Structural & Reinforcement Applications |
Technology Description
ESLI has investigated the design and fabrication of long-life ion thruster grids based on textured carbon. The combination of low sputter yield materials and densely-packed deep-surface microcavities form an erosion resistant surface for use in long-life ion grids.
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THREE POSSIBLE EROSION SITES: 1. TIPS - low erosion here if tips are sharp or charged 2. SHAFTS - low erosion here because of grazing incidence 3. BASE - low erosion here because redep is trapped in texture |
Potential Benefits
Long-life grids have dual use in spacecraft ion thrusters base-lined for New Millennium interplanetary missions as well as in commercial ion sources widely used in industry for materials processing. Spin-off applications are coatings materials for fusion reactors, laser dumps, black chambers, and cathode emitters.Development Status
ESLI performed a Phase 1 SBIR contract with NASA-JPL to develop long-life ion thruster grids for use in space propulsion and industrial applications. Phase 1 demonstrated that the texture survives sputter erosion because sputtered atoms remain trapped in the texture. Numerical simulation predicts that the achievable effective sputter yield should be less than 0.03 atoms/ion for conditions relevant to ion thruster missions. Initial processing of precision flat substrates was demonstrated on the 30-mm scale.Phase 2 work focused on the development of textured grids on the 150mm scale which were suited for 10,000 hr operation. Sputter resistance was characterized by ion etching and fabrication of full-scale grids was demonstrated.
NASA-JPL Phase 1&2 SBlR