BNL, Upton, Long Island, New York, USA
RHIC will be run at low ion beam center-of-mass energies of 7.7 - 20 GeV/nucleon, much lower than the typical operations at 100 GeV/nucleon. The primary motivation is to explore the existence and location of the critical point on the QCD phase diagram. An electron accelerator is being constructed to provide Low Energy RHIC electron Cooling (LEReC) to cool both the blue & yellow RHIC ion beams by co-propagating a 10 - 50 mA electron beam of 1.6 - 2.6 MeV. This cooling facility will include a 400 keV DC gun, SRF booster cavity and a beam transport with multiple phase adjusting RF cavities to bring the beam to one ring to allow electron-ion co-propagation for ~21 m, then through a 180° U-turn electron transport so that the same electron beam can similarly cool the other counter-rotating ion beam, and finally to a beam dump. The injector commissioning is planned to start in early 2017 and full LEReC commissioning planned to start in early 2018. The instrumentation systems that will be described include current transformers, BPMs, profile monitors, multi-slit and single slit scanning emittance stations, time-of-flight and magnetic energy measurements, and beam halo & loss monitors.
