Beam based alignment of the SLC final focus superconducting final triplets

The strong demagnification inherent in final focus systems requires very high gradients for the final quadrupoles. Alignment of these magnets is critical in order to minimize the dispersion at the interaction point and backgrounds in the detector due to synchrotron radiation. Reported here is a technique for aligning the final quadrupoles with respect to the beam centroid, which makes use of measurements of the beam position downstream of the quadrupoles when their fields are varied. Results for the SLC final focus final superconducting triplets are presented, where a resolution of <20 μm is achieved