Cold Test Results of the LARP HQ Nb 3 Sn Quadrupole Magnet at 1 . 9 K

The HQ magnet is a 120 mm aperture, 1-meter-long Nb3Sn quadrupole developed by the LARP collaboration in support of the High-Luminosity LHC project. Several tests were performed at LBNL in 2010-2011 achieving a maximum gradient of 170 T/m at 4.4 K. As a next step in the program, the latest model (HQ01e) was sent to CERN for testing at 1.9 K. As part of this test campaign, the magnet training has been done up to a maximum current of 16.2 kA corresponding to 85 % of the short sample limit. The ramp rate dependence of the quench current is also identified. The efficiency of the quench heaters is then studied at 4.2 K and at 1.9 K. The analyses of the magnet resistance evolution during fast current discharge showed evidence of quench whereas high energy quenches have been successfully achieved and sustained with no