Abstract: An electrical feedthrough connector to a low pressure (vacuum) chamber such as in a mass spectrometer comprises an epoxy body having at least two generally cylindrical portions with a step between the two generally cylindrical portions and with the portions mating with circular openings in the housing for the low pressure chamber. A step between the two cylindrical portions of the electrically insulating body mates with a step in the opening in the chamber housing with a gasket such as an o-ring placed between the steps to provide a pressure seal. A rigid printed circuit board with electrical components for an interconnect circuit is affixed to one end of the electrically insulating body with a flexible printed circuit connector extending from the rigid printed circuit board through the epoxy body to the low pressure chamber for interconnecting components within the chamber.

Abstract: A generally circular mass spectrometer and ion filters used therein have hyperbolic pole pieces which can be machined by diamond turning. In a quadrature assembly, two pole segments can be identical and provide the outer arcuate pole surfaces, and two segments can be identical and provide the inner arcuate pole surfaces opposite from the outer pole surfaces. A support plate has an arcuate outer surface which engages alignment surfaces of the pole segments, the alignment surfaces and outer support surfaces being machined by turning. In a quadrapole, one outer pole piece and one inner pole piece are mounted on each support surface of the plate with the alignment surfaces in abutment with the support plate outer surface for accurate alignment. An outer pole segment on one support surface is electrically connected to an inner pole segment on the opposing support surface. Each support segment has a plurality of spokes for mounting to the support plate.