ESSnuSB: A New Facility Concept for the Production of Very Intense Neutrino Beams in Europe

Abstract

A new project for the production of a very intense neutrino beam has arisen to enable the discovery of leptonic CP violation and neutrino mass hierarchy. This facility will use the proton linac of the European Spallation Source (ESS) in Lund to deliver the neutrino super beam. The ESS linac is expected to be fully operational at 5 MW power by 2022, producing 2 GeV and 2.86 ms long proton pulses at a rate of 14 Hz. An upgrade of the mean power to 10 MW and a frequency of 28 Hz, in which half is for the neutron beam, is necessary for the production of the neutrino beam. The primary proton beam-line completing the linac will consist of switchyards and accumulator rings. The secondary beam- line producing neutrinos will consist of a four-horn/target station, decay tunnel and beam dump. To detect the produced neutrinos a far megaton scale Water Cherenkov detector will be placed at a baseline of about 500 km in one of the existing mines in Sweden. The elements of the primary and secondary beam-lines and all the possible scenarios impacting the design of the ESSνSB facility as well as the safety issues due to the high irradiation produced are presented and discussed in this paper.