Performance of a Penning Ion Source in the Oak Ridge Isochronous Cyclotron

Abstract

One year of operation of a heavy-ion Penning source in the Oak Ridge Isochronous Cyclotron has resulted in the acceleration of a number of isotopes of 17 elements, ranging from boron to tantalum. The method of positive identification of these beams and the operational techniques used to develop certain beams are described. Comparison of the extracted particle current for a given charge state with the calculated ionization potential has resulted in a systematic understanding of particle currents to be expected for undeveloped beams. In particular, shell effects and total ionization potential must both be considered in predicting beam intensities. The particle currents of ArR8+ Ar9+ and Ar10+ provide a sensitive test for the comparison of multiple and single impact calculations. The data are in agreement with multiple impact calculations. Also, low energy x-rays emitted from the Penning source have been detected and the observed spectra characterize the two modes of source operation.