Status Report on the SIN Ring Cyclotron

For the production of intensive meson beams, a ring cyclotron for a 100 μA proton beam at 590 MeV is presently being constructed at the Swiss Institute for Nuclear Research (SIN) near Villigen, in the northern part of Switzerland. The pre‐acceleration of the beam to 72 MeV will be accomplished by an AVF‐cyclotron, which can also be used for acceleration of d, He and heavy ions to variable energies. The status of the development and construction of the ring cyclotron is described.