B.A. Tatum

Control system for the Holifield Radioactive Ion Beam Facility

A new accelerator control system is being implemented as part of the development of the Holifield Radioactive Ion Beam Facility (HRIBF), a first generation radioactive ion beam (RIB) facility. The pre-existing accelerator control systems are based on 1970s technology and addition or alteration of controls is cumbersome and costly. A new, unified control system for the cyclotron and tandem accelerators, the RIB injector, ion sources, and accelerator beam lines is based on a commercial product from Vista Control Systems, Inc. Several other accelerator facilities, as well as numerous industrial sites, are now using this system. The control system is distributed over a number of computers which communicate over Ethernet and is easily extensible. Presently, implementation at the HRIBF is based on VAX/VMS, VAX/ELN, VME, and Allen-Bradley PLC5 programmable logic controller architectures. Expansion to include UNIX platforms and CAMAC hardware support is planned. Operator interface is via X-terminals. The system has proven to be quite powerful, yet it has been easy to implement with a small staff. A Vista users group has resulted in shared software to implement specific controls. This paper details present system features and future implementations at the HRIBF.

Development of the Holifield Radioactive Ion Beam Facility

The Holifield Radioactive Ion Beam Facility (HRIBF) construction project has been completed and the first radioactive ion beam has been successfully accelerated. The project, which began in 1992, has involved numerous facility modifications. The Oak Ridge Isochronous Cyclotron has been converted from an energy booster for heavy ion beams to a light ion accelerator with internal ion source. A target-ion source and mass analysis system have been commissioned as key components of the facilitys radioactive ion beam injector to the 25 MV tandem electrostatic accelerator. Beam transport lines have been completed, and new diagnostics for very low intensity beams have been developed. Work continues on a unified control system. Development of research quality radioactive beams for the nuclear structure and nuclear astrophysics communities continues. This paper details facility development to date.

Progress, status, and plans for the HRIBF project☆

Abstract Over the last three years, the Holifield accelerator system has been reconfigured into a first-generation radioactive ion beam facility, the HRIBF, a national user facility for RIB research. The construction and reconfiguration have been completed and the equipment commissioning and beam development phases have started. The progress to date, the present status, and future plans will be given. The special problems connected with the production and acceleration of RIBs will be discussed.

ORIC central region calculations

The central region for the K=100 Oak Ridge Isochronous Cyclotron, ORIC, will be modified to provide better orbit centering, focusing of orbits in the axial direction, and phase selection, in order to improve extraction efficiency, and reduce radioactive activation of cyclotron components. The central region is specifically designed for the acceleration of intense light ion beams such as 60 MeV protons and 15-100 MeV alphas. These beams will be used in the production of radioactive atoms in the Radioactive Ion Beam Project at Oak Ridge National Laboratory.

Design, construction, and field mapping of the HISTRAP prototype dipole

HISTRAP is a proposed 2.67 T-m synchrotron-cooler-storage ring having eight 45 degrees , C-design dipole magnets. A prototype dipole has been designed, fabricated, and mapped. The magnet design utilizes curved and angled coil ends to compensate for end effects in the field. Construction of the prototype dipole has been completed by the FNAL magnet factory. The magnetic field has been mapped using a Hall-effect probe affixed to a newly constructed, PC-based, horizontal positioning system. Results of the field mapping are presented. Results showing almost identical integrated and central profiles verified that the curved and angled coil end design did cancel the sextupole component found in typical C-shaped dipoles with straight coil ends. Except for the small quadrupole component, the predicted field profiles very accurately modeled the actual field profiles.<<ETX>>

Vacuum and beam diagnostic controls for ORIC beam lines

Vacuum and beam diagnostic equipment on beam lines from the Oak Ridge Isochronous Cyclotron is controlled by a dedicated system. The system is based on an industrial programmable logic controller with an IBM AT personal computer providing control room operator interface. Expansion of this system requires minimal reconfiguration and programming, thus facilitating the construction of additional beam lines. Details of the implementation, operation, and performance of the system are discussed.<<ETX>>

Radioactive beams with the HHIRF accelerators

It is pointed out that the two accelerators of the Holifield Heavy Ion Research Facility (HHIRF) provide a unique opportunity to quickly and economically develop an interim proton-rich, medium-intensity, ISOL-type, RIB (radioactive ion beam) facility. This extension of the HHIRF would provide for research and development until the much larger facility can be realized in the late 1990s. Presently, the Oak Ridge Isochronous Cyclotron (ORIC) serves as an energy booster for heavy ions from the 25-MW tandem accelerator. To produce RIBs, this process could simply be reversed. The tandem accelerator would be injected with heavy ions produced by ORIC. In this case, the two accelerators will be coupled by a thick target, ion source, mass separator, and charge exchange canal, all mounted on a 300-kV high-voltage platform in an existing shielded room. Light ions from ORIC, with an internal ion source, would produce radioactive heavy ions for tandem injection. Moreover, the UNISOR on-line isotope separator allows the timely development of the target-ion source hardware and chemistry. A central feature of this plan is that most of the main components already exist.<<ETX>>