E1039/SpinQuest Polarized Drell-Yan Experiment at Fermilab

E1039, now named SpinQuest, is not only the successor to a series of unpolarized, fixed-target SeaQuest experiments but also the first transversally-polarized Drell-Yan experiment at Fermilab. SpinQuest data-taking begins this coming Fall 2019. In SpinQuest, a transversely-polarized NH3 or ND3 target is employed with the unpolarized, 120-GeV proton beam split from Fermilab main injector, to obtain measurements of the transverse single spin asymmetry, aka the Sivers asymmetry, without the need to account for fragmentation effects.  If we observe a non-zero Sivers asymmetry, then the sea quarks' orbital angular momentum (OAM) contribution to the spin inside the nucleon must also be non-zero.  A perceptible, non-vanishing OAM from the sea quarks would help to uncover the origin of the proton spin. Since the beginning of the SpinQuest commissioning in Fall 2018, we've implemented a wide range of changes on various systems such as the target, beam-line monitoring instrumentation, spectrometer, trigger, data acquisition, online event display, slow control, offline tracking reconstruction, simulation and software framework. In this talk, we will report on the current status of SpinQuest.