Sökning: "Langmuir probes"

Visar resultat 6 - 9 av 9 uppsatser innehållade orden Langmuir probes.

  1. 6. Noise sources in the electric field antenna on the ESA JUICE satellite

    Uppsats för yrkesexamina på avancerad nivå, Institutet för rymdfysik, Uppsalaavdelningen; Rymd- och plasmafysik

    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

  3. 7. Photoemission on the Rosetta spacecraft

    Kandidat-uppsats, Institutet för rymdfysik, Uppsalaavdelningen

    Författare :Andreas Johlander; [2012]
    Nyckelord :photoemission; rosetta; langmuir probe; space;

    Sammanfattning : Rosetta is a European spacecraft that will rendevouz with andfollow the comet 67P/Churyumov-Gerasimenko from 2014 to 2015. Among other instruments are two Langmuir probes that measure certain plasma parameters. This study aims to describe the photoemssionon Rosetta and in particular on the Langmuir probes. LÄS MER

  4. 8. Numerical modelling of Langmuir probe measurements for the Swarm spacecraft

    Master-uppsats, Rymd- och plasmafysik

    Författare :Marco Chiaretta; [2011]
    Nyckelord :Langmuir probe; ionosphere; numerical simulation; Swarm satellites;

    Sammanfattning : This work studies the current collected by the spherical Langmuir probes to be mounted on the ESA Swarm satellites in order to quantify deviations from idealized cases caused by non-ideal probe geometry. The finite-element particle-in-cell code SPIS is used to model the current collection of a realistic probe, including the support structures, for two ionospheric plasma conditions with and without drift velocity. LÄS MER

  5. 9. Analytic modelling of Rosetta Langmuir probe measurements based on SPIS simulations

    Uppsats för yrkesexamina på avancerad nivå, Institutet för rymdfysik, Uppsalaavdelningen

    Författare :Christian Hånberg; [2011]
    Nyckelord :analytic modelling; simulation; Langmuir probe; SPIS; Rosetta;

    Sammanfattning : The Rosetta spacecraft is on route to rendezvous with the comet 67P/ Churyomov-Gerasimenko. One of the instruments onboard is the Langmuir probe instrument (LAP) developed by the Swedish Institute of Space Physics. The LAP includes two spherical probes used to measure a number of properties of the surrounding plasma. LÄS MER