Analogue feedforward for SOLEIL electromagnetic insertion devices

Now that the machine and beamlines are in operation, new requirements have been identified. On the machine, a significant effort is under way to improve beam orbit stability. Among the sources of noise which perturb the electron beam, the effect of the undulators' transient electromagnetic fields has been identified. On beamlines using electromagnetic insertion devices, fast variation of the electromagnetic field is required. In order to improve this performance, a new implementation of the control system for the electromagnetic insertion devices (HU256, HU640 and EMPHU) was designed. This new control is based on a set of boards developed at SOLEIL, called "SPI BOARD PACKAGE".