Quadrupole gas analyzer comprising four flat plate electrodes

Claim 2

A quadrupole mass analyzing device for analyzing charged particles by charge to mass ratio comprising four flat plate electrodes disposed within the device where a first nonadjacent pair of said electrodes is separated by a first distance and a second nonadjacent pair of said electrodes is separated by a second distance, and means for applying superimposed DC and sine wave AC voltages to said electrodes, the voltages applied to said first pair of electrodes being equal and the voltages applied to said second pair of electrodes being equal and being opposite in polarity to the voltages applied to the first pair of electrodes.

Claim 3

A quadrupole device as in claim 1 where said first distance equals said second distance.

Claim 4

A quadrupole device as in claim 2 where said first pair of electrodes are parallel to one another and said second pair of electrodes are parallel to one another.

Claim 5

A quadrupole device as in claim 1 where said first pair of electrodes are parallel to one another.

Claim 6

A quadrupole device as in claim 4 where said second pair of electrodes are parallel to one another.

Claim 7

A quadrupole device as in claim 4 where said second pair of electrodes are coplanar.

Claim 8

A quadrupole device as in claim 6 where each of said second pair of electrodes is (1) narrower in width than each of said first pair of electrodes and (2) disposed between said first pair of electrodes.

Claim 9

A quadrupole mass analyzing device for analyzing charged particles by charge to mass ratio comprising four flat plate electrodes symmetrically disposed within the device where a first nonadjacent pair of said electrodes has applied thereto a first voltage (U+V cos wt) and a second nonadjacent pair of said electrodes has applied a second voltage -(U+V cos wt) thereto where U a DC voltage; V the half-amplitude of an AC voltage; w the angular frequency of the AC voltage; and t time.

Claim 10

A quadrupole mass analyzing device for analyzing charged particles by charge to mass ratio comprising four flat plate electrodes symmetrically disposed within the device where a first nonadjacent pair of said electrodes has applied thereto a first voltage (U+V cos wt) and a second nonadjacent pair of said electrodes has applied a second voltage -(U+V cos wt) thereto where U a DC voltage; V the half-amplitude of an AC voltage; w the angular frequency of the AC voltage; and t time.

Claim 11

A quadrupole device as in claim 8 where each said flat plate is disposed in proximity to the two plates adjacent to it so that the array of said plates is square in cross section.

Claim 12

A quadrupole device as in claim 8 where said plates are disposed parallel with respect to one another.

Claim 13

A quadrupole device as in claim 8 where each of said flat plates comprises a thin, metallic ribbon disposed on a support.

Claim 14

A quadrupole device as in claim 8 where said device includes at least one source of potential in addition to the DC and AC voltages applied to said four electrodes, the dimensions of each electrode being such that the coefficient C1 in the expression phi (r, theta ) Co(r/ro)2cos2 theta +C1 (r/ro)6 cos 6 theta +-Cn (r/ro)2(2n 1)cos2(2n+1) theta where phi (r, theta ) the potential duE to the applied fields at radius r and angle theta with respect to the axis of symmetry of said electrodes, ro the distance from the axis of symmetry to said electrodes, and C1, C2-Cn are constants defined by the potentials applied and the dimensions of the structure, is no more than 10 percent of the value of Co.

Claim 15

A quadrupole device as in claim 12 where the potential is the potential on a cylindrical tube which surrounds said four electrodes and where each said flat plate is disposed in proximity to the two plates adjacent to it so that the array of said plates is square in cross section.

Claim 16

A quadrupole device as in claim 13 where said cylindrical tube is grounded.

Claim 17

A quadrupole device as in claim 14 where said plates are symmetrically disposed within said tube, the radius of said tube being R and where the width, 2l, of each plate is approximately specified as follows: where ro the distance from the center of said array of plates to the surface to said plates.