Performance of the Intermediate Si tracker at sPHENIX

sPHENIX is a second-generation RHIC experiment designed to study the quark-gluon plasma and the spin structure of the proton. The Intermediate Silicon Tracker (INTT), a two-layer silicon strip detector, provides precise beam crossing separation and vertex reconstruction using tracklets. In 2024, sPHENIX recorded √sNN = 200 GeV collisions, where the INTT operated in triggered mode for Au+Au data and in streaming mode for p + p data. We report the INTT performance, including crossing separation, z-vertex reconstruction, and the first physics result: charged hadron multiplicity in Au+Au collisions, consistent with previous RHIC measurements.