Miniature Electrostatic, High-Vacuum Ion Pump Architecture Using A Nanostructured Field Emission Electron Source

[摘要] We report a field emission-based, electrostatic ion pump architecture for generation of high vacuum within a small chamber that is compatible with miniaturized cold-atom interferometry systems. The design increases the ionization probability using a helical electron collector. To create vacuum, electrons from a nanostructured field emitter array impact-ionize the gas molecules within the chamber; then, the ions generated are gettered by a negatively charged annular-shaped titanium ion collector. A proof-of-concept pump prototype was developed and characterized using a 200 cm3stainless steel vacuum chamber. The pressure inside the chamber was observed to decrease from 7.8×10-7Torr to 7.2×10-7Torr as the bias voltage on the ion collector was varied from -100 V to -1000 V while the emission current was kept constant at approximately 3.2 μA. The functional form of the experimental pump characteristics is in agreement with a proposed reduced-order model.

[发布机构] Microsystems Technology Laboratories, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge; MA; 02139, United States^1;ColdQuanta, Inc., 3030 Sterling Circle, Boulder; CO; 80301, United States^2

[效力级别] 能源学

[关键词] Cold atom interferometry;Electron collectors;Field emission electron sources;Field emitter arrays;Ionization probabilities;Negatively charged;Pump characteristics;Reduced order models