  The ESS Neutrino Super-Beam (ESSnuSB) is a proposed long-baseline neutrino
oscillation experiment, performed with a high-intensity neutrino beam, to be
developed as an extension to the European Spallation Source proton linac
currently under construction in Lund, Sweden. The neutrinos would be detected
with the near and far detectors of the experiment, the former within several
hundred meters of the neutrino production point and the latter within several
hundred kilometers. The far detector will consist of a megaton-scale
water-Cherenkov detector, and the near detector will consist of a kiloton-scale
water-Cherenkov detector in combination with a fine-grained tracking detector
and an emulsion detector. The purpose of the near detector is to constrain the
flux of the neutrino beam as well as to extract the electron-neutrino
interaction cross-section in water, which requires high-performance energy
reconstruction and particle flavor identification techniques. These
measurements are crucial for the neutrino oscillation measurements that will be
conducted using the far detector.
  Year 2021 sees the finalization of the conceptual design of the near detector
after a thorough evaluation of the performance of a number of different design
options, and a characterization of the neutrino reconstruction and flavor
identification performances. In this talk we report on thesestudies.
