Equivalent Electrical Model for ICR detection. (Is = induced image current, Ct = Cc + Ccw, Cc = intrinsic Cell capacitance, Ccw is the connecting wire capacitance, CFET = preamplifier input capacitance, Rb = preamplifier input bias resistance, iRb = Johnson noise due to Rb, in = preamplifier equivalent input noise current, en = preamplifier equivalent input noise voltage)