| 摘要 |
A system for supplying an RF voltage to an RF resonant load comprising an ion-optical component 6 of a mass spectrometer is disclosed. The system comprises a Direct Digital Synthesiser (DDS) arranged to output an RF voltage, the DDS preferably including a Numerically Controlled Oscillator (NCO) coupled to a modulator. The voltage supply system is arranged to determine a resonant frequency of the RF resonant load comprising the ion-optical component and, if it is determined that generation of an RF voltage at said frequency by the DDS would also result in the generation of an unwanted spur frequency close to said resonant frequency, to direct the DDS to generate an RF voltage at one or more preferred frequencies from a look-up table which are closest to said first resonant frequency. |
