Design of a superconducting linac cavity for high-current energy recovery linac operation

The RHIC electron cooler as well as other applications (such as a linac-ring version of eRHIC) requires a very high average current CW electron linac in an energy recovery mode. In this paper we present the design of a 5-cell superconducting linac cavity for velocity of light particles. This cavity will operate at 703.75 MHz with a large beam pipe aperture of 19 cm diameter and ferrite HOM absorbers in the beam pipe, in addition to the conventional HOM couplers for low frequency HOMs. We will report the design of the cavity geometry using the BuildCavity and Superfish codes, loss factor simulations with ABCI, detailed HOM simulations with MAFIA (with and without the ferrite absorbers) and beam breakup simulations using the code TDBBU.