Patent ID: 8013292
Filing Date: 2011-09-06
Classification: H01J

Abstract:
1. A mass spectrometer having a multi-turn optical system for forming a closed loop orbit in which a plurality of sector-formed electric fields and free flight spaces free from an electric field are combined, and the mass spectrometer in which ions are made to fly along the loop orbit repeatedly so as to separate the ions in accordance with their mass-to-charge ratio, wherein: the multi-turn ion optical system is composed of a plurality of connected time-focusing unit structures, and each of the time-focusing unit structures comprises: a basic ion optical element for injection ion optical system is inserted in the injection-side free flight space in one of the plurality of time-focusing unit structures in such a manner that an ejection axis of the basic ion optical element for injection ion optical system coincides with an injection axis of the injection-side free flight space; and an injection-side free flight space is placed between an injection end of the basic ion optical element for injection ion optical system and an ion starting point which is an ion source, where the injection-side free flight space has a length uniquely determined by: a distance from an ejection end of the basic ion optical element for injection ion optical system to an injection end of a basic ion optical element in the time-focusing unit structure in which the basic ion optical element for injection ion optical system is inserted; a length of an injection-side free flight space, which is a distance between an ion injection point to the time-focusing unit structure and an ion injection point to the basic ion optical element of the unit structure; and a length of an ejection-side free flight space, which is a distance between an ion ejection point from the basic ion optical element of the time-focusing unit structure and an ion ejection point from the unit structure.