EVALUATION OF BEAM POSITION MONITORS IN THE NONLINEAR REGIME

We present an algorithm for processing BPM signals and extracting orbit and betatron phase advance that is valid for large closed orbit distortions. We calculate the BPM button response using Green's reciprocity theorem and numerical solution of Laplace's equation in two dimensions. The dif- ference between the calculated signals and the measured signals is minimized on the fly to to yield bunch position. We extend this technique for calculating the betatron phase advance.