Patent ID: 7456388

Claim:
A mass spectrometer comprising an ion guide and a mass analyzer, the ion guide defining a guide axis and adapted to provide an ion control field comprising a component for restraining movement of ions normal to the guide axis and comprising a component for controlling movement of the ions parallel the guide axis; the field having a controllable potential profile along the guide axis of the guide, the profile being adapted to provide for sequential release of the ions from the guide according to the mass-to-charge ratios of the ions and along a path parallel to the guide axis, wherein the same ion energy is applied to the ions over their travel through the ion guide to an extraction region disposed substantially along the guide axis irrespective of mass-to-charge ratio of the ions, and the ions are sequentially released with the same ion energy from the ion guide to provide for arrival of ions of substantially all released mass-to-charge ratios within the extraction region at substantially the same time.