en-usStatus of the ESSnuSB Accumulator Design

The 2.0 GeV, 5 MW proton linac for the European Spallation Source, ESS, will have the capacity to accelerate additional pulses and send them to a neutrino target, providing an excellent opportunity to produce an unprecedented high performance neutrino beam, the ESS neutrino Super Beam, ESSnuSB, to measure, with precision, the CP violating phase at the 2nd oscillation maximum. In order to comply with the acceptance of the target and horn systems that will form the neutrino super beam, the long pulses from the linac must be compressed by about three orders of magnitude with minimal particle loss, something that will be achieved through multi-turn charge-exchange injection in an accumulator ring. This ring will accommodate over 2·10¹⁴ protons, which means that several design challenges are encountered. Strong space charge forces, low-loss injection with phase space painting, efficient collimation, a reliable charge stripping system, and e-p instabilities are some of the important aspects central to the design work. This paper presents the status of the accumulator ring design, with multi-particle simulations of the injections procedure.