Development of a Portable Mass Spectrometer for Operation at 1 Tor

Portable mass spectrometers have obtained increased interests because they show great potential in different fields such as the industrial process analysis, forensics, environmental monitoring, space exploration and homeland security. Current major standard laboratory mass spectrometers have been miniaturized and their characteristics were investigated. The advantages and disadvantage of these different types of mass analyzers are also compared and examined.;Loeb-Eiber mass filter was proposed and reexamined as an alternate portable mass analyzer. Its unique paradigm makes it very suitable for development for portable mass spectrometers. The second generation Loeb-Eiber mass analyzer uses an array of short wires attached on the base instead of two long wires spooled on the base which greatly improves ion transmission to 25% from 6.25% of first generation analyzer. Also the capacitance reduced to 70 pF from 5000 pF of the first generation. The third generation Loeb-Eiber mass analyzer is fabricated based on silicon-on-insulator (SOI) using microelectromechanical system (MEMS). The electrode has square cross section that allows more ions oscillating in between adjacent electrodes compared to round electrodes. Different tuning circuits are also constructed to match the different mass filters. Glow discharge and electron ionization sources were also built and characterized.