Vacuum steered-electron electric-field sensor


Williams, K. R., De Bruyker, D. P., Limb, S. J., Amendt, E. M., & Overland, D. A. (2013). Vacuum steered-electron electric-field sensor. Journal of microelectromechanical systems, 23(1), 157-167.


In a new type of microelectromechanical system (MEMS) electric-field sensor, a sheet of electrons is thermionically emitted by a hot cathode, flows through a vacuum, and is collected by a pair of anodes 2000 μm away. As the electrons move through the vacuum, they are steered by external electric fields, resulting in a differential current at the anodes. The micromachined tungsten cathode has a low-work-function coating and is suspended over a cavity on a glass chip. These sensors have been operated both in a vacuum chamber and sealed in glass vacuum tubes. Measured sensitivities in a vacuum tube at 10,100, and 1000 Hz are 470, 230, and 140 mV/m·Hz 1/2 , respectively; sensitivities in a vacuum chamber at the same frequencies are 34, 6.3, and 2.4 mV/m·Hz 1/2 , respectively.

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