Beamtest of nonirradiated and irradiated ATLAS SCT microstrip modules at KEK

Nonirradiated and irradiated ATLAS silicon microstrip barrel and endcap modules have been beamtested with 4-GeV/c pions. Pulse shapes confirmed the peaking time of the amplifier to be 22 ns with slight deterioration in the irradiated modules. Median charges saturated around 3.8 fC, both in the nonirradiated and the irradiated modules. Signal/noise ratios, using the noise estimates from the in-situ calibration, were >16 in the nonirradiated (>150 V) and >10 in the irradiated (>300 V) barrel modules. No excess common-mode noise was observed.