Development of septum quadrupole prototype for DESY upgrading luminosity

In the frames of collaboration between IHEP and DESY the prototype of the septum quadrupole based on existing in DESY QC quadrupole has been developed, manufactured and tested in IHEP. The main goal of this R&D was to choose a magnet configuration including a septum plate, a septum notch for the electron beam and trim-coils matching to specify and further apply in a full-scale magnet. The ingenious magnetic correcting system allowing one to get a high field quality of a few units 10−4 inside the operating range of the proton beam has been suggested. A chosen optimal geometry of the reflecting iron plate provides a required field magnitude along the electron beam path as well. The computer simulation of various geometric distortions influencing on the field quality has been performed and, as a result, the tolerances to the production accuracy have been formulated. These analyses displayed very strict requirements to both the manufacturing accuracy and magnetic properties of the septum plate steel.