Transverse emittance investigation of the ISOLDE target-ion sources

In order to produce target-ion sources allowing for a high isotopic resolution in the separator, CERN/ISOLDE (isotope separator on-line) has purchased a commercial emittance meter, capable of measuring transverse phase-space emittances, for ion-beam intensities down, to approximately I nA. It was installed at the ISOLDE off-line separator where targets are tested with respect to material purity and the ion-source efficiencies are determined. Now, also the emittance and brightness are measured for different stable elements. An extensive programme has been launched aiming at a complete survey of the emittance dependence on the various ion-source parameters. Results from the measurements on the different ISOLDE ion-source types, with associated analysis, are presented. (C) 2002 Elsevier Science B.V. All rights reserved.