Double-focusing mass spectrometer apparatus and methods regarding same

• Main Authors: DIAZ-DIAZ JORGE A, GENTRY W. RONALD, GIESE CLAYTON F
• Format: Patent
• Language: English
• Published: 31.12.2002
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

A double-focusing mass spectrometer apparatus includes a first cylindrical sector electrode defined at a first radial distance from a axis with the first cylindrical sector electrode having an upper and lower edge and a second cylindrical sector electrode surface defined at a second radial distance from the axis with the second cylindrical sector electrode having an upper and lower edge corresponding to the upper and lower edge of the first cylindrical sector electrode. An ion path is defined between the first and second cylindrical sector electrodes. A first magnet pole and a second magnet pole are positioned proximate the upper and lower edges of the first and second cylindrical sector electrodes, respectively, for providing a magnetic field in the ion path. A first and second array of electrodes, e.g., cylindrical segment electrodes, are positioned between the upper edges and lower edges of the first and second cylindrical sector electrodes, respectively, for use with the first and second cylindrical sector electrodes to provide a desired electric field in the ion path perpendicular to the magnetic field. In one configuration, the first and second cylindrical sector electrodes may not be required to provided the desired electric field but the electric field may be provided by the arrays of electrodes alone. Generally, the electrode arrays can be configured in a number of ways with application of appropriate voltages to attain the desired electric field, e.g., electrodes evenly spaced between the upper edges of the first and second cylindrical sector electrodes and electrodes evenly spaced between the lower edges of the first and second cylindrical sector electrodes with a predetermined voltage applied that varies logarithmically across the first and second arrays of electrodes. Methods for use in double focusing mass spectrometry are also provided, e.g., methods to provide the above apparatus.