Sökning: "Langmuir probes"

Visar resultat 1 - 5 av 9 uppsatser innehållade orden Langmuir probes.

1. 1. Calibration of RPWI Langmuir Probe Data

   Kandidat-uppsats, Uppsala universitet/Institutet för rymdfysik, Uppsalaavdelningen

   Författare :Gurpreet Kaur; [2023]
   Nyckelord :RPWI;

   Sammanfattning : In this report calibration of the four probes attached onto the JUICE spacecraft has been made.The JUICE spacecraft (JUpiter Icy Moon Explorer) is a spacecraft which will investigate theenvironment on and around Jupiter and its four biggest moons. LÄS MER

3. 2. Spatial Variability in the Ionosphere and GNSS Signal Delays in the L-band: A Direct Comparison of In-Situ Satellite- and Swepos-Data

   Kandidat-uppsats, Uppsala universitet/Institutionen för fysik och astronomi; Uppsala universitet/Institutet för rymdfysik, Uppsalaavdelningen

   Författare :Oscar Suneson; [2021]
   Nyckelord :fysik; jonosfären; GNSS; GPS; astrofysik; navigationssystem; mätteknik;

   Sammanfattning : It has been shown that ionospheric irregularities can disturb our GNSS (Global Navigation Satellite System) communication. This disturbance is caused by scintillation of the radio signals when they pass through the ionosphere, leading to lock-on difficulties or in worst case, a loss of position for the GNSS-receiver. LÄS MER

4. 3. Low–voltage External Discharge Plasma Thruster and Hollow Cathodes Plasma Plume Diagnostics Utilising Electrostatic Probes and Retarding Potential Analyser

   Master-uppsats, Luleå tekniska universitet/Rymdteknik

   Författare :George-Cristian Potrivitu; [2016]
   Nyckelord :space electric propulsion; in-space advanced propulsion technology; Hall effect thruster; hollow cathode; wall-less Hall thruster; external discharge plasma thruster; single Langmuir probe; double Langmuir probe; emissive probe; retarding potential analyzer; plume plasma diagnostics; low-voltage Hall thruster; high-current hollow cathode; plasma parameters; propulsion electrique pour l espace; cathode creuse à fort courant; propulseur à décharge externe de plasma; propulseur à effet Hall à basse tension; techniques de diagnostic du plasma; sonde de Langmuir simple; sonde de Langmuir double; sonde émissive; analyseur à potentiel retardé;

   Sammanfattning : The present thesis is the result of a research period at the Institute of Space and Astronautical Science of the Japanese Aerospace Exploration Agency, ISAS/JAXA within Funaki Laboratory of the Department of Space Flight Systems that followed the path of plume plasma diagnostics for space electric propulsion drives. During the experimental studies two high-current hollow cathodes and an innovative prototype of a low-voltage fully external discharge plasma thruster (XPT) had their plasma plumes diagnosed using electrostatic probes and retarding potential analyser (RPA). LÄS MER

5. 4. Rosetta Langmuir probe performance

   Master-uppsats, Institutionen för fysik och astronomi

   Författare :Fredrik Johansson; [2013]
   Nyckelord :Rosetta; SPIS; SPIS 5; Langmuir; Probe; Plasma; Probe sweep; Potential; Simulation; PIC; IRF; Swedish Institute of Space Physics; ESA;

   Sammanfattning : Several Langmuir probe voltage sweeps by a model of the ESA spacecraft Rosetta was simulated in a plasma with solar wind parameters using the ESA open source software SPIS 5. The simulations were carried out to in- vestigate the features of the spacecraft’s environment in the solar wind and the effect of photoemission from the spacecraft surface on the measurements made by the Langmuir probes on board Rosetta. LÄS MER

7. 5. Noise sources in the electric field antenna on the ESA JUICE satellite

   Uppsats för yrkesexamina på avancerad nivå,

   Författare :Elias Odelstad; [2013]
   Nyckelord :JUICE; noise; quasi-thermal noise; QTN; Nyquist noise; shot noise; Langmuir probes; electric field probes;

   Sammanfattning : The noise in the Langmuir Probe and Plasma Wave Instrument (LP-PWI) on board ESA:s future Jupiter satellite JUICE (Jupiter ICy Moons Explorer) was investigated. Thermal Johnson-Nyquist noise and shot noise, caused by fluctuations in the probe-plasma currents, were combined with the quasi-thermal noise (QTN) due to thermal fluctuations in the electric field in the plasma, using a small signal equivalent circuit model. LÄS MER