Electron density measurement of an ionospheric-like plasma using an impedance probe

In this work, an impedance probe was designed to measure ionospheric low-density plasma. The probe is made of short cylindrical dipoles with an antenna 20 cm in length and 0.25 cm in diameter, which can operate in the frequency range of 0–100 MHz. Combined with a vector network analyzer, the performance of the probe was tested in laboratory-created ionospheric-like plasma, and the results were compared with those of the Langmuir probe measurements. The densities measured by the two methods show a consistent trend, and the impedance probe data show much smaller uncertainties, which suggests that the impedance probe can achieve high-precision measurements. Furthermore, by fitting the antenna phase data, the electron-neutral collision frequency can also be obtained. Therefore, the impedance probe provides a feasible method for exploring low-density partially ionized plasma and can be expanded to actual ionospheric exploration in the future.