CERN Accelerating science

Article
Title	Test Results for LHC Insertion Region Dipole Magnets
Author(s)	Muratore, Joseph F ; Anerella, Michael ; Cozzolino, John P ; Ganetis, George ; Ghosh, Arup ; Gupta, Ramesh C ; Harrison, Michael ; Kumar-Jain, Animesh ; Marone, Andrew ; Richard-Plate, Stephen ; Schmalzle, Jesse D ; Thomas, Richard A ; Wanderer, Peter ; Willen, Erich ; Wu, Kuo-Chen
Affiliation	(BNL, Upton, Long Island, New York)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.3106
Subject category	Accelerators and Storage Rings
Abstract	The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has made 20 insertion region dipoles for the Large Hadron Collider (LHC) at CERN. These 9.45 m-long, 8 cm aperture magnets have the same coil design as the arc dipoles now operating in the Relativistic Heavy Ion Collider (RHIC) at BNL and are of single aperture, twin aperture, and double cold mass configurations. They produce fields up to 3.8 T for operation at 7.56 TeV. Eighteen of these magnets have been tested at 4.5 K using either forced flow supercritical helium or liquid helium. The testing was especially important for the twin aperture models, which have the most challenging design. In these, the dipole fields in both apertures point in the same direction, unlike LHC arc dipoles. This paper reports on the results of these tests, including spontaneous quench performance, verification of quench protection heater operation, and magnetic field quality. Magnetic field measurements were done at 4.5K and at room temperature, and warm-cold correlations have been determined. Some dynamic measurements to study the effect of time decay and snapback at injection were also done, using a fast rotating coil.