Lifetime measurement of pi^+pi^- atoms to test low energy QCD predictions

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The aim of this project is to carry out the PS212 experiment (DIRAC) AT CERN PS.The objective of this ecperiment is to test the prediction of the non-perturbative QCD on the pi^+pi^- interaction.The construction of a new dedicated beamline was started in the fall of 1997. The magnetic spectrometer and the detectors are set up before the fall of 1998 when the test beam will be provided.In this project, we performed the construction and the final test of the detectors related to the second-level trigger, which are the responsibility of the Japanese Group, namely the Scifi hodoscope s, the dE/dx counters, and the peak-sensing circuits for the read-out. The beam hodoscopes using Scifi together with the peak-sensing circuits are proven to show the expected performance (detection efficiency, spatial and time resolution).In parallel, we designed a logic circuit which produces the trigger signal, built a prototype, and tested using the real beam. The real-size model to be used in the experiment is under construction.In addition, we've started the study of a silicon microstrip dE/dx counter to be used in place of the current dE/dx counter made with plastic scintillation counter.