MEASUREMENTS OF SEXTUPOLE DECAY AND SNAPBACK IN TEVATRON DIPOLE MAGNETS

To help optimize the performance of the Fermilab Tevatron accelerator in Collider Run II, we have undertaken a systematic study of the drift and subsequent snapback of dipole magnet harmonics. The study has mostly focused on the dynamic behavior of the normal sextupole component, b2, as measured on a sample of spare Tevatron dipoles at the Fermilab Magnet Test Facility. We measured the dependence of the decay amplitude and the snapback time on Tevatron ramp parameters and magnet operational history. A series of beam studies was also performed (1). This paper summarizes the magnetic measurement results and concludes with proposals for an optimization of the b2 correction scheme which is derived from these measurements.