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- Moen, J., Holtet, J.A., Pedersen, A., Lybekk, B., Svenes, K., Oksavik, K., Denig, W.F., Lucek, E., Søraas, F. and André, M.
(författare)
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Cluster boundary-layer measurements and optical observations at magnetically conjugate sites.
- 2001
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Ingår i: Annales Geophysicae. ; 19:6, s. 1655-1668
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Tidskriftsartikel (refereegranskat)abstract
- The Cluster spacecraft experienced several boundary layer encounters when flying outbound from the magnetosphere to the magnetosheath in the dusk sector on 14 January 2001. The dayside boundary layer was populated by magnetosheath electrons, but not with
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| 2. |
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| 3. |
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| 4. |
- Andre, M., et al.
(författare)
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Multi-spacecraft observations of broadband waves near the lower hybrid frequency at the Earthward edge of the magnetopause
- 2001
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 19:12-okt, s. 1471-1481
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Tidskriftsartikel (refereegranskat)abstract
- Broadband waves around the lower hybrid frequency (around 10 Hz) near the magnetopause are studied, using the four Cluster satellites. These waves are common at the Earthward edge of the boundary layer, consistent with earlier observations, and can have amplitudes at least up to 5 mV/m. These waves are similar on all four Cluster satellites, i.e. they are likely to be distributed over large areas of the boundary. The strongest electric fields occur during a few seconds, i.e. over distances of a few hundred km in the frame of the moving magnetopause, a scale length comparable to the ion gyroradius. The strongest magnetic oscillations in the same frequency range are typically found in the boundary layer, and across the magnetopause. During an event studied in detail, the magnetopause velocity is consistent with a large-scale depression wave, i.e. an inward bulge of magnetosheath plasma, moving tailward along the nominal magnetopause boundary. Preliminary investigations indicate that a rather flat front side of the large-scale wave is associated with a rather static small-scale electric field, while a more turbulent backside of the large-scale wave is associated with small-scale time varying electric field wave packets.
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| 5. |
- Gustafsson, Georg, et al.
(författare)
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First results of electric field and density observations by Cluster EFW based on initial months of operation
- 2001
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 19:12-okt, s. 1219-1240
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Tidskriftsartikel (refereegranskat)abstract
- Highlights are presented from studies of the electric field data from various regions along the CLUSTER orbit. They all point towards a very high coherence for phenomena recorded on four spacecraft that are separated by a few hundred kilometers for structures over the whole range of apparent frequencies from I mHz to 9 kHz. This presents completely new opportunities to study spatial-temporal plasma phenomena from the magnetosphere out to the solar wind. A new probe environment was constructed for the CLUSTER electric field experiment that now produces data of unprecedented quality. Determination of plasma flow in the solar wind is an example of the capability of the instrument.
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| 6. |
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| 7. |
- Laakso, H., Grard, R., Masson, A., Moullard, O., Bale, S., Mozer, F., Pedersen, A., Andre, M., Eriksson, A., Gustaffson, G. and Lindqvist, P.-A.
(författare)
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Multi-point electric field observations in the high-latitude magnetosphere
- 2001
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Ingår i: Les Woolliscroft Memorial Conference Sheffield Space Plasma Meeting: Multipoint Measurements versus Theory. Proceedings (SP-492) (2001) ESA SP-492. - : Noordwijk, Netherlands. ; , s. 27-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The authors use multi-point electric field observations from the four Cluster satellites to study the dynamical behavior of the high-latitude magnetosphere on February 13-14, 2001, 20-02 UT. At 20:00 UT the vehicles enter the cusp where three satellites o
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| 8. |
- Laakso, H., et al.
(författare)
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Multi-point electric field observations in the high-latitude magnetosphere
- 2001
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Ingår i: European Space Agency, (Special Publication) ESA SP. ; , s. 27-34
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Konferensbidrag (refereegranskat)abstract
- We use multi-point electric field observations from the four Cluster satellites to study the dynamical behavior of the high-latitude magnetosphere on February 13-14, 2001, 20-02 UT. At 20:00 UT the vehicles enter the cusp where three satellites observe a 500-volt potential drop. It implies that at lower altitudes there likely exist some parallel electric fields that accelerate electrons downward and ions upward. In the following 2-3 hours the satellites move over the southern polar cap where all four satellites pass through a number of stationary, large-scale density enhancements that are associated with 200-volt potential drops. The observed events are possibly ionospheric ion outflows, triggered by geomagnetic activity. At 23:20 UT, the satellites move in the distant plasma sheet, and an hour later they have a brief encounter with the auroral region where a density cavity of a few degrees wide is observed. At the equatorward edge of the cavity, large electric fields of 100 mV/m are observed, which are likely related to an auroral arc. Similar observations are collected from all four satellites within a few minutes, but a detailed comparison reveals plenty of differences, apparently due to small spatial and temporal scale sizes. Near the perigee pass, the vehicles traverse the plasma trough near local midnight, where they all detect a ULF wave event. A preliminary analysis of the event shows that it is a resonant mode of a 120-sec period. Surprisingly the observations from four satellites are not well correlated, which suggests a short spatial and temporal scale for the event. A possible source mechanism for ULF waves at this local time sector is drifting ring current protons.
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| 9. |
- Nauen, André, et al.
(författare)
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Shot noise in tunneling through a single quantum dot
- 2004
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 70:3
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the noise properties of a zero-dimensional InAs quantum dot (QD) embedded in a GaAs-AlAs-GaAs tunneling structure. We observe an approximately linear dependence of the Fano factor and the current as a function of bias voltage. Both effects can be linked to the scanning of the three-dimensional emitter density of states by the QD. At the current step the shape of the Fano factor is mainly determined by the Fermi function of the emitter electrons. The observed voltage and temperature dependence is compared to the results of a master equation approach.
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| 10. |
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