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Mon-Af-Po1.01-05 1 Design and Fabrication of the 1.9 K Magnet Test Fa- cility at BNL, and Test of the First 4 m-Long MQXF Coil J. Muratore, M. Anerella, P. Joshi, P. Kovach, A. Marone, P. Wanderer Abstract — The future high luminosity upgrade of the Large Had- vertical superconducting magnet test facility of the SMD at ron Collider (LHC) at CERN will include twenty 4.2 m-long BNL has been upgraded to perform testing in superfluid He at Nb 3 Sn high gradient quadrupole magnets which will be compo- 1.9 K and 1 bar, the operational condition at the LHC. This nents of the triplets for two LHC insertion regions. In order to has involved extensive modifications of the 40-year old, 4.5 K test these and four pre-production models, the vertical supercon- cryogenics plant and vertical test facility at the SMD. These ducting magnet test facility of the Superconducting Magnet Divi- upgrades include new piping, compressors, and other critical sion (SMD) at Brookhaven National Laboratory (BNL) has been upgraded to perform testing in superfluid He at 1.9 K and 1 bar, components; a new vertical test cryostat with a top plate and the operational condition at the LHC. This has involved extensive hanging fixture which can accept larger diameter and longer modification of the 4.5 K cryogenics plant, including piping, magnets, up to an actual length of 5 m; a 1.9 K heat exchang- compressors, and other upgraded components; a new vertical test er; a newly designed warm bore tube; and a lambda plate de- cryostat which can accept larger diameter magnets; a modern- signed with a novel sealing scheme to provide for both ized power supply system upgraded with IGBT switches and fast strength and minimum heat loss. In addition, the former short shutoff capability, and that can supply 24 kA to test high field Nb 3 Sn magnets; and completely new data acquisition, signal sample cable test facility 30 kA power supply has been up- analysis, and control software and hardware, allowing for fast, graded with an energy extraction system using IGBT switches high precision, large volume data collection. This paper reports and fast shutoff capability, and new high energy dump resis- on the design, assembly, and commissioning of this upgraded test tors, and has been reconfigured to supply 24 kA to test high facility, and presents results of the first magnet test performed. field Nb 3 Sn magnets. Index Terms — accelerator magnet, superconducting coils, We have also assembled completely new data acquisition, quench protection, test facilities signal analysis, and control software and hardware, allowing for faster, higher precision, and larger volume data collection. This paper describes the design, assembly, and commis- I. I NTRODUCTION sioning of the upgraded test facility, and reports on the first magnet test performed, on a mirror model, which consists of a he future high luminosity (HiLumi) upgrade of LHC at T single coil quadrant and an iron yoke which fills the space of CERN will include twenty 4.2 m-long Nb 3 Sn high gradi- the other three quadrants. The test facility and its upgrades can ent quadrupole magnets which will be components of the Q1 be discussed in four general areas: 1) cryogenics facility, and Q3 triplets for two insertion regions of the LHC. These 2) vertical test cryostat and magnet fixture, 3) power supply magnets, denoted as MQXFA, will be supplied by the US Ac- system with quench protection, and 4) data acquisition, con- celerator Upgrade Project (AUP), a collaboration of BNL, trol, and analysis hardware and software. Fermi National Accelerator Laboratory, and Lawrence Berke- ley National Laboratory. Each magnet will have four two- layer coils wound with 40-strand Nb 3 Sn Rutherford cable in TABLE I order to generate the high field gradients necessary for the REQUIRED OPERATIONAL PARAMETERS FOR MQXFA TESTS LHC HiLumi upgrade. Table I shows required operational pa- Coil inner aperture D = 150 mm rameters for these magnets, which include operating at cur- l = 4.2 m Coil magnetic length rents up to 17.89 kA, known as the ultimate current. More in- l = 4.523 m Coil actual length formation about the MQXFA magnets and the test require- l = 5 m (nom) Total magnet length ments can be found in [1], [2]. Operational temperature T = 1.9 K In order to test these and four pre-production models, the LHC nominal operating current (1.9 K) I nom = 16.470 kA LHC ultimate operating current (1.9 K) I ult = 17.890 kA This work was supported by the U.S. Department of Energy, Office of Sci- ence, Office of High Energy Physics, through the US LHC Accelerator Re- Conductor limit at 1.9 K I ss = 21.600 kA search Program and by the High Luminosity LHC project at CERN. The U.S. Conductor limit at 4.5 K I ss = 19.550 kA Government retains and the publisher, by accepting the article for publication, Magnet inductance (at 1.9 and 1 kA) L 1 = 40.9 mH acknowledges that the U.S. Government retains, a non-exclusive, paid-up, ir- revocable, world-wide license to publish or reproduce the published form of Magnet inductance (at 1.9 and I nom =16.5 kA) L 16.5 = 32.8 mH this manuscript, or allow others to do so, for U.S. Government purposes. Operating stored energy (at B nom , I nom ) E max = 4.5 MJ The authors are with the Superconducting Magnet Division, Brookhaven R D = 30, 37.5, 50, 75, 150 mΩ Dump resistor (energy extraction) options National Laboratory, Upton, NY 11973 USA (e-mail: Muratore@bnl.gov).