Abstract: A time-of-flight mass spectrometer comprising an accelerating portion that includes a repeller electrode and an extractor electrode, in which an inner surface on the extractor electrode side of the repeller electrode has a curved shape, the extractor electrode is a flat plate with a hole in the center or a plate structure including a mesh structure, and the accelerating portion converges a distribution of times of flight accompanying deviations in the acceleration start position of ions and also performs trajectory control by correcting a distribution of the introduction energy of ions. In accordance with the above-described structure, it is possible to realize both functions of a conventional accelerating portion and ion lens system with only an accelerating portion and it is possible to simplify and reduce the size of the 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.