Geometric Dependence of Articial Ionospheric Layers Driven by High Power HF-heating
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
The interaction between a high frequency electromagnetic wave and the ionosphereinduces articial heating of the ionosphere which results in the Descending Arti-cial Ionospheric Layer (DAIL) phenomenon. This thesis shows that the basic processesand environment that lead to DAIL formation can be calculated using ray-tracing techniquesand the Försterling equations. In particular, this work demonstrates that theFörsterling equations can model the enhancement of the electric field near the reflectionpoint known as swelling. As swelling crosses a certain threshold it causes Langmuir turbulencewhich excites suprathermal electrons, which will in turn ionize neutral atomsthat release more electrons, and results in DAIL formation. Previous simulations haveonly just recently been able to approximate the 2D nature of ionospheric heating but atgreat computational cost and with certain simplifying assumptions. This approach providesa rapid calculation of the electric field swelling created in these circumstances andso facilitates the further study of DAIL formation. Results show maximum swellingof the electric field near the magnetic zenith at 14.5 degrees on the order of several tens ofvolts per meter for a pump voltage of 1-2 V/m, which is in agreement with previouscomputational models as well as experiment.
Place, publisher, year, edition, pages
2014. , 40 p.
IdentifiersURN: urn:nbn:se:ltu:diva-56195Local ID: cfaa059a-d7bb-4efd-9fe3-e801c3c6c4c1OAI: oai:DiVA.org:ltu-56195DiVA: diva2:1029582
Subject / course
Student thesis, at least 30 credits
Space Engineering, master's level
Papadopoulos, DennisMilikh, GennadyShao, Xi
Validerat; 20140909 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved