Design considerations for the linac system of the ESS

The proposed European spallation neutron source (ESS) will be the leading n eutron scattering research facility based on pulsed high intensity/high ene rgy proton beams. According to the present reference design, a linear accel erator produces 1.2 ms long H- beam pulses of 1.334 GeV with a repetition r ate of 50 Wt. The beam is accumulated in two rings. The stored beams are ex tracted in one turn resulting in a pulse of 1.3 mu s duration which is deli vered to one of the two liquid mercury target stations. Beams from two H- i on sources are pre-accelerated by radio frequency quadrupoles (RFQs), then combined to one beam of about 120 mA. After acceleration in a drift tube li nac (DTL) to 70 MeV a coupled cavity linac (CCL) accelerates the beam to th e final energy. The CCL can be realized in normal conducting or in supercon ducting (SC) version which is expected to result in a significant cost redu ction for investment and operation. (C) 2000 Elsevier Science B.V. All righ ts reserved.