Test Results and Analysis of LQS03 Third Long $ \hbox{Nb}_{3}\hbox{Sn}$ Quadrupole by LARP

With the first test of LQS03, the long quadrupole (LQ) R&D by LARP (the US LHC Accelerator Research Program, a collaboration of BNL, FNAL, LBNL, and SLAC) is approaching conclusion. LQS03 is the third 3.7-m-long quadrupole, with 90 mm aperture, using a full new set of
$\hbox{Nb}_{3}\hbox{Sn}$
coils. The LQS03 coils were made using 108/127 RRP strand (with 108
$\hbox{Nb}_{3}\hbox{Sn}$
subelements) produced by Oxford Superconducting Technology, whereas both previous models used 54/61 RRP strand (with 54 larger
$\hbox{Nb}_{3} \hbox{Sn}$
subelements). In this paper, LQS03 test results are presented and discussed. The test results are also compared with the performances of the previous models. Observations are made for the future use of
$\hbox{Nb}_{3}\hbox{Sn}$
in accelerator magnets.