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.