Keerthi's Papers

A collection of papers regarding ion source development.

Dual Frequency Enhancement of the SuperNanogan Multi-Charged Ion Source at TRIUMF ISAC Facility

In 2008, a Supernanogan ECR ion source from PANTECHNIK was introduced in addition to an in-house developed microwave ion source and a surface ion source to complement the TRIUMF Offline Ion Source (OLIS) facility to provide highly charged ions to ISAX experiments. Originally it employed a 400 W Travelling Wave Tube Amplifier (TWTA) for RF heating, but less than 50 W was enough to provide all the multi-charged ion beams required by the experiments. [cont]

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TRIUMF H-/D- Ion Source Development to Date

RIUMF’s 500 MeV cyclotron has been powered by an arc discharge H− ion source developed in-house 30 years ago. Since then, new additions to TRIUMF, like ISAC, have required increasing amounts of beam current from the cyclotron. The ARIEL facility will also require an additional 100 μA, in addition to the existing 300 μA required by the current beam lines. To meet the growing intensity demands of experiments, improvements in the source beam current and brightness are necessary. Due to historical reasons, the initial beam energy has been limited to 12 keV and the power to the source filament is limited to 2.5 kW. Therefore, the need for a state-of-the-art new ion source has become an increasingly prominent concern. This new source will be designed to produce a high-brightness 25 keV H− beam with a long filament lifetime. A historical overview of source development at TRIUMF will be presented, specifically regarding the new filament design, optimization multi-cusps, filter fields, and recent results from the ion source test bench.

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Off-line Ion Source Terminal

The off-line ion source (OLIS) terminal provides beams from stable isotopes to ISAC experiments as well as for accelerator commissioning and for pilot beams for radioactive beam experiments. The OLIS terminal is equipped with a microwave driven cusp source for single and double charge ions, a surface ion source for low energy spread alkali beams, and a multi-charge ion source.

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A multicharge ion source (Supernanogan) for the OLIS facility at ISAC/TRIUMF

The Off-Line Ion Source (OLIS) facility consists of a high voltage terminal containing a microwave cusp ion source, either a surface ion source or a hybrid surface-arc discharge ion source, and an electrostatic switch that allows the selection of any one of the sources without mechanical intervention. These sources provide a variety of +1 beams up to mass 30 for Isotope Separator and ACcelerator (ISAAC) experiments, commissioning the accelerators, setting up the radioactive experiments, and for tuning the beam lines. [cont]

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20 mA ion source with accel-accel-decel extraction

During the last three decades, TRIUMF has developed H- cusp ion sources for the 500 MeV, TR30, TR13 cyclotrons, as well as many other machines. These ion sources can be categorized as high current versions, producing up to 20 mA of DC H- beam within a normalized emittance (4RMS) of 0.6 π-mm-mrad and low current versions, producing up to 1 mA of CW current within a normalized emittance (4RMS) of 0.16 π-mm-mrad. A new state-of-the-art test stand is being built to further enhance H- knowledge while improving the brightness and filament life. The preliminary results of the test stand performances, as well as relevant emittance measurements, are discussed.

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60 mA DC H- multi-cusp ion source

This paper describes the latest high-current multi cusp type ion source developed at TRIUMF, which is capable of producing a negative hydrogen ion beam (H-) of 60 mA of direct current at 140V and 90A arc. The results achieved to date including emittance measurements and filament lifetime issues are presented. The low current version of this ion source is suitable for medical cyclotrons as well as accelerators and the high current version is intended for producing large neutral hydrogen beams for fusion research. The description of the source magnetic configuration, the electron filter profile and the differential pumping techniques given in the paper will allow the building of an arc discharge H- ion source with similar properties.

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