Multi-Needle Langmuir probe (mNLP) data on the Investigation of Cusp Irregularities (ICI) 4 sounding rocket

Documentation for file: ICI4_mNLP_01112021.mat The mNLP system on ICI-4 The mNLP system on ICI-4 consisted of four cylindrical Langmuir probes with a diameter of 0.51 mm and a length of 25 mm [1,2]. The instruments allowed for current measurements at a sampling rate of 8680.5 Hz. The mNLP data included in the file are 1) the raw currents (‘I_mnlp’) in which spikes have been removed using a median filter over ten data points, and 2) the “filtered currents” (‘I_mnlp_filt’). For the latter, the spin of the payload and the three first harmonics were removed using a band-pass filter [1,2]. Additionally, components with frequencies larger than 1kHz were also removed. Variables: Variable name Units Description/Comment time_noNans seconds Time of flight since launch. Alt Km Altitude of the payload. I_mnlp Ampere Currents obtained by the four cylindrical Langmuir probes. The 1st-4th columns contain the currents obtained by the probes with bias voltages of 3V, 4.5V, 6V, and 7.5 V, respectively. The data was filtered using a median filter over ten data points. I_mnlp_filt Ampere Same as I_mnlp with additional filtering of currents using band-pass filters [1,2]. Acknowledgement The mNLP experiment and the ICI-4 campaign were funded through the Research Council of Norway. Thanks to Lasse Clausen, Espen Trondsen, Jøran I. Moen, David Michael Bang-Hauge, Bjørn Lybekk, and the Mechanical Workshop at the University of Oslo, Norway. 1. Bekkeng, T. A., K. S. Jacobsen, J. K. Bekkeng, A. Pedersen, T. Lindem, J.‐P. Lebreton, and J. I. Moen (2010), Design of a multi‐needle Langmuir probe system, Meas. Sci. Technol., 21, 085,903, doi:10.1088/0957‐0233/21/8/085903 2. Jacobsen, K. S., Pedersen, A., Moen, J. I., & Bekkeng, T. A. (2010), A new Langmuir probe concept for rapid sampling of space plasma electron density. Measurement Science and Technology, 21(8), https://doi.org/10.1088/0957‐0233/21/8/085902This work was supported by the Research Council of Norway: Grant, 275653, 230996, 20800