Design of a multi-needle Langmuir probe system

作者：Bekkeng T A^*; Jacobsen K S; Bekkeng J K; Pedersen A; Lindem T; Lebreton J P; Moen J I

来源：Measurement Science and Technology, 2010, 21(8): 085903.

DOI：10.1088/0957-0233/21/8/085903

• Langmuir probe
• electron density
• ionosphere

The main goal of this work was to develop a Langmuir probe instrument for sounding rockets capable of performing high-speed absolute electron density measurements, and thereby be able to detect sub-meter ionospheric plasma density structures. The system comprises four cylindrical probes with a diameter of 0.51 mm and a length of 25 mm, each operated at a different fixed bias voltage in the electron saturation region. The probe diameter was chosen significantly less than the Debye shielding length to avoid complex sheath effects but large enough to ensure a probe area sufficiently large to accurately measure the electron currents drawn by the probes (in the range 1 nA to 1 mu A). The crucial feature of the University of Oslo's multi-needle Langmuir probe (m-NLP) is that it is possible to determine the electron density without the need to know the spacecraft potential and the electron temperature T-e. The m-NLP instrument covers a density range from n(e) = 10(9) m(-3) to 10(12) m(-3), with sampling rates up to 9 kHz. The m-NLP instrument was successfully tested on the ICI-2 (Investigation of Cusp Irregularities) sounding rocket flight from Svalbard on 5 December 2008.

• 出版日期2010-8