Construction and Test of 3.6 m ${\hbox{Nb}}_{3}{\hbox{Sn}}$ Racetrack Coils for LARP

Development of high-performance Nb3Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets were made in order to check the fabrication steps for long Nb3Sn coils, that the changes in coil length that take place during reaction and cooldown are correctly accounted for in the quadrupole design, and the use of a long aluminum shell for the support structure. This paper reports the construction of the first long Nb3Sn magnet with racetrack coils 3.6 m long. The magnet reached a nominal "plateau" at 9596 A after five quenches. This is about 90% of the estimated conductor limit. The peak field in the coils at this current was 11 T.