Facility for studying spin dependence in pion production near threshold

We describe an experimental setup for the measurement of polarization observables in pion production near threshold. Experiments carried out with this facility use a polarized proton beam in the Indiana University Cooler storage ring, and an internal, polarized hydrogen target. The detector system measures energy, direction and velocity of multiple outgoing charged particles that are within a forward cone of about 32° opening angle. An array of scintillators also allows the detection of neutrons. In addition to the technical details of the apparatus, we describe the procedure for data acquisition, as well as some aspects of the analysis.