Comparison of Cold Powering Performance of 2-m-Long Nb3Sn 11 T Model Magnets

For the upgrade of the LHC, two 15-m NbTi main dipole magnets are foreseen to be replaced by two 11 T 5.7-m-long Nb
₃
Sn dipoles each. A series of model magnets has been produced to verify the design choices that are important for the prototype and series production, focusing on mechanical aspects and protection studies. A fourth and a fifth 2-m single aperture models were produced, assembled, and tested. In this paper, the cold powering tests of the single aperture models SP104 and SP105 will be presented and the results will be compared with the previous models. Special attention will be given to the upper limit in magnet current due to quenches in the midplane turns.