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US 4,786,806 AGranted
Retarding field spectrometer
AssigneeGAF Corporation
InventorsCarl A. Listl, Henry Seiwatz
Life of this patent
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AssigneeGAF Corporation
InventorsCarl A. Listl, Henry Seiwatz
Estimating the term…
A retarding field spectrometer has a mounting ring for attachment to the pole piece of a scanning electron microscope or similar beam generator. Supported by the mounting ring are three screen electrodes with their planes positioned normal to the beam axis and adjustable as a unit in a pseudo-orthogonal manner through two worm and gear drives of eccentrics cooperating with an aperture and a slot, respectively, in a plate carrying the electrode closest to the pole piece. Three continuous dynode electron multipliers are arrayed symmetrically about the beam at-rest axis between the last mentioned electrode and the intermediate electrode. The multipliers have cathodes maintained at substantially the same potential as the intermediate electrode. The electrode furthest from the pole piece is suspended from a mounting ring for the intermediate electrode by means of criss-crossing strands of a continuous plastic monofilament permitting orthogonal adjustment of the furthest electrode relative to the intermediate electrode while insulating electrically one from the other.
A retarding field spectrometer in combination with a modulatable and deflectable electron beam generator which generator has a pole piece with an orifice from which said beam emanates, said spectrometer comprising in combination an array of three electron transmissable electrodes joined for mounting in the path of said beam between said pole piece and a target holder, means for individually energizing each of said electrodes with a discrete biasing voltage, means for applying a reference potential to a target in said target holder, and at least one continuous dynode electron multiplier detector of secondary electron emission comprising a cathode entryway positioned between those two of said electrodes that are situated nearest to said pole piece.
Dependencies are inferred from the claim text.