A 15 mA dc H Ϫ multicusp source has been developed for injection into a TR30 cyclotron. This source is also used with a 900 kV tandem accelerator to obtain 10 mA protons at 1.8 MeV. The program is an extension of the 5-7 mA dc H Ϫ cusp source developed at TRIUMF during [1989][1990]. Major efforts include the search for the optimal filament materials, shape, and location; comparison of cusp line confinement and magnetic filtering of electrons at the extraction region; optimization of extraction lense configuration; and upgrading of vacuum and power systems capability. The source is noncesiated and the maximum arc power available is only 5 kW. After the H Ϫ beams pass through an electron suppression grid and a 20 mm collimator, we obtained 15 mA with 0.66 mm mrad 4 rms normalized emittance. At this output the e/H ratio was about 4. The best normalized emittance occurs around 5-7 mA, having a value of 0.37 mm mrad. Further development in the near future is planned using cesium and multiple apertures in the hope of increasing dc H Ϫ currents to 30 mA while holding the normalized emittance below 0.75 mm mrad.

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The off-line ion source (OLIS) terminal consists of a microwave cusp ion source, either a surface ion source or a hybrid surface-arc discharge ion source and an electrostatic switch that allows selecting any one of the sources without mechanical intervention. These sources provide variety of beams to ISAC experiments, for commissioning the accelerators, for setting up the radioactive experiments, and for tuning the beam lines. The microwave ion source has been operational since 1995 and provides singly and doubly charged beams from various stable isotopes for many ISAC experiments at high and low energy areas. Originally its prime goal was to provide beams from gaseous elements, but later two ovens and a sputtering system were added in order to provide beams from liquids and from solids. The surface ion source installed in 2002 can provide low energy spread beams from alkali and semialkali elements. It also has three separate ovens and an ionizer. Therefore, it can provide three different temperature regions simultaneously to provide different beams to ISAC. It is mainly used for laser spectroscopy experiments and other experiments, which require a finite beam quality. A hybrid surface-arc discharge ion source was also developed and installed in order to meet specific demands from experiments. This source terminal is now automated for start up and for mass selection. It is capable of providing stable beams for months without maintenance and it is also capable of providing negative ion beams if required. To date, over 40 different isotopes including many rear isotopes were delivered to various experiments from the OLIS source terminal. Performances of the ion sources and some of the results are discussed.

The electron cyclotron resonance (ECR) charge state breeding method based on the PHOENIX source is first dedicated to the continuous high charge state radioactive ion production for cyclotrons, due to their q/m requirements, and to the high charge state production efficiency. It can be used as an injector for RFQ, linacs, and synchrotrons either in cw or pulsed operation. The efficiency of the 1+ to the n+ ion production and the charge breeding time are the fundamental parameters of the method, their dependence with regard to the 1+ ion beam emittance injected has been measured and will be discussed with regard to the radioactive ion beam acceleration. The efficiency of the process slightly decreases when injecting ion beam emittances higher than 30 π mm mrad, and remains constant in the 1+ radioactive intensity range available today and in the future. The ECR ion trap tuning associated with the afterglow mode permits the ionization, the accumulation, and the extraction of the injected primary beam keeping interesting efficiencies suitable to pulsed accelerators.

At TRIUMF, H− ion sources have been characterized on a teststand to improve the understanding of their performance. Measured beam characteristics such as current, emittance, and e∕H− ratio were correlated with source conditions as a function of relevant plasma parameters. Plasma densities, temperatures, and plasma potentials were measured with a Langmuir probe and correlated with beam properties for different confining magnetic fields and different values of arc power and gas pressure. The mechanism of beam extraction was studied by correlating plasma potential profiles with the corresponding plasma electrode bias voltages obtained from optimizing ion source outputs. Experiments with collar biasing and noble gas mixing were unsuccessful because of undesirable plasma potential profiles.