[en] Diagrams of the sputter target and plots of beam current as a function of the sputter target size and selected defining aperture are presented in an attempt to determine the smallest sputter target (cone) size usable to obtain reasonable negative ion beams

[en] The Argonne PIIECR ion source is the first ECR in source system to operate on a high voltage (350 kV) platform. The system is the injector into a new superconducting linac which will eventually provide beams over the entire periodic table, including uranium. The experience we have had with the system to date will be discussed. Emphasis will be placed on the source performance with solid materials and the initial performance of the system as an injector to the superconducting linac. The bunching system which is part of the overall source system allows a determination of the system longitudinal emittance. Results of these initial measurements will be presented. 4 refs., 2 figs., 1 tab

[en] The first beam from the Argonne PIIECR ion source was achieved on October 21, 1987. The major construction effort for both the source and high voltage platform is finished but a number of subsystems remain to be completed such as the remote control system and a gas handling system. Early source operation indicates that the major elements are functioning as designed, with the exception of the extraction high voltage insulation. Beam has been accelerated off the high voltage platform to a temporary atomic physics experimental area. The source is a major element in the ATLAS Positive Ion Injector project. 4 refs., 5 figs., 1 tab

[en] The ATLAS PII-ECR ion source is the first ECR ion source to be designed for operation in a high voltage platform. The source system is required to provide beams of heavy ions with a velocity of 0.01c for subsequent acceleration by the superconducting ATLAS Positive Ion Injector Linac. At present, the ability of the system to provide high charge state ions with velocities up to .01c is probably unique and as such has generated significant interest in the atomic physics community. A beamline for atomic physics has been installed and is now in use. The source began operation in October, 1987. The source capabilities and operating experiences to date will be discussed. 6 refs., 3 figs., 3 tabs

[en] Brief descriptions are given of the ion source test stand, the ANIS source, a copy of the SNICS source, and the Chapman inverted sputter source. Relative performance is discussed, particularly for the inverted sputter source. Beam currents are given for several ion species

[en] A surface ionization model with three body interaction is used to explain the mass spectra of negative ions from Cs sputter sources as well as their time dependence. The importance of the high diffusion rate from radiation damaged volumes is illustrated and the difficulties these may cause in quantitative mass spectroscopy with Cs sputter sources are discussed. The anomalously large emittance of single negative ions compared to clusters is ascribed to the surface formation and breakup of negative dimers. An example of negative molecule formation which does not proceed by a surface reaction is given. 16 refs., 2 figs., 1 tab

[en] The emittance of the inverted sputter source with immersion lenses was measured to be about 5π mm mrad MeV¹2/ at the 75% level over a wide range of beam intensities. The use of the source in experiments with radioactive sputter targets and hydrogen loaded targets is described. Self contamination of the source is discussed

[en] An experiment to improve the accuracy in the half-life value of ⁶⁰Fe by measuring both the amount of ⁶⁰Fe nuclei and the decay-rate of a spallation produced sample using the relation dN/dt = -lambda N is briefly discussed

[en] The feasibility of using a 30-watt pulsed NdYAG laser to ablate or evaporate material directly into the ECR had some initial exploratory runs and produced two distinctly interesting results. This technique holds the possibility of using small quantities of material, with a high efficiency, and being applicable to all solids. The laser illuminates a sample through one of the radial ports in the ECR main plasma chamber. The off-line tests indicated that our surplus (free) laser is capable of ablating significant quantities of interesting materials. The first tests of the laser ablation idea were carried out using a bismuth sample. The inherent pulsed nature of the technique allowed us to immediately study the time evolution of charge states in the ECR plasma. The results are directly comparable to model calculations and are completely consistent with the sequential stepwise stripping process which was assumed to dominate the high charge state production process. A paper describing our results will be presented at the 1995 International Ion Source Conference

[en] A summary of recent developments in ECRIS technology taking place at Argonne National Laboratory is presented in this paper. A pulsed laser for ablation of solid material into the source plasma has been used online with the ATLAS PII-ECRIS and has allowed direct time measurements to be made which verify and quantify sequential, step-by-step ionization taking place in an ECRIS. In addition, during the course of these laser studies a method was discovered which, from an operational viewpoint, represents an important new method for incorporating solid materials into an ECRIS. We also report on a new 14 GHz ECRIS currently under construction at Argonne. This new ECRIS, along with a new 300 kV high voltage platform and building addition, will further the capabilities of the ATLAS facility by providing the accelerator with a second, independent ECRIS