• D.C. Plostinar
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

Future projects like a neutrino factory or an advanced spallation neutron source require high power proton accelerators capable of producing beams in the multi-MW range. The quality of the beam delivered to the target is very much dictated by the accelerator front end and by the lower energy linac. Prompted by the Front End Test Stand (FETS) under construction at Rutherford Appleton Laboratory (RAL), a new 800 MeV H^- linac is being considered as part of a possible MW upgrade for ISIS. Preliminary simulations of high intensity beam dynamics and beam transport in the new linac suggest that a re-evaluation of the front end Medium Energy Beam Transport (MEBT) line is necessary. In this paper different optical designs for the 3 MeV MEBT line are presented and their impact on the subsequent Drift Tube Linac (DTL) section is being analysed.