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.本文报道了一款印刷电路板（printed circuit board, PCB）的研制：该电路板可直接安装于质谱仪（mass spectrometer）的真空腔上，能够为离子导引杆、离子漏斗等多种非质量选择型离子操控器件提供所需的射频（radio frequency, RF）波形。本装置设计用于替代标准KF40法兰，可维持真空腔压力低于10^-6托（Torr），并集成了开源威斯康星振荡器射频电源的电路，可生成1~4 MHz、峰峰值电压（voltage peak-to-peak, Vp-p）最高达200 Vp-p的射频波形。在本次迭代的威斯康星振荡器设计中，我们新增了可变电阻以调控输出射频幅度，并验证了其离子传输性能与商用射频电源完全一致。通过该全新设计方案，我们大幅降低了驱动非质量选择型离子操控器件所需的空间与经济成本，我们预期该成果对开发低成本及/或便携式质谱系统的研究者颇具实用价值。