Calculation of the electric field at the edge of the operation region of the Cathode Strip Chambers of the CMS ME1/1 station

Distortion of the electric field near the edge of the operation region of the Cathode Strip Chamber (CSC) of the first Muon Endcap Station (ME1/1) of the Compact Muon Solenoid (CMS) is studied. The distortions of the shape and the magnitude of the electric field that arise from the presence of the insulating frame, which supports the anode wire array, are investigated. The electric field calculation is done with the aid of the boundary elements method.