Patent ID: 8563923

Claim:
An orthogonal acceleration TOF mass spectrometer having an orthogonal acceleration region into which ions are conveyed from a source in a first direction and then from which ions are accelerated in a second direction orthogonal to the first direction toward a detection means via a mass separation region comprising: said ion source for ionizing a sample to create a continuous beam of ions travelling in said first direction; a conductive box provided with an ion injection port and an ion exit port, said conductive box enclosing the orthogonal acceleration region and defining a lift region into which the created continuous beam of ions travelling in said first direction are introduced via the injection port; ion acceleration means placed inside or behind the conductive box and controlled to cause the ions to be accelerated in said second direction out of said conductive box and lift region via the exit port into said mass separation region in a pulsed manner in synchronism with a signal giving a starting point of measurement; and said ion detection means controlled to detect the ions in synchronism with the acceleration of the ions, and means for applying a lift voltage to the conductive box, controlled such that the lift voltage is applied at an instant of time after the continuous beam has entered the conductive box and prior to the acceleration of ions caused by said ion acceleration means.