| 摘要 |
A time of flight (TOF) mass analyzer is disclosed comprising an annular ion guide having a longitudinal axis and comprising a first annular ion guide section and a second annular ion guide section. Ions are introduced into the first annular ion guide section so that the ions form stable circular orbits therein about the longitudinal axis. The ions are then orthogonally accelerated in a first axial direction into the second annular ion guide section in such a manner that time of flight dispersion of the ions occurs only in the longitudinal direction and ions are spatially focused to an isochronous plane which is substantially perpendicular to said longitudinal axis. An axial DC potential is also maintained along at least a portion of the second annular ion guide section so that the ions are reflected back through the ion guide, the ions undergoing multiple axial passes through the second annular ion guide section before being detected by an ion detector located at said isochronous plane. |
