• F.W. Meyer, Y. Liu
  ORNL, Oak Ridge, Tennessee
• H.J. You
  Hanyang University, Seoul

In this paper, real-time, in-situ, plasma potential measurements are reported for an ECR ion source and correlated with extracted beam characteristics. The local real-time plasma potential of the ORNL CAPRICE ECR ion source was measured using an emissive probe, which was inserted perpendicularly from the plasma chamber wall at the mid-plane of the ECR zone between one of the six radial loss cones of the magnetic field structure, where perturbation of the main ECR plasma is expected to be small. Slots machined through the plasma- and puller-electrodes at the plasma chamber wall radius permitted insertion of the probe from the extraction side of the ECR source without perturbation of the coaxial microwave injection. The emissive probe technique permits plasma potential determination independent of plasma conditions and avoids problems related to probe geometry. The probe loop tip was pointed toward the chamber center in a radial plane and was located about 5 mm outside of the ECR zone. Details of the measurements, and a comparison with an external-beam-deceleration-based plasma potential determination will be presented.

• F.W. Meyer, M.E. Bannister, J.W. Hale, J.W. Johnson
  ORNL, Oak Ridge, Tennessee
• D. Hitz
  CEA Grenoble, Grenoble

We report on initial testing and implementation of a new high voltage platform recently installed at the ORNL MIRF. The platform is powered by a 250 kV, 30 kVA isolation transformer and features an all permanent magnet Electron Cyclotron Resonance (ECR) ion source, designed and fabricated at CEA/Grenoble, that utilizes microwave power levels of up to 750W in the frequency range 12.75 – 14.5 GHz to provide intense dc beams of singly and multiply charged ions for acceleration to energies up to 270 x q keV. The primary application of these ion beams is to study fundamental collisional interactions* of multicharged ions with electrons, atoms, and surfaces. More applied investigations in the area of ion implantation,** and ion beam development for use in semiconductor doping operations are carried out as well. Design details of the HV platform and the associated beamline-switchyard will be presented at the conference, together with performance characteristics of the all permanent magnet ECR source, of the beam transport from ion source to end-station, and of a novel electrostatic spherical sector beam switcher for directing beam to the various on-line experiments.

*F.W . Meyer, Trapping Highly Charged Ions: Fundamentals and Applications, J. Gillaspy, ed., Nova Science Pub., New York, 2000, pp. 117-164. **F. W. Meyer et al., AIP Conf. Proc. 635, p. 125 (2002).

• M.E. Bannister, F.W. Meyer, J. W. Sinclair
  ORNL, Oak Ridge, Tennessee

A control system for the 250-kV platform and beamlines for accelerating and transporting multiply-charged ion beams produced by an all-permanent-magnet ECR ion source has been developed at the ORNL Multicharged Ion Research Facility. The system employs Experimental Physics and Industrial Control System (EPICS) software controlling an Allen-Bradley ControlLogix Programmable Logic Controller (PLC). In addition to the I/O control points of the PLC, other devices are controlled directly by the EPICS computer through RS-232 and GPIB interfaces. PLC chassis are located at each major electrical potential of the facility, that is, at the ECR source potential, at the platform potential, and at ground potential used in the beamlines transporting ions to the various experimental end-stations. Connection of the control system components to the EPICS host is accomplished via EtherNet, including fiber optic links to the HV platform. The user interface is designed with the Extensible Display Manager (EDM) software and custom applets perform such tasks as mass-to-charge ratio scans of the platform analyzing magnet and archival of source and beamline operating parameters.