Year: 2025
Type: article
Abstract: Quasi‐thermal noise (QTN) spectroscopy is a plasma diagnostic technique that enables precise measurements of moments for the local electron velocity distribution function. Previous studies on the QTN technique applied to weakly ionized collisional plasma were limited by the assumptions of unmagnetized and Maxwellian distributions. In this paper, we extend prior research by considering collisional and a secondary hot Maxwellian distribution. Further analysis indicates that as the collision frequency increases, the peak power spectral density at the decreases. In addition, we find that the influence of collisions on low‐frequency cyclotron harmonic signals in a magnetized plasma is mainly related to the plasma‐to‐electron cyclotron frequency ratio , but also has non‐trivial dependencies on the plasma Debye Length . Finally, we observed that in eight representative cases, the plasma harmonic disappearance frequency ratio is generally ∼0.25. Our research provides valuable theoretical guidance for the future application of QTN techniques in detecting plasma parameters, especially for collision frequencies typical of Earth's ionosphere.
DOI: 10.1029/2025ja034176
Institutions: University of Science and Technology of China, Observatoire de Paris, Laboratoire d’études spatiales et d’instrumentation en astrophysique, Deep Space Exploration Laboratory, University of Arizona, Royal Belgian Institute for Space Aeronomy, UCLouvain, Space Sciences Laboratory, University of California, Berkeley, Shenzhen University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7117354360