NUMERICAL METHODS FOR THE ORBIT CONTROL AT THE KEK 12 GEV-PS

At the KEK 12GeV-PS main ring (PS-MR), when the least square method is applied to correct whole beam orbit all at once, it remains unacceptable beam loss and it is necessary to adjust the local positions of the beam orbit by hands with the beam loss monitors until the beam loss is suppressed under an acceptable level. However, the orbit generated by this way doesn't always satisfy the minimum-loss condition. In this paper, a new method is proposed. It focuses a fact that the beam loss distribution depends on the shape of the beam orbit, and formulates this relationship to a functional approximation by using a neural network algorithm. Then, solving an optimization problem for generated network system, data of the beam shape which is more suitable for the beam loss of the accelerator can be obtained. The description of the system construction and experimental results are presented.