The influence of probe spacing and probe bias in a double Langmuir probe setup

Multi-needle Langmuir probes are mounted on satellites and sounding rockets for high-frequency characterization of plasma in the ionosphere. Mounted a spacecraft, recorded probe current often differs from expected results. In this paper, we perform numerical study using particle cell model to see how spacing between individual used multi-needle setup influences measured current. We also applied bias voltage can contribute deviations. our study, use realistic electron temperatures densities relevant part However, results should be generally applicable valid other space environments as well laboratory applications. From that when distance is short, less than two Debye lengths, highly affected, deviations more 60% compared single setup.