Effects of errors on the dynamic aperture of the Advanced Photon Source storage ring

The individual tolerance limits for alignment errors and magnet fabrication errors in the 7-GeV Advanced Photon Source storage ring are determined by computer-simulated tracking. Limits are established for dipole strength and roll errors, quadrupole strength and alignment errors, sextupole strength and alignment errors, as well as higher order multipole strengths in dipole and quadrupole magnets. The effects of girder misalignments on the dynamic aperture are also studied. Computer simulations are obtained with the tracking program RACETRACK, with errors introduced from a user-defined Gaussian distribution, truncated at {plus minus}5 standard deviation units. For each error, the average and rms spread of the stable amplitudes are determined for ten distinct machines, defined as ten different seeds to the random distribution, and for five distinct initial directions of the tracking particle. 4 refs., 4 figs., 1 tab

Effects of construction and alignment errors on the orbit functions of the advanced photon source storage ring

The orbit functions for the Advanced Photon Source Storage Ring have been studied using the simulation code RACETRACK. Non-linear elements are substituted into the storage ring lattice to simulate the effects of construction and alignment errors in the quadrupole, dipole, and sextupole magnets. The effects of these errors on the orbit distortion, dispersion, and beta functions are then graphically analyzed to show the rms spread of the functions across several machines. The studies show that the most significant error is displacement of the quadrupole magnets. Further studies using a 3 bump correction routine show that these errors can be corrected to acceptable levels. 1 ref., 10 figs., 1 tab