The STAR Forward GEM Tracker

The STAR collaboration is preparing a forward tracking detector upgrade, the Forward GEM Tracker (FGT), to provide fundamental studies of the proton spin structure and dynamics in high-energy polarized proton–proton collisions at RHIC at BNL. The FGT is based on triple-GEM technology employing the industrial production of GEM foils by Tech-Etch Inc. and a laser-etched two-dimensional readout board manufactured by Compunetics Inc. The FGT project has completed an extensive R&D program of industrially produced GEM foils at Tech-Etch Inc. in comparison to GEM foils produced at CERN based on optical measurements and 55Fe source and testbeam measurements of a triple-GEM prototype detector using 10 × 10 cm 2 GEM foils. The FGT project requires large GEM foils which are currently being tested.