Progress with the superconducting cyclotron neutron therapy facility for Harper-Grace Hospitals

A compact superconducting cyclotron is being built for use as a neutron therapy device. The machine, which is being designed and assembled in the National Superconducting Cyclotron Laboratory at Michigan State University, is a 50 MeV deuteron cyclotron intended to produce neutrons by bombardment of an internal beryllium target with up to 20 μA of deuteron beam. In the course of the project certain aspects of the design have been modified, particularly relating to the dose delivery system (i.e. collimation, dose monitoring, light localisation) whilst other features (compensating filters, protective shutters) have been added to the design. Progress on the construction of the cyclotron is discussed and the proposed design of the dose delivery system is presented. (author)