The Accumulator of the ESSnuSB for neutrino production

The European Spallation Source (ESS) is a research center based on the world's most powerful neutron source currently under construction in Lund, Sweden. 2.0 GeV, 2.86 ms long proton pulses at 14 Hz are produced for the spallation facility (5MW on target). The possibility to pulse the linac at higher frequency to deliver, in parallel with the spallation neutron production, a very intense, cost effective, high performance neutrino beam. Short pulses on the target require an accumulator ring. The optimization of the accumulator lattice to store these high intensity beams from the linac (1.1x10¹⁵ protons per pulse) has to take into account the space available on the ESS site, transport of H⁻ beams (charge exchange injection), radiation and shielding needs. Space must be available in the ring for collimation and an RF system for the extraction gap and loss control. We present the status of the accumulator for ESS neutrino facility.