Control of time front tilts in planar multi-reflection time-of-flight mass analyzers by local wedge fields

It is shown that an electrostatic field structure including a local wedge field in the area of small ion kinetic energies, followed by a planar accelerating field, allows to efficiently vary and control the inclination angle of time fronts (isochronous surfaces) in essentially parallel ion beams. When combined with deflectors, wedge fields allow independent control of the trajectory inclination angle and of the time front inclination angle. Two particular applications of local wedge fields are shown for improvement of planar multi-reflecting time-of-flight (MR-TOF) analyzers. One is a combination of an orthogonal accelerator and a deflector arranged for dense folding of ion trajectories. The other is a combination of an ion mirror and a deflector for reversing the ion motion and elongation of the flight paths.