Setup and beam-test of a TOF system as kaon tagger

At the Mainz Microtron MAMI experiments on the decay-pion spectroscopy of electro-produced Λ-hypernuclei are being prepared by the A1-Collaboration. The detection of associated kaons at very forward angles with respect to the 1.5-GeV electron beam will be used to tag the strangeness production. The kaon detection in the Kaos spectrometer requires a high level of background suppression. For the separation between kaons and pions via the time-of-flight method a new scintillator wall was constructed, consisting of 30 paddles coupled at both ends to fast PMTs. Together with a second scintillator wall, placed close to the focal-plane of the spectrometer, it is forming a single-arm TOF system in the momentum range ∝600 MeV/c. The status of the preparations for the hypernuclei experiments and results from a beam-test are presented.