High-Speed Floating Potential Measurement with Phase-Flat Response up to 1 MHz for Sub-Ion Scale Turbulence in PANTA

Abstract

A high-speed floating potential measurement system has been developed for investigating turbulence at frequencies above the ion cyclotron frequency in the PANTA linear plasma device. The system is designed to have a phase-flat response up to 1 MHz, enabling accurate measurement of the phase relationship between floating potential and density fluctuations extending into the high-frequency regime. Initial results show that the attenuation of gain in the high-frequency range is significantly reduced compared to conventional measurements. A cross-phase analysis between the estimated electric field and density fluctuations shows a clear difference.