Design of a Distributed Control System Based on Corba and Java for a New Rib Facility at Lnl

SPES (Study for the Production of Exotic Species) [1] is a L.N.L. project that will produce by the end of this year the design of a facility for Radioactive Ion Beams (RIBs) originated by fission fragments produced by secondary neutrons; it will be characterized by moderate size, performance and cost and will produce also intense neutron beams for activities both in fundamental and applied Nuclear Physics. In the context of this design study and tightly related to the medium size of this facility, the architecture of a distributed control system using the Common Object Request Broker Architecture (CORBA, [2]) as middleware framework and Java as main programming language was investigated for the core components (diagnostics, optics, RF-control) of the primary accelerator. The performances of CORBA middleware for the high level control system were measured in different conditions and shown to be sufficient to cover the requirements for remote operations (all feedback loops will be performed either in specialized hardware or by dedicated real-time embedded controllers). A minimal programming effort, a good level of modularity and long-term maintenance were some of the reasons to choose Java [3] and its related Integrated Development Environments (IDEs) as the main programming language and as a software platform for the Graphical User Interface (GUI) and the middleware implementations of this project. 1 SPES PRIMARY ACCELERATOR The primary accelerator of SPES is a LINAC for a high intensity proton beam (1-30 mA) up to an energy of 100 MeV. Fission fragments (RIBs) produced by the flux of neutrons will be then boosted by RFQs (Radio Frequency Quadrupole) structures and injected in an L.N.L. LINAC operating since 1995. The base components of this primary accelerator: a proton source (up to 80 mA) at 80 KV; a normal conductive RFQ at 5 MeV as low energy booster for a 30 mA proton beam; an ISCL (Independently phased Superconducting Cavity Linac) up to the final energy of 100MeV. The primary accelerator detailed design and construction will be performed in 2 steps: the first up to an energy of 10 MeV and the second upgrading the final energy from 10 to 100 MeV. By the end of this year a final approval for the first step is expected. 2 THE CONTROL SYSTEM OF THE PRIMARY ACCELERATOR