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7th LOIS Workshop
June 16-18, 2008 | Växjö, Sweden
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Arranged by
LOIS Space Centre,
Växjö and PHISP,
IRF, Uppsala In collaboration with Växjö University and Videum Science Park Sponsored by CDP, Uppsala University, IBM Sweden and the Swedish National Space Board |
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Thomas Leyser
tbl@irfu.se
Swedish Institute of Space Physics (IRF)
Uppsala, Sweden
Abstract
Experimental results are presented of pumping ionospheric plasma with a
powerful radio wave carrying orbital angular momentum (OAM).
The experiments were performed at the High frequency Active Auroral
Research Program (HAARP) near Gakona, Alaska, in February 2008.
The pumped plasma turbulence was diagnosed by measuring on the ground
optical emissions as well as stimulated electromagnetic emissions (SEE)
with frequenices near that of the pump frequency.
Optical emission show a ring-shaped emission region when the pump beam
carries OAM, consistent with the ring-shaped pump beam.
Spectral features of SEE that are attributed to Langmuir turbulence are
very well developed for a regular pump beam configuration but are
significantly weaker when the beam carries OAM in which case upper
hybrid turbulence dominates the SEE.
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