The time of flight (TOF) describes the method used to measure the time that it takes for a particle, object or stream to reach a detector while traveling over a known distance. In time-of-flight mass spectrometry, ions are accelerated by an electrical field to the same kinetic energy with the velocity of the ion depending on the mass-to-charge ratio. Thus the time-of-flight can be used to determine the mass-to-charge ratio. The time-of-flight of electrons is used to measure their kinetic energy.… (More on Time-of-flight)