Treatment of wiggler and undulator field errors in tracking codes

Wigglers and undulators produce intense synchrotron radiation, used for dedicated experiments or to control beam dimensions. To obtain tolerance criteria for wiggler and undulator field errors, this paper presents a treatment which takes into account the special geometry of wigglers and undulators and the undulating beam trajectory. This is done by creating a nonlinear transfer map of the beam motion through the (measured) magnetic fields. To verify the method, results of tracking calculations using data from magnetic field measurements are compared with dedicated experiments performed at DESY´s synchrotron radiation source DORIS III. Measurements of tune shifts with closed orbit amplitudes and of the dynamic acceptance agree with the results of the tracking