The Single Beam Dynamics Study at CESR 1

The described in [1] nonlinear eld components of CESR elements have been included in model structure. Then using program MAD [2] the single beam dynamics was explored. The calculated variation of betatron tunes versus orbit position and the excitation of the nonlinear betatron resonances found with tracking are in good agreement with measurements. The elements given the main contribution into tune variation as well as into the nonlinear coupling resonances excitation have been detected. Model Nonlinearities The CESR nonlinear eld components included in model have been described in [1]. The e ective nonlinearity of a element was represented by thin multipole placed in structure next after it. In the case of quads, sextupoles and horizontal separators the strength of these multipoles was proportional to the main element strength. The nonlinearity of vertical steerings was incorporeted into mode as the following. First, using the save set data and vertical steerings calibration, its de ection angles have been calculated, then its nonlinearities were determined according to magnetic measurements. The Work supported by the National Science Foundation On leave from BINP, Novosibirsk