• Characterization of a magnetized plasma in cylindrical geometry 

      Tribulato, Giulio (Master thesis; Mastergradsoppgave, 2007-06)
      Njord is a novel plasma device in which a low-temperature plasma is produced by RF waves inductively coupled into a cylindrical, magnetized vacuum. The main part of this project is to carry out an experimental characterization of the plasma in this device. The plasma expansion and acceleration of the source plasma into the main chamber will be of specific interest. The ultimate aim will then be to ...
    • A theoretical study of the coupling between minor ions and protons in the solar transition region 

      Byhring, Hanne Sigrun (Master thesis; Mastergradsoppgave, 2007-06-01)
      We have used a numerical model to calculate the flow velocities of six minor ion species, using two different background models for the fast solar wind, one with a slow expansion, and one with a very rapidly expanding geometry. By comparing the flow velocity of the minor ions and the protons, we have investigated the degree of coupling between minor ions and the background solar wind in the solar ...
    • Spectral observations of Polar Mesospheric Summer Echoes (PMSE) 

      López Muñoz, Aquilino (Master thesis; Mastergradsoppgave, 2007-06-15)
      We present spectral measurements of PMSE under the influence of HF heating cycles. The data has been obtained with EISCAT VHF radar, during the EISCAT campaign 2004 in Tromsø. Examples where the PMSE overshoot appears when the electrons are heated with a specific cycle are shown. A detailed analysis of PMSE spectral width during the heating cycles concluded that there is no evidence of a possible ...
    • Multifractals and their application to geospace data 

      Østvand, Lene (Master thesis; Mastergradsoppgave, 2008-06-02)
      In this thesis I first introduce multifractal theory and mathematical concepts for multifractal analysis. Different methods for different uses are described, with focus on a differentiating between coarse and fine theory approaches. Methods for analysing time series are also described, more specificly a direct method based on the coarse theory analysis, the wavelet transform modulus maxima ...
    • Plasma line studies in relation to Naturally Enhanced Ion Acoustic Lines (NEIALs) 

      Knutsen, Joachim Sveia (Master thesis; Mastergradsoppgave, 2008-06-02)
      New to the ESR common programmes is the inclusion of plasma lines along with the standard ion power density spectrum. Using data from the IPY common programme, a programme that has been run all through the International Polar Year, we have gone through large amounts of analysed data trying to find periods in time that fulfils the known criteria for finding Naturally Enhanced Ion Acoustic Lines ...
    • Review and test of funnel shape geometries in solar wind acceleration 

      Trollebø, Robert (Master thesis; Mastergradsoppgave, 2009-12-15)
      The origin and heating of the solar wind is still a puzzle. We review in this study the idea that the solar wind originates in coronal funnels. We place emphasis on the fast solar wind. This study provides primarily a historic overview over the development of the idea of funnel expansion. We present examples of recent solar wind studies that investigate the funnel geometry. These studies include ...
    • Na lidar measurements during the ECOMA/Geminids campaign with focus on Na peak density and temperature 

      Østerpart, Jørgen Olai Kristensen (Master thesis; Mastergradsoppgave, 2011-02)
      Using a resonance lidar, atomic Na (sodium) can be observed in the 80-110 km altitude range of the atmosphere. Na belongs to the alkali metal group and is highly reactive, so one could expect that it would quickly react with other particles and leave its atomic state. Its actual behaviour however includes the formation of relatively dense layers which, from the perspective of a stationary lidar, ...
    • Air temperature at 90 km altitude in the Artic obtained using meteor radar : validation, characterization and climate change. 

      Kluken, Lars Grytbakk (Master thesis; Mastergradsoppgave, 2011-09-30)
      Temperatures at 90 km altitude above Ramfjordmoen (69°N, 19°E) have been obtained with the Nippon/Norwegian Tromsø Meteor Radar. The temperatures have been derived from meteor radar decay rates using two techniques: the pressure based and the temperature gradient based methods. The results have been compared to the Microwave Limb Sounder (MLS) instrument on board the Aura spacecraft. It was found ...
    • Influence of Meteoric Aerosol particles on the Charge Balance in the Upper Mesosphere During ECOMA 2010 

      Svendsen, Åse (Master thesis; Mastergradsoppgave, 2011-12-15)
      This work is focused on the three sounding rocket launches during the ECOMA Geminids campaign in December 2010: One before the Geminids meteor shower, one at its peak and one some days after the peak. In this work, the main emphasis is on analyzing the results from electron and ion probes on the rockets, obtaining electron and ion density profiles, and comparing them with the measurements of meteoric ...
    • On the internal physical conditions in dust probes: transport, heating and evaporation of fragmented dust particles 

      Antonsen, Tarjei (Master thesis; Mastergradsoppgave, 2013-12-13)
      We study the conditions within, and dynamics of fragmented mesospheric dust particles inside, the Faraday-cup type dust probe MUDD using numerical simulations with a dedicated model. The transport of singly charged fragments from impacting NLC particles on the main grid in MUDD, have been calculated on the basis of supplementary models of the neutral gas conditions and electric field structure within ...
    • Arctic Cirrus Clouds: A Comparison of Properties Derived from Measurements by Ground-Based and Spaceborne Lidar Systems 

      Hanssen, Ingrid Margrethe Vestnes (Master thesis; Mastergradsoppgave, 2015-12-15)
      The purpose of this thesis is to investigate Arctic cirrus clouds. In this work, data from the ground-based lidar system at ALOMAR, Andøya Space Center. and the spaceborne lidar onboard the CALIPSO satellite is used. Cirrus clouds are an important factor in modeling climate changes, which is one of the major research fields of this time. Most of the cirrus cloud research concentrates on investigating ...
    • Automatic Detection of Naturally Enhanced Ion-Acoustic Lines in EISCAT data 

      Mikalsen, Kristian (Master thesis; Mastergradsoppgave, 2016-06-01)
      Naturally Enhanced Ion-Acoustic Lines (Neials) are small-scaled and short-lived phenomena in the ionosphere, which is widely researched internationally. At present, the search for Neials is a tedious task that has to be done through visual inspection. This is often a time-consuming process and limits the research on Neials. By automating the means of locating the Neials, the access to them will be ...
    • Installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC) 

      Dyrland, Karianne (Master thesis; Mastergradsoppgave, 2016-12-15)
      The primary focus of this thesis is the installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC). The goal is that the chamber can be used to test satellite and sounding rocket instrumentation, thus be capable of producing ionospheric plasma conditions, along with an ion beam that can simulate the velocity of a rocket or satellite relative to the ...
    • Beam and plasma properties downstream from positively biased source chamber 

      Osnes, Sindre (Master thesis; Mastergradsoppgave, 2017-06-06)
      We study the effect of changing the separation grid bias in a double plasma device from -50 V to the same bias as the anode in the source chamber, 115 V on the plasma and beam parameters downstream in the target chamber. Two different probes were used to analyze the downstream plasma. We used an RFEA-probe to obtain information about the ions, such as the ion energy distribution and we constructed ...
    • Plasma cloud detection and diagnostics from arcing by conditional averaging 

      Nilsen, Kenneth (Master thesis; Mastergradsoppgave, 2017-06-06)
      Plasma cloud formation from arcing is experimentally studied. The arcs are formed by a high voltage set-up in the space simulation chamber at UiT. The plasma clouds are observed as large structures in the time series recorded by Langmuir probe and reference probe. By using the method of conditional averaging, the structures are accentuated. The electron cloud formed by arcing was found to be ...
    • Estimating thermospheric neutral densities using ISR-observations during active HF-radio wave ionospheric heating experiment 

      Pedersen, Marcus Nicolai (Master thesis; Mastergradsoppgave, 2017-12-15)
      In this study we present a method to estimate neutral thermospheric densities using ISR-observations following a sequence of high-frequency radio wave ionospheric heating modi cations in the vicinity of the ionosphere peak density altitude (hmF2), and the results from two different days of observations with low geomagnetic activity levels (AP<4) that are compared to the MSIS model. Slight ...
    • Survey and simulation of space debris using EISCAT UHF 

      Røynestad, Elisabeth Kristina (Master thesis; Mastergradsoppgave, 2018-06-01)
      This thesis starts with a review of the evolution of space debris, what is consists of, how it is made, how it is detected and tracked, and why it is such an important topic. Some of the worst collisions have contributed to causing 49% of the total space debris. If the launch rate continues, the "Kessler Syndrome" might become a reality destroying our future outlook for space communication and ...