METHOD AND APPARATUS FOR CORRECTION OF INITIAL ION VELOCITY IN A REFLECTRON TIME-OF-FLIGHT MASS SPECTROMETER

摘要

The present invention provides for a reflectron time-of-flight mass spectrometer in which there exists a curved field in a portion of the reflectron that takes into account acceleration and deceleration fields in upstream (from the ion source down to the reflectron) and downstream (from the reflectron down to the ion detector) regions, which are always present in any TOF-MS. The reflectron includes a decelerating section and a correcting section, with curved electric fields in the correcting and/or decelerating sections of the reflectron being considered. Moreover, analytic expressions are provided for calculating the profiles of the curved electric field in the second (correcting) section of the reflectron, which expressions are valid for arbitrary electric field distributions in the upstream and downstream regions as well as in the first (deceleration) section of the reflectron. These profiles will depend on the electric field distributions in the upstream and downstream regions and in the first (deceleration) section of the reflectron.