Mandrel for formation of mass spectrometer filter
AssigneeAnalog Technology Corporation
InventorsJames L. Lawrence, Jr., Robert A. Holzl, Frederick P. Pickett
Life of this patent
Estimating the term…
Abstract
A process for producing mass filters for use in mass spectrometers. Several electrodes having precisely shaped surfaces must be held in precisely determined positions with respect to each other. Insulators are placed into position on the surface of a mandrel and a layer of metal is deposited over the mandrel and insulators to form a composite unitary structure, including the electrodes. The deposited metal overlying the insulators is then removed, electrically isolating the electrodes.
Claims13
A male mandrel for use in forming a mass filter for use in a mass spectrometer, comprising:
- (a) a cylindrical portion extended along a common axis, having constant cross section, and having axially-extending electrode-defining surfaces which comprise the surfaces of a plurality of axially extending valley regions in said cylindrical portion, each valley region, including both its bottom and its sides, being outwardly concave and arcuate over the greater portion of its surface;
- terminated at its first end by an integral end surface perpendicular to the common axis;
- (b) a shank portion integral with said cylindrical portion having plane surfaces disposed perpendicular to the common axis for terminating said cylindrical portion at the end opposite its first end;
- (c) an end piece, having a plane surface large enough to cover the entire end surface of said cylindrical portion, for mounting on said cylindrical portion with its plane surface held tightly against the end surface of said cylindrical portion.
- (d) means for positioning the said end piece in contact with the first end of said cylindrical portion.
A mandrel for use in forming a chemically vapor deposited electrode of a mass filter thereon, comprising a longitudinally-extending body having a cylindrical axially-extending electrode-defining surface corresponding to the interior surface of a longitudinally-extending electrode of a mass filter, said axially extending electrode-defining surface comprising the surface of an axially extending valley region of said body, said valley region, including both its bottom and its sides, being outwardly concave and arcuate over the major portion of its surface.
An article for use in forming an electrode having an active inner surface for use in a mass filter, comprising:
- a. a mandrel having a cylindrical axially-extending electrode-defining surface corresponding to the interior surface of said electrode, said electrode-defining surface comprising an axially extending valley region of said mandrel, said valley region, including both its bottom and its sides, being outwardly concave and arcuate;
- and
- b. a coating of metal deposited on said mandrel by chemical vapor deposition.
Dependencies are inferred from the claim text.