Study of spatial resolution properties of a glass RPC

A prototyping glass RPC with excellent signal-to-noise ratio was constructed and tested. Detection efficiencies for cosmic rays of about 95% were obtained for both avalanche and streamer modes of operation. A simple method to measure the signal charge profile is developed, which is consistent with other methods such as direct optical observation. A narrow profile for avalanche signal mode is obtained, which may lead to an intrinsic spatial resolution less than 1.0 mm FWHM. If a delay-line or charge division technique is used to determine the centroid of the signal charge distribution, it is important to reduce the electronics noise and the fluctuations of the delay-line (or resistor) units in order to reach the ultimate intrinsic position resolution.