Abstract: A ring magnet assembly has a generally cylindrical magnet body defining an air gap having an upper end and a lower end. Upper and lower face plates dispose respectively at an upper portion of the ring magnet and lower portion of the ring magnet. The face plates preferably have a high magnetic permeability. A mass analyzer may be disposed within the air gap. An ion generator may be disposed within an air gap of a ring magnetic assembly of the present invention. A pair of vertically-stacked magnetic ring assemblies may be provided. In that embodiment, a mass analyzer may be disposed within one air gap and an ion generator within another.

Abstract: A ring magnet assembly has a generally cylindrical magnet body defining an air gap having an upper end and a lower end. Upper and lower face plates dispose respectively at an upper portion of the ring magnet and lower portion of the ring magnet. The face plates preferably have a high magnetic permeability. A mass analyzer may be disposed within the air gap. An ion generator may be disposed within an air gap of a ring magnetic assembly of the present invention. A pair of vertically-stacked magnetic ring assemblies may be provided. In that embodiment, a mass analyzer may be disposed within one air gap and an ion generator within another.

Abstract: A method of separating ions according to mass in a mass spectrometer includes establishing a stream of ions traveling in a generally cycloidal path in an electric field and a magnetic field, subsequently causing the electric field to terminate for a predetermined period of time while maintaining the magnetic field thereby causing the electrons to travel in a generally circular path for a predetermined time period and subsequently reestablishing the electric field to cause further travel in a cycloidal path and providing a detector for receipt of some of the ions. A suitably programmed microprocessor is employed to control operation of the mass spectrometer and to receive electrical signals responsive to ions impacting on the detector to thereby provide information regarding the ions. Corresponding apparatus is provided.

Abstract: Ion detection apparatus has an ionizer provided with an ionizer volume for receiving a specimen to be analyzed. An electron gun is operatively associated with the ionizer for bombarding the specimen with an electron beam and converting the specimen into ions. An analyzer receives the ions from the ionizer volume and includes a detector for detecting the ions. The electron gun has focusing means for varying the size and intensity of the electron beam. The electron gun may have an accelerating anode, a focusing collimator and a second anode. The ionizer means may have an extractor lens and collimating lens as well as a groundplate. The ionizer means may have an electron collecting plate for receiving electrons which pass through the ionizer volume and providing feedback regarding the electron beam.

Abstract: An improved ion detector having a removable ionizer inlet assembly, a high vacuum chamber, an analyzer and a removable detector are provided. Valves are employed to permit replacement of the ionizer inlet assembly or the detector without meaningful loss of vacuum. The ionizer inlet assembly has a gap which is adjustable in order to permit more precise control of the molecules which are delivered to the ionizer. Adjustment is provided to control ions which are discharged from the ionizer assembly prior to delivery to the analyzer. Internal heating is provided for the ionizer inlet assembly zones. The ionizer preferably has generally longitudinally oriented slots to facilitate more efficient electron bombardment of the molecules.