Photoemission on the Rosetta spacecraft
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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. More than 7800 bias voltage sweeps were analyzed and parameters such as photosaturationcurrent, spacecraft potential, photoelectron temperature and offset current were calculated from these sweeps. It is found that the photoemission is stronger on Probe 1 than Probe 2. The photosaturation currents for dierent mission phases align rather well when normalized to distance to the Sun and the solar activity, when correcting for the offset currents found on the probes the alignment became even better. The typical electron density in the photoelectron cloud is 25 cm^-3 at 1 AU and the electron temperature varies from 1 - 2 eV.
Place, publisher, year, edition, pages
2012. , 40 p.
photoemission, rosetta, langmuir probe, space
Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:uu:diva-188153OAI: oai:DiVA.org:uu-188153DiVA: diva2:576415
Bachelor Programme in Physics
2012-05-23, Häggsalen, 22:02 (Swedish)
UppsokPhysics, Chemistry, Mathematics
Eriksson, Anders, PhD