Ion optical system for MALDI-TOF mass spectrometer

A time-of-flight mass spectrometer comprising:

• a) a sample plate that supports a sample for analysis;
• b) a pulsed ion accelerator positioned proximate to the sample plate, the pulsed ion accelerator comprising an electrode electrically connected to the sample plate;
• c) an accelerator power supply having an output electrically connected to the pulsed ion accelerator, the accelerator power supply generating an accelerating potential that accelerates the pulse of ions produced from the sample positioned on the sample plate;
• d) an ion focusing electrode positioned after the pulsed ion accelerator, wherein a potential applied to the ion focusing electrode focuses the pulse of ions into a substantially parallel beam propagating in an ion flight path;
• e) a static ion accelerator positioned proximate to the ion focusing electrode and having an input that receives the pulse of ions focused by the ion focusing electrode, the static ion accelerator accelerating the focused pulse of ions;
• f) a field-free region positioned in the ion flight path after the static ion accelerator;
• and
• g) an ion detector having an input in the ion flight path of the focused and accelerated ions propagating in the field-free region, and having an output that is electrically connected to the sample plate, the ion detector converting the detected ions into a pulse of electrons.

A method of accelerating ions in a time-of-flight mass spectrometer, the method comprising:

• a) accelerating a pulse of ions generated from a sample by applying a voltage to an accelerator electrode;
• b) applying a static electric field proximate to the pulse of ions that accelerates the pulse of ions;
• and
• c) focusing the accelerated pulse of ions into a substantially parallel beam that propagates in an ion flight path.