Magnetic Field Measurement of 2-m-Long Model of Beam Separation Dipole for the HL-LHC Upgrade

KEK has been developing a beam separation dipole magnet for the high luminosity large hadron collider upgrade. The magnet has a coil aperture of 150 mm and uses NbTi superconducting cable. A dipole magnetic field of 5.6 T is generated at 12 kA at 1.9 K to provide a field integral of 35 T·m. KEK has started the development of the first 2-m-long model magnet to evaluate the design and performance of the beam separation dipole magnet. The excitation test at 1.9 K of the first 2-m-long model magnet was performed from April to June 2016 at KEK. This paper presents the results of the magnetic field measurements of the first 2-m-long model magnet by a rotating coil probe.

I. Introduction

A major High Luminosity upgrade, of the superconducting magnet systems in the region of the beam collision point of the Large Hadron Collider at CERN is being planned for around 2024 (HL-LHC) [1] , [2]. The High Energy Accelerator Research Organization (KEK) has participated in the design study of the HL-LHC within the framework of the CERN-KEK collaboration. In the HL-LHC machine, the resistive D1 magnets will be replaced by superconducting dipole magnets with a larger coil aperture of 150 mm and a higher field integral of 35 T⋅m than those used at present. Until now, a series of conceptual design studies has been carried out at KEK with the support of CERN [3]– [7]. Following the design studies, the first 2-m-long model magnet has been developed to evaluate the performance [8], [9].