Design of the SNS MEBT

The medium-energy beam transport (MEBT) of the Spallation Neutron Source (SNS) is described. It transports a 2.5 MeV, 52 mA H beam through a series of 14 quadrupoles and four 402.5 MHz rebuncher cavities from the RFQ to the DTL. A 10-nsec rise/falltime traveling wave chopper/antichopper is incorporated in the transport lattice. Special emphasis is given to emittance preservation, which requires an unusually compact mechanical design. Details of the beam dynamics and mechanical design will be given.