US Patent 7772547 Multi-reflecting time-of-flight mass spectrometer with orthogonal acceleration

The disclosed apparatus includes a multi-reflecting time-of-flight mass spectrometer (MR-TOF MS) and an orthogonal accelerator. To improve the duty cycle of the ion injection at a low repetition rate dictated by a long flight in the MR-TOF MS, multiple measures may be taken. The incoming ion beam and the accelerator may be oriented substantially transverse to the ion path in the MR-TOF, while the initial velocity of the ion beam is compensated by tilting the accelerator and steering the beam for the same angle. To further improve the duty cycle of any multi-reflecting or multi-turn mass spectrometer, the beam may be time-compressed by modulating the axial ion velocity with an ion guide. The residence time of the ions in the accelerator may be improved by trapping the beam within an electrostatic trap. Apparatuses with a prolonged residence time in the accelerator provide improvements in both sensitivity and resolution.