Status of Slip Stacking at Fermilab Main Injector

To achieve an increase in proton intensity, the Fermilab Main Injector (MI) is using a stacking process called "slip stacking" [1]. The intensity will be doubled by injecting one train of bunches at a slightly lower energy, another at a slightly higher energy, then bringing them together for the final capture. Beam studies have been performed for this process and we have verified that, at least for low beam intensities, the stacking procedure works as expected [2]. For high intensity operation, an upgrade of the 4kW solid state drivers to 8kW was done during the last machine shut down, from August to November 2004. Slip stacking became operational in December 2004.