RPC approved plots

Plot 1 Y (cm) X (cm) Single gap working region 20 40 Plot 1 RPC detector efficiency vs impact point measured extrapolating the DT segment on the RPC chamber. The lower efficiency points in step of 10 x 10 cm2 are due to the dead regions induced by spacers. The efficiency reduction is more visible for y coordinate around 55 cm where, due to the chamber construction, the RPC works in single gap.

Plot 2 PRELIMINARY Preliminary maximum efficiency distribution for the RPCs of three wheels of the barrel. The efficiency is measured extrapolating the DT segment on the RPC plane and looking at fired strips in a small region around the impact point. The measurement is repeated at different RPC working voltage and the maximum RPC efficiency is obtained by a fit to the efficiency vs High Voltage trend. The tail in the distribution is due to problematic chambers working in single gap mode or affected by swapped cables in the readout that have been fixed during the shut down. Systematic effects due to the fact that the distribution is obtained with cosmic muons and not with collision muons are under investigation, moreover no fiducial regions are selected to remove the edge of the RPCs.