Fermilab, Batavia, Illinois, USA
NSCL, East Lansing, Michigan, USA
RRCAT, Indore (M.P.), India
The PIP-II program of upgrades proposed for the Fermilab accelerator complex, is centered around a 800 MeV, 2 mA CW SRF linac. A unique feature of the PIP-II linac is the capability to form a flexible bunch structure by removing a pre-programmed set of bunches from a long-pulse or CW 162.5 MHz train, coming from the RFQ, within the 2.1-MeV Medium Energy Beam Transport (MEBT) section. The MEBT chopping system consists of two travelling-wave kickers working in sync followed by a beam absorber. The prototype components of the chopping system, two design variants of the kickers and a 1/4-size absorber, have been installed in the PIP-II Injector Test (PIP2IT) accelerator and successfully tested with beam of up to 5 mA. In part, one of the kickers demonstrated a capability to create an aperiodic pulse sequence suitable for synchronous injection into the Booster while operating at 500 V and average switching frequency of 44 MHz during 0.55 ms bursts at 20 Hz. This report presents the design of the PIP-II MEBT chopping system and results of prototypes testing at PIP2IT.
Fermilab, Batavia, Illinois, USA
A second harmonic RF cavity which uses perpendicularly biased garnet for frequency tuning is currently being constructed for use in the Fermilab Booster. The cavity will operate at twice the fundamental RF frequency, from ~76 - 106 MHz, and will be turned on only during injection, and transition or extraction. Its main purpose is to reduce beam loss as required by Fermilab's Proton Improvement Plan (PIP). After three years of optimization and study, the cavity design has been finalized and all constituent parts have been received. We discuss the design aspects of the cavity and its associated systems, component testing, and status of the cavity construction.