| 摘要 |
An electrostatic ion trap for mass analysis includes a first array of electrodes and a second array of electrodes, spaced from the first array of electrode. The first and second arrays of electrodes may be planar arrays formed by parallel strip electrodes or by concentric, circular or part-circular electrically conductive rings. The electrodes of the arrays are supplied with substantially the same pattern of voltage whereby the distribution of electrical potential in the space between the arrays is such as to reflect ions isochronously in a flight direction causing them to undergo periodic, oscillatory motion in the space, focused substantially mid-way between the arrays. Amplifier circuitry is used to detect image current having frequency components related to the mass-to-charge ratio of ions undergoing the periodic, oscillatory motion. |
| 主权项 |
1. An electrostatic ion trap for mass analysis comprising:
a first array of electrodes and a second array of electrodes, spaced from the first array of electrodes, voltage being supplied, in use, to electrodes of the first and second arrays of electrodes to create an electrostatic field in the space between the electrode arrays, wherein electrodes of the first array and electrodes of the second array are supplied, in use, with substantially the same pattern of voltage, whereby the distribution of electrical potential in said space is such as to reflect ions isochronously in a flight direction causing them to undergo periodic, oscillatory motion in said space, focused substantially mid-way between said first and second arrays, wherein at least one electrode of said arrays is connected to amplifier circuitry for detection of image current having frequency components related to the mass-to-charge ratio of ions undergoing said periodic oscillatory motion in said space between the first and second arrays of electrodes, and wherein each said strip electrode extends in a drift direction of said periodic oscillatory motion and comprises a main segment and two end segments, and wherein a voltage difference between the main segment and the end segments creates a potential barrier for reflecting ions in the drift direction. |
