Abstract: A time of flight (TOF) analysis device such as a TOF spectrometer is disclosed which includes a torch and sample introduction system for supplying a beam of ions to an orthogonal accelerator. The orthogonal accelerator deflects ions in the beam sideways to an ion reflector and then to a detector. The spectrometer includes a time to digital conversion circuit and an integrated transient recorder. The detector can include a series of dynodes and the voltage between dynodes can be varied in order to maintain a constant voltage between an ion sensitive surface and the last of the dynodes. A second ion mirror may be used for reflecting some of the ions towards the detector. The orthogonal accelerator is configured and powered to provide spatial focussing according to a predetermined condition. The spectrometer may also include vertical focussing for focussing the beam back to a size commensurate with the size of the detector after the beam has been focussed by beam forming optics.