Mass spectrometer having high sampling duty cycle

Abstract

A multi-reflecting time of flight mass spectrometer () comprising: a mass filter or mass separator (); an ion accelerator () for pulsing packets of ions; ion mirrors () arranged to receive the ions from the ion accelerator () and reflect them in a first dimension (x-dimension) between the ion mirrors () as the ions travel in a second dimension (z-dimension); first () and second () ion reflectors arranged such that when they are both activated they reflect the ions back and forth in the second dimension; an ion detector () arranged to receive the ions, when a first of the ion reflectors () is deactivated; and control circuitry configured to: control the ion accelerator () to perform a first pulse sequence that pulses a first plurality of packets of ions into the ion mirrors (); control the reflectors () such that ions in said plurality of packets are reflected back and forth in the second dimension by the reflectors () at the same time; and control the range of mass to charge ratios that is able to be transmitted by the mass filter or mass separator () to the ion accelerator (), and the timings at which the first reflector () is activated and deactivated, such that substantially all of the ions from said plurality of packets of ions undergo the same number of reflections in the second dimension before being received at the detector ().