eRHIC, the proposed Electron Ion Collider at BNL using the RHIC collider complex.

Abstract:  The nuclear physics community strongly supports the construction of a future Electron Ion Collider (EIC) to study the origin of nuclear spin, the spatial distribution of gluons in the nucleon, how the gluon density saturates, and to enhance understanding of nuclear structure. Recently, two design studies with minimized technical risk have been carried out on the BNL version of the EIC called eRHIC which uses the RHIC collider and its injection complex. One of the studied solution is based on an Energy Recovery Linac (ERL) for electron acceleration. The second one includes an Electron Storage Ring (RR) in the RHIC tunnel. Both solutions support e-A collisions at center of mass energies of up to 140 GeV and promise to reach luminosities of up to 1034s-1cm-2. Luminosities in excess of 1033cm-1s-1 require for both designs a novel beam cooling technique called coherent electron cooling. The solution based on an electron storage ring has the advantage of requiring only proven technologies which implies minimum technical risk in the implementation of the design whereas several years of R&D is required to retire the risks of the ERL based design options. The decision has now been made to concentrate the eRHIC design effort in FY17 on the RR design to movie the design forward towards CD0 by then of FY18. The presentation will describe the RR design, the expected collider performance, the electron injector complex as well as the corresponding R&D program.