OPERATIONAL EXPERIENCE INTEGRATING SLOW AND FAST ORBIT FEEDBACKS AT THE ALS∗

A fast global orbit feedback system has been imple-mented at the ALS and is being used during user opera-tion since this year. The system has two main purposes. The first is to meet the demands of some users for even im-proved (submicron) short term orbit stability. The second is to enable the use of more sophisticated insertion device compensation schemes (e.g. tune, beta-beating, coupling) for fast moving insertion devices like elliptically polarizing undulators, without deteriorating the orbit stability. The ex-perience of routine user operation with the fast orbit feed-back will be presented, as well as the overall feedback per-formance and how the integration issues with the already existing slow orbit feedback were solved