Astronix proposes a particle beam generator for satellite thruster applications based on a novel MEMS technology for fabricating dense arrays of micron-scale particle guns in bonded silicon wafer substrates. Individual micro-guns as small as one micron crossectional diameter are possible, on a pitch of under 2 microns. A fully scalable array of the guns can deliver a laminar low-energy beam (<5keV) to a high voltage arrayed accelerator to achieve final energy of 100keV or more. Fabrication uses a new method of etching high-aspect ratio holes through laminated conductors. Greater than 107 guns per cm2 are possible. A current per ion gun in excess of a milliampere is possible, but 1 microamp/gun is suitable for thrusters of many newtons from a single 200mm wafer assembly. Ion guns interdigitated with electron guns create a charge neutral beam prior to high-voltage acceleration, making possible greater thrust than conventional thruster technology. The approach extends service life because of very low sputter erosion in the high-voltage electrodes, and requires no magnetic elements. The microgun approach was investigated under previous NRO and SBIR grants. Experiments to prove the manufacturing started recently with internal funding. A Phase 2 grant has been awarded to continue the work.
Benefit: In satellite applications, the approach offers higher thrust per unit area and small thruster size based on low-cost semiconductor manufacturing. The thruster architecture is fully scalable and thrust can be electronically regulated. With deflection circuitry, thrust can also be electronically vectored to eliminate mechanical gimbals and all other mechanical parts. The arrayed guns are redundant and highly fault tolerant, with low sputter erosion. No magnetics are required. Other applications include high performance electronics and semiconductor manufacturing equipment.
