The ESS accelerator high level requirements are to provide a 2.86 ms long proton pulse at 2 GeV at repetition rate of 14 Hz. This represents 5 MW of average beam power with a 4% duty cycle on target.
The ion source produces a proton beam that is transported through a Low Energy Beam Transport (LEBT) section to the Radio Frequency Quadrupole (RFQ) where it is bunched and accelerated up to 3.6 MeV. In the Medium Energy Beam Transport (MEBT) section the transverse and longitudinal beam characteristics are diagnosed and optimized for further acceleration in the Drift Tube Linac (DTL). The first superconducting section consists of 26 double-spoke cavities (SPK) with a geometric beta value of 0.50. The spoke-cavities are followed by 36 Medium Beta Linac (MBL) cavities with β = 0.67 and 84 High Beta Linac (HBL) elliptical cavities, with β = 0.86. After acceleration the beam is transported to the target through the High Energy Beam Transport (HEBT) section.