APPLICATION OF A SQUARE-WAVE HF VOLTAGE IN A COMMERCIAL RF MASS-SPECTROMETER

We propose using a square-wave high-frequency (HF) signal with a varia ble frequency to expand the mass range of the IVA-1 radio frequency (R F) mass spectrometer which is designed for a sinewave HF voltage. Empl oying a square-wave voltage not only does not degrade the spectrometer 's resolution and sensitivity, in specific cases it may even improve t hem. Moreover, by using a square-wave voltage, the frequency can be ch anged without simultaneously matching the capacitive load of the RF ma ss-spectrometer analyzer. It has been shown experimentally that the re solution of the IVA-1 device with a square-wave voltage was identical to that in the standard operating mode, while the range of the detecte d mass is expanded to 1-160 amu for a square-wave frequency from 2.5 t o 10 MHz.