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The H- ion source employed in the Spallation Neutron Source* (SNS) is an RF-driven, multi-cusp source, which utilizes a helical antenna to inductively couple power into the source plasma. To date, the source has been successfully utilized in the commissioning of the SNS accelerator producing 10–40 mA of H- with duty-factors of ~0.1%. Ultimately, the SNS facility will require beam duty-factors of 6% and ~60 mA of H- injecting the linac. This may require currents of up to ~100 mA from the source depending on the ion source emittance. To date, the SNS source has only delivered sustained currents of ~33 mA at full duty factor. Therefore, we are developing plasma generators capable of achieving much higher plasma densities. Plasmas generated through helicon-wave coupling can develop densities up to 100 times greater than those produced by conventional inductive coupling. This report presents an initial design and discusses considerations for a source which combines the forward portion of the SNS source with a helicon system. The helicon system consists largely of components retrofitted from the proven hydrogen VASIMR system employed in space propulsion.
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