Mass spectrometers operate in a vacuum environment that requires a pumping mechanism to establish and maintain low pressure. In various pumping methodologies, a mass spectrometer may use an ion pump (see prior art FIG. 1) to achieve the internal vacuum associated with proper operation. The ion pump may achieve vacuum by ionizing molecules that drift into a cylindrical anode, then driving them to a cathode surface using an electric field. The ions thus sequestered in the cathode material may be removed from the vacuum space, and consequently, the pressure within the mass spectrometer may be reduced.
The ion pump is a limited-life item due to, for instance, degradation of a cathode surface occurring as a consequence of ion bombardment. An increased ion pump life is desired for many mass spectrometer applications, especially for applications involving remote sensing where the mass spectrometer is not easily accessed or serviced. Consequently, improvements to the manner in which the cathode surface is consumed should increase the lifetime and durability of the ion pump. This patent describes one or more manner in which the cathode lifetime may be extended.
USPTO Backgrounds
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