TIME-OF-FLIGHT MASS SPECTROMETER

摘要

Provided is a TOF MS equipped with an ideal reflectron that assures a high degree of freedom in design and in which the time of flight of ions having identical m/z does not depend on energy. The electric field formed by the reflectron is divided virtually into a deceleration region (B) where ions are decelerated and a reflection region (C) where ions are reflected, and the deceleration region is determined by one or more potential distributions, such as a first stage homogeneous decelerating electric field and a second stage homogeneous decelerating electric field, along the central axis. On the other hand, in terms of the reflection region, ions with a certain mass-to-charge ratio starting from a prescribed location under the parameters of the deceleration region are guided to the reflection region through a free-flight region (A) and the deceleration region. The potential distribution of those electric fields is determined by an analytical equation or numerical calculations such that time of flight for being turned around in the reflection region and returning to the original location is the same as the time of flight for ions with the identical mass-to-charge ratio having a return trajectory at the boundary between the deceleration region and reflective region or at a prescribed location within the deceleration region.