A Micro-machined Energy Mass Spectrograph for Microsatellite Applications

RSI, an Industrial Associate of the Princeton University Photonics and Optoelectronic Materials group, proposes the development of a micro-chip energy-mass spectrograph for space environment sensing aboard microsatellites. The micro-machined energy-massspectrograph (M2-EMS) is envisioned as a micro-miniaturized replacement for conventional particle energy and mass detection systems employed as space environment sensors. The M2-EMS would employ parallel electric and magnetic fields to separate particlesby their energy:charge and mass:charge ratios. The spectrograph apertures would be micro-machined from Si wafers by anisotropic etching. Charged particle optic electrodes would be grown on the surface by thick photoresist lithographic electroformingtechniques. By using electroless deposition of Ni (a ferromagnet) into thick resist molds, magnetic field provided by external NdFeB permanent magnets can be channeled to provide high field regions for mass separation. By applying opposite potentialpolarities to the straight-wall Ni features, a region of high electric field can be produced to simultaneously separate particles by energy. Detection of spatially separated ions could be achieved by existing multichannel area detectors. Using multipleapertures with varying magnetic and electric separation fields atop the same multichannel detector, parallel detection of different energy and mass ranges can be achieved.