Implementation of radio-frequency compensation for enhanced Langmuir single probes on linear plasma device Linear Experiment Advantage Device

Radio-frequency (RF) oscillations may distort the current–voltage (I–V) characteristics obtained from Langmuir single probes, potentially compromising the accuracy of plasma density ( n_\mathrme ) and electron temperature ( T_\mathrme ) measurements. To address these measurement challenges, an enhanced Langmuir probe system with 13.56 MHz RF compensation has been implemented on the linear plasma device Linear Experiment Advantage Device (LEAD). The compensation mechanism employs an auxiliary electrode with optimized geometry and impedance characteristics to stabilize and correct the probe potential. Notably, a four-stage notch filter network has been integrated between the probe tip and the scanning power supply, demonstrating effective suppression of both fundamental (13.56 MHz) and second-harmonic(27.12 MHz) oscillations. Validation experiments comparing the performance with that in conventional probe configurations revealed that the compensated probe achieves significantly reduced I–V curve distortion, translating to enhanced measurement reliability. The implemented compensation methodology provides valuable insights for optimizing Langmuir probe configurations and enhancing diagnostic reliability in RF-dominated plasma environments.