摘要:
A Time of Flight mass analyser is disclosed comprising an ion detector comprising an Analogue to Digital Converter. Output signals from the ion detector are digitised and the arrival times and intensity values relating to ion arrival events are determined. If the determined arrival times from two signals fall within the same time window then the arrival times are added together in a weighted manner and the intensity values are combined.
摘要:
A collision or fragmentation cell is disclosed comprising a plurality of electrodes wherein a first RF voltage is applied to an upstream group of electrodes and a second different RF voltage is applied to a downstream group of electrodes. The radial confinement of parent ions entering the collision or fragmentation cell is optimized by the first RF voltage applied to the upstream group of electrodes and the radial confinement of daughter or fragment ions produced within the collision or fragmentation cell is optimized by the second different RF voltage applied to the downstream group of electrodes.
摘要:
A collision or fragmentation cell (4) is disclosed comprising a plurality of electrodes wherein a first RF voltage (7a) is applied to an upstream group of electrodes and a second different RF voltage (7b) is applied to a downstream group of electrodes. The radial confinement of parent ions entering the collision or fragmentation cell (4) is optimised by the first RF voltage applied to the upstream group of electrodes and the radial confinement of daughter or fragment ions produced within the collision or fragmentation cell (4) is optimised by the second different RF voltage applied to the downstream group of electrodes.
摘要:
A mass spectrometer is disclosed comprising a Time of Flight mass analyser comprising an ion detector comprising an Analogue to Digital Converter. Signals from the Analogue to Digital Converter are digitised and the arrival time and intensity of ions are determined. The arrival time T0 and intensity S0 of each ion arrival event is converted into two separate intensities S(n),S(n+i) which are stored in neighbouring time bins T(n), T(n+1).
摘要:
A Time of Flight mass analyser is disclosed comprising an ion detector comprising an Analogue to Digital Converter. Output signals from the ion detector are digitised and the arrival times and intensity values relating to ion arrival events are determined. If the determined arrival times from two signals fall within the same time window then the arrival times are added together in a weighted manner and the intensity values are combined.
摘要:
An ion guide or ion trap (1) is disclosed having an entrance electrode (2) and an exit electrode (3). The potential of the exit electrode (3) is periodically dropped for a relatively short period of time allowing some ions to escape from the ion guide or ion trap (1) via an aperture in the exit electrode (3). The period of time that the potential of the exit electrode (3) is dropped for is progressively increased and ions emerge from the ion guide or ion trap (1) in a mass to charge ratio dependent manner. The ion guide or ion trap (1) may be operated as a mass separator or low resolution mass analyser.
摘要:
A mass spectrometer is disclosed comprising a device (2) which is operable in a first mode of operation to separate ions temporally according to their ion mobility by applying a continuous axial electric field. The device (2) is also operable in a second mode of operation wherein ions are separated temporally according to the their mass to charge ratio by pulsing an applied axial electric field ON and OFF.
摘要:
An ion guide or ion trap is disclosed having an entrance electrode and an exit electrode. The potential of the exit electrode is periodically dropped for a relatively short period of time allowing some ions to escape from the ion guide or ion trap via an aperture in the exit electrode. The period of time that the potential of the exit electrode is dropped for is progressively increased and ions emerge from the ion guide or ion trap in a mass to charge ratio dependent manner. The ion guide or ion trap may be operated as a mass separator or low resolution mass analyser.
摘要:
A mass spectrometer is disclosed comprising an ion beam attenuator which attenuates an ion beam repeatedly switching between a zero transmission mode of operation during a time period ΔT1 and a non-zero transmission mode of operation during a time period ΔT2. The degree of attenuation of the ion beam can be varied by varying the mark space ratio ΔT2/ΔT1. The ion beam attenuator may release ions in packets or pulses but the packets or pulses of ions may be converted into a continuous ion beam by a relatively high pressure ion guide or gas collision cell arranged downstream of the ion beam attenuator.
摘要:
An ion guide or ion trap is disclosed having an entrance electrode and an exit electrode. The potential of the exit electrode is periodically dropped for a relatively short period of time allowing some ions to escape from the ion guide or ion trap via an aperture in the exit electrode. The period of time that the potential of the exit electrode is dropped for is progressively increased and ions emerge from the ion guide or ion trap in a mass to charge ratio dependent manner. The ion guide or ion trap may be operated as a mass separator or low resolution mass analyzer.