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Intermediate downshifted maximum of stimulated electromagnetic emission at high‐power HF heating: A new twist on an old problem
Author(s) -
Grach S. M.,
Sergeev E. N.,
Mishin E. V.,
Shindin A. V.,
McCarrick M.
Publication year - 2015
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2014ja020423
Subject(s) - ionosphere , physics , salient , twist , power (physics) , spectral density , electromagnetic radiation , atomic physics , computational physics , optics , computer science , telecommunications , geophysics , mathematics , geometry , quantum mechanics , artificial intelligence
We report a new spectral feature of Stimulated Electromagnetic Emission (SEE) from the F region ionosphere observed during high‐power HF heating experiments at the SURA and High Frequency Active Auroral Research Program heating facilities. It is located in the SEE spectrum between the pump wave frequency f 0 and the well‐known Downshifted Maximum and thus named the Intermediate Downshifted Maximum (IDM). IDM appears at effective radiated powers (ERP) P 0 ≳ 30 MW and the pump frequencies above electron gyroharmonics,f 0 − s f ce ≳ 50 (up to 250) kHz ( s = 2, 3, 4). It mirrors the well‐known Upshifted Maximum (UM) relative to f 0 . The salient stationary and dynamic properties of IDM are described and discussed.