time-of-flight mass analyser

time-of-flight mass analyser

A mass analyser used in mass spectrometry that measures ion mass by determining the flight time of ions having the same kinetic energy over a fixed distance. Ions are formed in the same place at the same time, and given the same energy by an acceleration voltage as they pass into a flight tube.

The TOF/MS acts as a “racetrack” for ions: lower mass ions move at higher speed; higher mass ions move at lower speed. Determination of the time of arrival of ions after the start signal serves to differentiate ion masses.