Highly Efficient Sources of Negative Hydrogen Ions

The development of H- ion sources with performance exceeding those achieved today is a key requirement for the next generation of high power proton accelerators. Project X at Fermilab needs a CW H- Ion Source that satisfies demanding performance specifications: 10 mA CW beam current with normalized transverse rms emittance 0.2 mm mrad, fast chopping capability, fast intensity variation, and long (~ one month) lifetime. Currently, there is no H- source that satisfies these demands. In this project we propose to develop novel modifications of H- source designs which will satisfy these requirements. The new source will be an advanced version of a Penning DT SPS (Dudnikov-Type Penning Surface Plasma Source) with a high efficiency, deliver up to 15 mA average current with improved electrode cooling using new materials, fast chopping capability, and reduced cesium loss, have longer lifetime through suppression of electrode sputtering by back accelerated positive ions, and immunity to electrode shorting by flakes. The design of the advanced DT SPS with Penning discharge will be developed using computer simulations, including optimization of cooling, beam extraction, formation, chopping, and transport up to the RFQ. Suppression of electrode sputtering will be tested with ion source prototypes in the Fermilab Test Stand. Commercial Applications and Other Benefits: The two primary applications of the new source to be developed in this project are the next upgrade of the Fermilab Tevatron collider complex and the Project X Proton Driver. The source would also be an essential component of other proton drivers that might be used for muon colliders and for Accelerator Driven Subcritical (ADS) reactors. The source would be an upgrade path for many other existing and planned applications such as medical treatments (including hundred of cyclotrons with external injection for isotope production and cancer therapy, and high current tandem accelerators for Boron Neutron Capture Therapy), and homeland defense to produce resonant gamma ray techniques to detect explosives