| 摘要 |
The invention relates to methods and devices for the detection of ions in an RF quadrupole ion trap. The invention consists of integrating a detector, such as a secondary-electron multiplier, into the end cap electrode with form and potential fit, thereby avoiding the ion outlet holes in the end caps, which might otherwise lead to field disturbances. Ions that leave the field by mass-selective and mass-sequential ejection using one of the known scan methods are measured when they impact on the end cap electrode. Both positive and negative ions can be measured. In the case of positive ions, it is also possible to measure the ions that impact on the side opposite the detector by means of their secondary electrons.
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