• E. Schibler, J.-C. Ianigro
  IN2P3 IPNL, Villeurbanne
• J. Morales, N. Redon
  UCBL, Villeurbanne
• L. Perrot
  IPN, Orsay

The driver accelerator of the Spiral2 facility will deliver deuteron (40MeV) and proton (33MeV) beams with current up to 5mA and heavy ion (14.5MeV/n) beams up to 1mA. At the very end of the LINAC, the main Beam Stop will have to withstand a peak power of 200kW for deuterons, with an associated power density from 120W/mm2 to more than 700W/mm2. These challenging specifications impose the design of a new high efficiency Beam Stop that has been nicknamed SAFARI (French acronym of Optimized Beam Stop Device for High Intensity Beams). From the beam characteristics and activation constraints, we proposed and developed a complete design. We will present this original design and the different studies and optimizations which have been done: The Beam Stop shape marries to the beam characteristics in order to smooth for the best power density and improve thermo-mechanical behaviour under nominal and critical beams. Cooling system is directly machined from Beam Stop blocks. Optimization by various fluid studies and calculations led us to a new high efficiency counter-current water cooling system. We then compare calculated behaviour with first results obtained on our recent functional mock-up