2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/202874Two cylindrical forward TPC detectors are described which were constructed to extend the phase space coverage of the STAR experiment to the region 2.5 < |η| < 4.0. For optimal use of the available space and in order to cope with the high track density of central Au+Au collisions at RHIC, a novel design was developed using radial drift in a low diffusion gas. From prototype measurements a 2-track resolution of 1-2 mm is expected.10 pages, including 9 figures and 1 table; to appear in a special NIM volume dedicated to the accelerator and detectors at RHICNuclear ExperimentInstrumentation and Detectorstext