A Hybrid Vacuum Flange RF Oscillator for Low-Cost Mass Spectrometry

In this communication we report the construction of a printed circuit board which mounts directly to the vacuum chamber of a mass spectrometer and produces the RF waveforms needed by many nonmass-selective devices such as ion guides and ion funnels. Our device is designed to replace a standard KF40 flange, can maintain vacuum chamber pressures of less than 10–6 Torr, and contains the circuitry of the open-source Wisconsin Oscillator RF power supply to generate RF waveforms of 1–4 MHz and up to 200 Vp‑p. In this iteration of the Wisconsin Oscillator, we also introduce a variable resistor to control the output RF amplitude and show that its ion transmission capabilities are identical to those provided by commercial RF power supplies. With this new implementation we have greatly reduced the space and monetary requirements for driving nonmass-selective ion manipulation devices, which we expect to be advantageous to those developing low-cost and/or portable mass spectrometry systems.