framework of HL-LHC project. These magnets provide 2.1 T in vertical and horizontal direction and they share the same cross-section of their shorter version MCBXFB, for which two prototypes and the first two series magnets have been manufactured and tested. In this paper we first present the specific aspects of MCBXFA magnet design: (i) field quality in the different powering scenarios, and (ii) mechanical analysis, with special attention to torque under combined operation. We then overview the manufacturing techniques, which are very similar to those used for MCBXFB, pointing out some difficulties that have arisen during the coil vacuum impregnation. The components of the prototype magnet are being produced by CIEMAT and the magnet will be assembled at CERN facilities.

MCBXF magnets are nested orbit combined correctors for the upgrade of the LHC. Two prototypes and the first series magnet were manufactured at CIEMAT and assembled at CERN, in the framework of the HL-LHC project. A fine tuning of the inner dipole design was introduced in the first series magnet to improve the mechanical support at the inner dipole coil ends, with a significant performance improvement. The contract to supply the rest of the series magnets, 6 long (MCBXFA) and 11 short (MCBXFB) magnets, has been awarded to the company Elytt Energy. This paper depicts the manufacturing and powering test results of the first MCBXFB magnet produced in Elytt Energy. In order to mitigate risks prior to the assembly of this magnet, a new reassembly of the second prototype magnet with shorter inner coils, according to the above-mentioned fine tuning, has been tested. The results of this powering test are also detailed.

MCBXFB magnets are nested orbit combined correctors for the upgrade of the LHC. The first three magnets were manufactured at CIEMAT and assembled at CERN, in the framework of the HL-LHC project. The power tests performed on the first prototype showed that the behavior when the dipoles were individually powered was excellent, but the training to reach nominal currents in combined operation was very long. Memory was lost when the torque direction changed. A similar behavior was found in the first power test of the second prototype described elsewhere. The origin of the problem has been identified as insufficient mechanical support at the inner dipole coil ends. This paper depicts the results of the power test after the reassembly of the second magnet with increased prestress on the coils. Shimming plan is discussed. Furthermore, a fine tuning of the inner dipole design has been introduced in the third magnet. The results of the power tests on that magnet show a significant performance improvement.