Ion Accelerator System Research Articles

The ANL HVEM-tandem accelerator facilities

The ANL HVEM-TANDEM accelerator facilities are being developed to provide a unique combination of techniques for basic studies in the field of materials science. In addition to the methods of high voltage electron microscopy, the ion accelerator system will provide ion beam analysis and ion bombardment - implantation capability either in the HVEM or in an adjacent target area. The installation of the HVEM is completed and constitutes the first step in the development of a materials research laboratory, which will include a HVEM/ion beam interface with a 300 kV ion accelerator and a 2-MV tandem accelerator. The plan layout of these facilities is shown schematically in Figure 1.ANL's 1.2 MeV HVEM is an improved version of the AEI EM-7 and has a guaranteed resolution of 5 Å point-to-point. The design of the microscope contains a number of unique features. These include a specially designed ion beam access flight tube, instrumentation for two independently adjustable dark field conditions, 100 - 1200 kV continuous-mode accelerating voltage selection, a negative ion trap, and an ion- pumped specimen chamber.

A New Low Energy Heavy Ion Accelerator

A heavy ion accelerator and beam transport system have been designed and constructed for studies of the interaction of radiation with matter. The air-insulated electrostatic accelerator was made to our specifications by Radiation Dynamics, Inc., with a beam energy continuously variable from 2-200 Kev. A modified duoplasmatron ion source provides ions of hydrogen, nitrogen, oxygen and noble gases at beam currents as high as 5 ma. The accelerating potential is provided by an oil insulated power supply regulated to ± 0.01%. The beam transport system consists of a water-cooled insulated slit, magnetic spectrometer for beam definition of energy, charge state and isotopic composition, and a target chamber. A second magnetic spectrometer is available for further particle energy definition or for momentum analysis of the ion beam after interaction with a target. An extensive series of experiments for evaluating the accelerator performance are described, and results are reported for typical beam current density profiles, emittance areas, and maximum current densities attainable for different ions at various beam energies.