Measurement and reduction of quadrupole injection oscillations in the Fermilab Antiproton Accumulator

We have utilized a quadrupole pickup in the Fermilab Antiproton Accumulator to reduce quadrupole injection oscillations of 8.9-GeV reverse protons injected from the Main Ring onto the Accumulator extraction orbit. Quadrupole oscillations of the injected beam at (2q-1)f₀ due to lattice-function mismatch between the beam transfer line and the Accumulator were measured by the pickup. Minimization was accomplished by varying the strength of quadrupoles in the beamline. Comparison of the quadrupole oscillation data with a beamline model allowed empirical estimation of the matching lattice functions of the line