HOM Absorber Design for eRHIC ERL Cavities

The Office of Nuclear Physics long range plans include allocation of resources to develop technology for a polarized electron-ion collider- Brookhaven National Lab proposes two options for eRHIC, a ring-ring design and alternatively an Energy Recovery Linac design- A high current ERL design would provide for significant upgrade in luminosity- A high current ERL is also required for ion cooling- High power higher order modes develop within the multi-cell SRF cavities-These modes must be absorbed to minimize their effects on the beam- To preserve the beam and its characteristics the multi-cell SRF cavities require higher order mode outcoupling and absorption- A sister proposal will focus on the outcouplers, while this proposal focuses on the HOM absorber module- A broadband absorber, SiC, will be evaluated with RF models- The absorber design will be applicable to many waveguide shapes-