Performances of keystone geometry micro-strip gas chambers

The performances of micro-strip gas chamber detectors with CF4 counting gas have been tested with a 241Am α source. The behaviour of the gain as a function of gas pressure, the dependence of the energy resolution on gas pressure and anode voltage, and the gain variation along the strip length due to the keystone geometry of the micro-strip pads are reported. An empirical response function to describe such a position dependence of the gain is proposed.