A mStrip gas chamber with true two-dimensional and pixel read-out

Summary form only. A true 2-D μ-strip gas chamber has been constructed and successfully tested. This detector has an effective substrate thickness of less than 2 μm. An ion-implanted oxide layer of 1.8-μm thickness provides the necessary insulation between the front and back plane and permits collection on the back electrodes of a large fraction of the induced charge. The back electrode signal is used to measure the coordinate along the anode strips (X-Y readout) or to provide true space points (pixel read-out). Very good imaging capabilities have been obtained in both cases. A flux of 10⁷ particles/mm²-s has been measured without significant gain loss. No charging effect has been observed after three days of continuous running at a flux of 10⁴ particles/mm²-s, while a 15% gain loss, probably due to aging effects, has been measured after collection on the strips of a charge corresponding to more than six years of running at the design luminosity of the Large Hadron Collider, LHC, at 50 cm from the beam axis