Particle selection method and a time-of flight mass spectrometer

Abstract

In the time-of-flight mass spectrometer, the mass spectrometer with high resolution is provided which defines the initial position and the initial velocity of the charged particles and selects only the stable charged particles to measure. First, all of the charged particles Pe are accelerated to one direction in a homogeneous or spatially uniform electric field during a common finite period of time, and then all of the charged particles Pe are accelerated to the opposite direction of the former in a homogeneous or spatially uniform electric field during a common finite period of time and given the same momentum in the opposite direction of the former. Two kind of particle selection method can be adopted. Only the charged particles Pe passing through a predetermined position at a predetermined time are selected by the selector. The charged particles Pe passing through the selector are defected by the first and second deflectors and then only the charged particles passing through a predetermined point of the slit are selected and reach the ion detector. Finally, the mass spectrum is obtained by measuring the time-of-flight of the particles using the ion detector.