Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. The RF field is usually collapsed prior to ion ejection. In an illustrative embodiment the RF power supply includes a RF signal supply; a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device; and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. Such ion storage devices are often used to store ions prior to ejection to a subsequent mass analyzer. The RF field is usually collapsed prior to ion ejection. The present invention provides a RF power supply comprising: a RF signal supply, a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device, and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. Such ion storage devices are often used to store ions prior to ejection to a subsequent mass analyser. The RF field is usually collapsed prior to ion ejection. The present invention provides a RF power supply comprising: a RF signal supply, a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device, and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.