A detector system for hyperon production at the COSY time-of-flight spectrometer

In an experiment at the external COSY beam associated strangeness production will be investigated [1] by measuring total and differential cross sections as well as the polarization of the produced hyperons by means of an almost 4π time-of-flight spectrometer. In a first step we will concentrate on the reaction pp → KΛp. The apparatus will consist of an inner arrangement as start detector and highly granulated scintillator hodoscopes as stop detector. Both parts give information on multiplicity and allow to identify the interesting reaction by means of the delayed charged decay of the Λ. Moreover the tracks of all prompt and delayed reaction products can be reconstructed with high precision. The detector allows the momentum measurement by time-of-flight. To get all this information the inner detector is composed of tiny granulated plastic scintillator detectors, silicon microstrip devices and a scintillating fibre hodoscope. The outer detector barrel with a diameter of about 3m and a length of about 7.5m will consist of three layers of plastic scintillator slabs, two of them bended in helix form. The status of the experiment will be presented. Moreover the results of test measurements for the different detector components will be discussed together with Monte Carlo calculations.