Pbar deceleration in the Fermilab Main Injector: tune-up studies with proton beam

In this report we present the results of beam dynamics simulations as well as experiments with protons for deceleration from 150 GeV to 8.9 GeV in the Fermilab Main Injector (MI). The simulations are carried out on two different deceleration schemes: deceleration with a fast recovery MI cycle and with a slow recovery cycle. As a proof of principle we have carried out the first successful deceleration using proton beam in the Main Injector from the Tevatron extraction energy of 150 GeV to the Recycler injection energy of 8.9 GeV.