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Visar resultat 1 - 5 av 25 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Calibration and quality assessment of DESCARTES : grabsampler for stratospheric tracers

   Författare :Johan Arvelius; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Adsorption; Balloon; Carboxen; CFC; Chloro-Fluoro Carbon; Grab sampling; Halocarbon; Molecular sieve; Stratospheric tracer; Tracer; Adsorption; Ballong; Carboxen; CFC; Halogeniserade kolväten; Klor-Flourkarbon; Spårgas; Stratosfärisk spårgas; Space physics; Rymdfysik;

   Sammanfattning : DESCARTES is a light-weight, balloon-borne grab sampler for stratospheric long-lived tracers developed at the University of Cambridge. 33 flights have been performed with two versions of the instrument at northern latitudes by the DESCARTES team at the Swedish Institute of Space Physics (IRF) in Kiruna during the years 1997-2000. LÄS MER

3. 2. Energization and Acceleration of Dayside Polar Outflowing Oxygen

   Författare :Sachiko Arvelius; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Solar wind-magnetosphere interactions; Magnetosphere-ionosphere coupling; O energization acceleration; O outflow; Space physics; Rymdfysik;

   Sammanfattning : This thesis deals with energetic oxygen ions (i.e. single-charged atomic oxygen ions, O+) at altitudes higher than 5 Earth radii (RE) and at latitudes above 75 (toward 90) degrees invariant latitude (deg ILAT) in the dayside polar magnetosphere observed by Cluster. LÄS MER

4. 3. Instrumentation for energetic Neutral atom measurements at Mars, Venus and The Earth

   Författare :Klas Brinkfeldt; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Energetic neutral atoms; instruments and techniques; mass spectrometry; microchannel plates; solid state detectors; solar wind interaction; planets; magnetosphere; exosphere; ring current; Space physics; Rymdfysik;

   Sammanfattning : This thesis deals with the development and calibrations of sensors to measure energetic neutral atoms (ENAs) at Mars, Venus, and the Earth. ENAs are formed in charge exchange processes between energetic, singly--charged ions and a cold neutral gas. LÄS MER

5. 4. The Auroral Large Imaging System : design, operation and scientific results

   Författare :Urban Brändström; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; Aurora; Artificial airglow; HF-pump enhanced airglow; Multistation measurements; Polar Stratospheric clouds; Radio-Induced optical emissions; Spectroscopic imaging observations; Tomography; Rymd- och plasmafysik; Space physics; Rymdfysik; rymdfysik; Space Physics;

   Sammanfattning : The Auroral Large Imaging System (ALIS) was proposed in 1989 by Åke Steen as a joint Scandinavian ground-based nework of automated auroral imaging stations. The primary scientic objective was in the field of auroral physics, but it was soon realised that ALIS could be used in other fields, for example, studies of Polar Stratospheric Clouds (PSC), meteors, as well as other atmospheric phenomena. LÄS MER

7. 5. The Neutral Particle Detector on the Mars and Venus Express missions

   Författare :Alexander Grigoriev; Stas Barabash; Brian J. Anderson; Umeå universitet; []
   Nyckelord :Space and plasma physics; ENA imaging; exosphere; magnetosphere; Mars; Venus; solar wind interaction; Rymd- och plasmafysik; rymd- och plasmafysik; Space and Plasma Physics;

   Sammanfattning : The Neutral Particle Detector (NPD) is a new type of instrumentation for energetic neutral atom (ENA) diagnostics. This thesis deals with development of the NPD sensor designed as a part of the plasma and neutral particle packages ASPERA-3 and ASPERA-4 on board Mars Express and Venus Express, the European Space Agency (ESA) satellites to Mars and Venus, respectively. LÄS MER