time-of-flight mass analyzer

Abstract

Provided is a time-of-flight mass spectrometer having an ideal reflectron which eliminates energy dependency of the flight time of ions having the same m / z while ensuring a high degree of design freedom. An electric field created by the reflectron is virtually divided into a decelerating region (B) for decelerating ions and a reflecting region (C) for reflecting ions. The decelerating region (B) is defined by one or more kinds of potential distributions arrange along a central axis, such as a one-stage uniform decelerating electric field or two-stage uniform decelerating electric fields. As for the reflecting region (C), its potential distribution is determined so that, for an ion having a certain mass-to-charge ratio which has departed from a predetermined point with initial energy higher than U d , the total flight time required for the ion to travel through a free-flight region (A) and the decelerating region (B) into the reflecting region (C), turn around in this reflecting region (C) and return to the original point will be equal to the total flight time required for an ion of the same mass-to-charge ratio to make a round trip in which the ion turns around at a point of the reference potential value at the boundary between the decelerating region (B) and the reflecting region (C) or in the decelerating region (B).

Description

technical field [0001] The present invention relates to a time-of-flight mass spectrometer, and more specifically, to a time-of-flight mass spectrometer using a reflectron. Background technique [0002] A time of flight mass spectrometer (hereinafter referred to as "TOFMS") utilizes that the flight speed of each ion when accelerating various ions depends on the mass-to-charge ratio, and measures the mass-to-charge ratio of each ion when these ions are caused to fly a fixed distance. The time of flight from which the mass-to-charge ratio of each ion is calculated. In TOFMS, the flight speed of ions depends on the initial energy given by the electric field, etc. Therefore, the flight time of each ion is energy-dependent, and the initial energy amplitude of ion clusters (groups of ions with the same mass-to-charge ratio) has a great influence on the device. Mass resolution has an impact. Therefore, in TOFMS, improving the energy convergence of the time-of-flight of ions is on...

AI Technical Summary

Problems solved by technology

However, such an approach has limitations, and improving time-of-flight energy convergence in a flight space containing reflectors is very important for improving mass resolution in TOFMS

Images