An active target with plastic scintillating fibers has been constructed. This active target served as a production target of hyperons as well as a scattering target, and worked as a 4/spl ...pi/-detector for charged particles. This system is designed for measurement of hyperon-proton scattering for the hyperon momenta of several hundred MeV/c. A spectrometer system for the incident beam and outgoing particles of the hyperon production reaction is linked with this target-detector in order to provide triggers for the imaging device of this detector system. The decay constant of the /spl Sigma/ hyperon has been evaluated.
