Patent ID: 8461521

Claim:
A time-of-flight mass spectrometer comprising: a. an ion source that generates ions; b. a two-field ion accelerator having an input that receives the ions generated by the ion source, the two-field ion accelerator generating an electric field that accelerates the ions generated by the ion source through an ion flight path; c. a pulsed ion accelerator positioned in the ion flight path adjacent to the two-field ion accelerator, the pulsed ion accelerator generating an accelerating electric field that focuses the ions to a focal plane where the ion flight time to the focal plane for an ion of predetermined mass-to-charge ratio is independent to first order of an initial velocity of the ions prior to acceleration; and d. an ion detector positioned at the focal plane to detect ions, the two-field ion accelerator generating electric fields that cause the ion flight time to the ion detector for an ion of predetermined mass-to-charge ratio to be independent to first order of both the initial position and the initial velocity of the ions prior to acceleration.