Ion mobility spectrometer with virtual aperture grid

DWPI Title: Ion mobility spectrometer connects adjacent electrodes to source free charge such that virtual aperture grid is provided at end of drift region
Abstract: An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.
Use: Ion mobility spectrometer.
Advantage: Since each of the adjacent electrodes is connected to a source of free charge, a virtual aperture grid is provided at the end of the drift region hence the ion collector is shielded from the mirror current of the ion swarm hence the need of a physical aperture grid is eliminated.
Novelty: The spectrometer has a drift tube (31) comprising a drift region (15) in which the ions drift against a counter-flowing drift gas (16) under the influence of an electric field (34) established by multiple stacked electrodes (32). The stacked electrodes adjacent to an ion collector (27) have an electrode pitch that is less than the width of an ion swarm. Each of the adjacent electrodes is connected to a source of free charge such that a virtual aperture grid is provided at the end of the drift region that shields the ion collector from the mirror current of the ion swarm.
Filed: 12/16/2008
Application Number: US2008336270A
Tech ID: SD 10700.0
This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention.
Data from Derwent World Patents Index, provided by Clarivate
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