| 摘要 |
A double-focusing mass spectrometer apparatus includes a first cylindrical sector electrode defined at a first radial distance from an axis with the first cylindrical sector electrode having an upper and lower edge and a seco nd cylindrical sector electrode surface defined at a second radial distance fro m the axis with the second cylindrical sector electrode having an upper and lower edge corresponding to the upper and lower edge of the first cylindrica l 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 o f the first and second cylindrical sector electrodes, respectively, for use wi th 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 provide the desired electric field but the electric field may be provided by the arraysof electrodes alone. Generally, the electrode arrays can be configured in a number of ways with application of appropriate voltag es to obtain 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 vari es longarithmically across the first and second arrays of electrodes. Methods f or use in double-focusing mass spectrometry are also provided, e.g., methods to provide the above apparatus.
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