Abstract: A method of operating an instrument which comprises a first and second ion stores, comprising determining whether a target accumulation time for the second ion store is greater than a threshold accumulation time. When the target accumulation time is less than the threshold accumulation time, ions are accumulated within the second ion store using an accumulation time that is based on the target accumulation time. When the target accumulation time is greater than the threshold accumulation time, ions are accumulated within the first ion store using a first accumulation time that is based on a difference between the target accumulation time and the threshold accumulation time, the ions accumulated in the first ion store are passed to the second ion store, and further ions are accumulated within the second ion store using a second accumulation time that is based on the threshold accumulation time.

Abstract: A mass spectrometer comprises: a first ion optical device in a relatively low gas pressure region; a second ion optical device in a relatively high gas pressure region, the first and second ion optical devices receiving respective RF voltages from respective RF power supplies for generating respective RF fields that confine ions in respective trapping regions of the ion optical devices; and a gas conductance restriction, restricting gas flow from the relatively high gas pressure region to the relatively low gas pressure region, the gas conductance restriction having an aperture to allow ions to pass from the second to the first ion optical device. The first and second RF power supplies are independent to allow the RF voltages for generating the first RF field to have a different amplitude from the RF voltages for generating the second RF field.

Abstract: The invention provides a data acquisition system and method for detecting ions in a mass spectrometer, comprising: a detection system for detecting ions comprising two or more detectors for outputting two or more detection signals in separate channels in response to ions arriving at the detection system; and a data processing system for receiving and processing the detection signals in separate channels of the data processing system and for merging the processed detection signals to construct a mass spectrum; wherein the processing in separate channels comprises removing noise from the detection signals by applying a threshold to the detection signals. The detection signals are preferably produced in response to the same ions, the signals being shifted in time relative to each other. The invention is suitable for a TOF mass spectrometer.

Abstract: A technique for time interval measurement is provided. First and second signal components are received, sampled and digitized. The first signal component is derived from a trigger signal that causes or indicates generation 5 of the second signal component. A time interval between the first and second signal components is determined based on a reference time defined by the sampled and digitized first signal component and based on a reference time defined by the sampled and digitized second signal component.

Abstract: A technique for time interval measurement is provided. First and second signal components are received, sampled and digitized. The first signal component is derived from a trigger signal that causes or indicates generation 5 of the second signal component. A time interval between the first and second signal components is determined based on a reference time defined by the sampled and digitized first signal component and based on a reference time defined by the sampled and digitized second signal component.

Abstract: The invention provides a data acquisition system and method for detecting ions in a mass spectrometer, comprising: a detection system for detecting ions comprising two or more detectors for outputting two or more detection signals in separate channels in response to ions arriving at the detection system; and a data processing system for receiving and processing the detection signals in separate channels of the data processing system and for merging the processed detection signals to construct a mass spectrum; wherein the processing in separate channels comprises removing noise from the detection signals by applying a threshold to the detection signals. The detection signals are preferably produced in response to the same ions, the signals being shifted in time relative to each other. The invention is suitable for a TOF mass spectrometer.