| Patent application number | Description | Published |
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| 20100019144 | AUTOMATIC GAIN CONTROL (AGC) METHOD FOR AN ION TRAP AND A TEMPORALLY NON-UNIFORM ION BEAM - An automatic gain control (AGC) technique and apparatus is introduced herein for any temporally non-uniform ion beam, such as, for example, an ion beam produced by a MALDI ion source so as to minimize space charge effects. The disclosed configurations and techniques can be achieved by using an ion optical gating element and applying a desired signal waveform (e.g., a square wave) having a predetermined duty cycle. The applied voltage amplitude of such a signal can be configured to switch between a voltage which fully transmits the ions, and a voltage which does not transmit any ions. The frequency is chosen to result in a period which is significantly lower than the smallest non-uniformity period. Techniques of the present invention can also be extended to methods of AGC which can use a single ion injection event from the ion source to avoid variations in ion numbers from an unstable ion source. | 01-28-2010 |
| 20100059666 | Methods of Calibrating and Operating an Ion Trap Mass Analyzer to Optimize Mass Spectral Peak Characteristics - A method for calibrating an ion trap mass spectrometer is disclosed. The method includes steps of identifying a phase (defined by the RF trapping and resonant ejection voltages) that optimizes peak characteristics, and then determining, for each of a plurality of calibrant ions, an optimal resonant ejection voltage amplitude when the ion trap is operated at the identified phase. The resonant ejection voltage applied to the electrodes of the ion trap may then be controlled during analytical scans in accordance with the established relationship between m/z and resonant ejection voltage amplitude. | 03-11-2010 |
| 20100059670 | Two-Dimensional Radial-Ejection Ion Trap Operable as a Quadrupole Mass Filter - A two-dimensional radial-ejection ion trap is constructed from four apertured electrodes having inwardly facing hyberbolic surfaces, with each electrode being spaced from the centerline by a distance r that is greater than the hyperbolic radius r | 03-11-2010 |
| 20100282957 | Ion Population Control in a Mass Spectrometer Having Mass-Selective Transfer Optics - Methods for operating a mass spectrometer having at least one component having mass-dependent transmission, comprising: injecting a first sample of ions having a first mass range into an ion accumulator for a first injection time under first operating conditions suitable for optimizing transmission of ions of the first range; acquiring a full-scan mass spectrum of the first sample of ions; selecting ion species having a second mass range different than the first range; calculating a second injection time, the second injection time suitable for injecting a population of the selected ion species into the ion accumulator under second operating conditions suitable for optimizing transmission of ions of the second range; injecting a second sample of ions having the selected ion species into the ion accumulator for the second injection time under the second operating conditions; and acquiring a mass spectrum of ions derived from the selected ion species. | 11-11-2010 |
| 20100282963 | Prolonged Ion Resonance Collision Induced Dissociation in a Quadrupole Ion Trap - A technique is disclosed for conducting collision induced dissociation (CID) in a quadrupole ion trap (QIT) having higher order field components. In order to compensate for the shift in the frequency of motion with amplitude of the excited ions arising from the influence of higher-order field components, the amplitude of the RF voltages applied to the QIT is monotonically varied during the excitation period to prolong the condition of resonance, resulting in higher average kinetic energies of the excited ions. Thus, higher fragmentation efficiencies may be obtained, or a targeted level of fragmentation may be achieved in less time relative to conventional CID. | 11-11-2010 |
| 20110012013 | Methods of Calibrating and Operating an Ion Trap Mass Analyzer to Optimize Mass Spectral Peak Characteristics - A method for calibrating an ion trap mass spectrometer is disclosed. The method includes establishing an optimal phase and amplitude-m/z relationship by acquiring peak quality data at varying values of amplitude and phase. The resonant ejection voltage applied to the electrodes of the ion trap may then be controlled during analytical scans in accordance with the established relationship between m/z and resonant ejection voltage amplitude. | 01-20-2011 |
