Patent ID: 6903332

Claim:
A pulser apparatus for a time-of-flight mass spectrometer that provides acceleration of a beam of ions in a pulser region, the acceleration being in a direction perpendicular to an initial ion beam direction, wherein ions of the ion beam are introduced to the pulser region during a filling stage and accelerated out of the pulser region during an ejection stage, the apparatus comprising: a pusher diaphragm located to a side of the pulser region away from a main field region toward which the ions are to be accelerated, the pusher diaphragm having a voltage potential that is switched from a first pusher voltage level to a second pusher voltage level when starting the ejection stage; a puller diaphragm located to a side of the pulser region opposite the pusher diaphragm, the puller diaphragm having a voltage potential that is switched from a first puller voltage level to a second puller voltage level when starting the ejection stage; and a compensation diaphragm located between the puller diaphragm and the main field region, the compensation diaphragm having a voltage potential that is switched from a first compensation voltage level to a second compensation voltage level when starting the ejection stage so as to minimize penetration of a field from the main field region to the pulser region.