Performance of the Room Temperature Systems for Magnetic Field Measurements of the LHC Superconducting Magnets

Abstract

The LHC will be composed of 1232 horizontally curved, 15-meter long, superconducting dipole assemblies and 474 Short Straight Sections containing various types of quadrupoles. These magnets are manufactured by several European companies and half of them are currently produced. The field quality at room temperature is strictly monitored to guide and validate the assembly at different stages of the production in the industry. Dipoles and quadrupoles are measured with two different rotating coil systems. These "moles" travel inside the 50 mm aperture and accurately measure the field and gradient strength integrated over the length, the field direction and high order harmonics. We describe here these two systems, their performance and the experience gained through the two first years of operation. The field quality at room temperature is strictly monitored to guide and validate the assembly at different stages of the production in the industry. Dipoles and quadrupoles are measured with two different rotating coil systems. These "moles" travel inside the 50 mm aperture and accurately measure the field and gradient strength integrated over the length, the field direction and high order harmonics. We describe here these two systems, their performance and the experience gained through the two first years of operation.

LHC IR Upgrade Nb–Ti, 120-mm Aperture Model Quadrupole Test Results at 1.8 K

“…During cool-down the temperature difference between the top and bottom of the magnet was maintained at 180 K. The magnetic field was only measured at room temperature, revealing an error of a few units [11][12]. We will fully map at high current the field quality in the next test campaign.…”

Development of a rotating-coil scanner for superconducting accelerator magnets

“…The S rad n is calculated using the geometry of the coils and its arrangement in the probe. The field multipoles can be calculated from the measurements by (Russenschuck, 2010).…”

Magnet Design and Testing for the 250 MeV Injector of the SwissFEL at the Paul Scherrer Institute

“…Care was taken to the choice of the copper conductor by the selecting a size appropriate for the specifications but also common for most applications (i.e. 8 with a cooling channel of 5 mm in diameter, or ). The Paul Scherrer Institute has also the capability of winding small coils.…”

“…The second system consists of a flux integrating probe (mole) constructed by CERN (Geneva-Switzerland), on loan to the Paul Scherrer Institute since January 2009 [8]. The mole consists of 5 coils, mounted side by side, the central one being centered on the rotation axis.…”