FACET TOLERANCES FOR STATIC AND DYNAMIC MISALIGNMENT

The Facility for Advanced Accelerator and Experimental Tests (FACET) at the SLAC National Accelerator Laboratory is designed to deliver a beam with a transverse spot size on the order of 10 µm × 10 µm in a new beamline constructed at the two kilometer point of the SLAC linac. Commissioning the beamline requires mitigating alignment errors and their effects, which can be significant and result in spot sizes orders of magnitude larger. Sextupole and quadrupole alignment errors in particular can introduce errors in focusing, steering, and dispersion which can result in spot size growth, beta mismatch, and waist movement. Alignment errors due to static misalignments, mechanical jitter, energy jitter, and other physical processes can be analyzed to determine the level of accuracy and precision that the beamline requires. It is important to recognize these effects and their tolerances in order to deliver a beam as designed.