NEPOSREDNA DETEKCIJA KOSMIČKE PRAŠINE RADIO - UREĐAJIMA SVEMIRSKIH LETILICA

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NEPOSREDNA DETEKCIJA KOSMIČKE PRAŠINE RADIO - UREĐAJIMA SVEMIRSKIH LETILICA

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dc.contributor.advisor Issautier, Karine
dc.contributor.author Racković Babić, Kristina
dc.date.accessioned 2023-02-27T10:46:57Z
dc.date.available 2023-02-27T10:46:57Z
dc.date.issued 2022
dc.identifier.uri http://hdl.handle.net/123456789/5547
dc.description.abstract Interplanetary dust grains contain important information about the Solar System. Analyzing these particles is an important aspect of the heliosphere study. Dust impacts have been observed using radio and wave instruments onboard the spacecraft since the 1980s. The interac- tion between the impact-generated plasma cloud and antenna – space- craft system elements generates the characteristic signal waveform. The present work focuses on the detection and interpretation of the dust generated signals from radio instruments onboard various space- craft orbiting at 1 AU. In the first part of the thesis, we aim to develop a model which links the observed electric signals to the dust impact properties. We propose a new model which takes into account the effect of impact - ionization - charge collection and electrostatic-influence. Our model provides an analytical expression for the pulse. It allows us to measure the amount of total ion charge, the fraction of escaping charge, the rise timescale, and the relaxation timescale. The proposed model is simple and conve- nient for large data fitting. To validate the model, we use the Time Do- main Sampler (TDS) subsystem of the STEREO/WAVES instrument, which generates high-cadence time series of voltage pulses for each monopole. Since the beginning of the STEREO mission in 2007, we have collected all the dust events detected by S/WAVES/TDS simul- taneously on all three monopoles at 1 AU. Our study confirms that the rise time vastly exceeds the spacecraft’s short timescale of elec- tron collection by the spacecraft. Aside from electron dynamics, we also obtained interesting results regarding the cloud’s electron tem- perature. The presented model provides an effective tool for analyzing vii dust waveforms, and is applicable for different space missions which investigate the distribution of dust particles, e.g., Solar Orbiter and Parker Solar Probe. In the second part of the thesis, we focus on the interstellar dust (ISD). Interplanetary and interstellar dust are the two main dust pop- ulations at 1 AU. Our objective is to search for interstellar dust by analyzing the data sets collected by STEREO and Wind, starting from the beginning of the missions. Between 2007 and 2012, while being at the solar minimum with a solar dipole pointing southward, all three spacecraft recorded ISD flux at 1 AU. However, before and after that period, the disappearance of the interstellar component was noticeable. The observed change of the impact rate suggests that the flux of inter- stellar dust at 1 AU varies with the solar cycle. Each time the magnetic dipole field changes its polarity during the solar cycle, small interstel- lar grains experience focusing or defocusing. Consequently, the dust grains are systematically deflected either towards, or away from the solar magnetic equator plane by the solar wind magnetic field which thus affects the dust dynamics and the total interstellar dust flux in the inner heliosphere. Our study provides the first quantitative de- scription of the time variation of ISD flux at 1 AU. en_US
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dc.description.provenance Made available in DSpace on 2023-02-27T10:46:57Z (GMT). No. of bitstreams: 1 Teza_KRB.pdf: 10952714 bytes, checksum: df323912d2c2f3ce2b1fa11a34f5733b (MD5) Previous issue date: 2022 en
dc.language.iso en en_US
dc.publisher Beograd en_US
dc.title NEPOSREDNA DETEKCIJA KOSMIČKE PRAŠINE RADIO - UREĐAJIMA SVEMIRSKIH LETILICA en_US
mf.author.birth-date 1984-08-18
mf.author.birth-place Čačak en_US
mf.author.birth-country Srbija en_US
mf.author.residence-state Srbija en_US
mf.author.citizenship Srpsko en_US
mf.author.nationality Srpkinja en_US
mf.subject.area Astronomy and Astrophysics en_US
mf.subject.keywords heliosphere, dust grains, interplanetary dust, modeling, interstellar dust, analyze en_US
mf.subject.subarea Physics of Heliosphere en_US
mf.contributor.committee Onić, Dušan
mf.contributor.committee Rezeau, Laurence
mf.contributor.committee Issautier, Karine
mf.contributor.committee Onić, Dušan
mf.contributor.committee Lamy, Herve
mf.contributor.committee Mazelle, Christian
mf.contributor.committee Stalevski, Marko
mf.contributor.committee Zeković, Vladimir
mf.contributor.committee Zaslavsky, Arnaud
mf.document.pages 151 en_US
mf.document.location Beograd en_US
mf.document.genealogy-project No en_US
mf.university Belgrade University en_US

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