Photoelectron distribution determination from plasma line intensity measurements obtained at Nancay (France) |
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| Authors: | G Lejeune W Kofman |
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| Institution: | Laboratoire CEPHAG, Equipe de Recherche Associée au C.N.R.S.B.P. 15, 38040, G-C, France |
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| Abstract: | The plasma oscillations that can be observed by the French incoherent scatter system have small phase velocities and are excited by low energy photoelectrons, typically 2–5 eV. Consequently, the method used to determine the energy photoelectron distribution from plasma line measurements made at other observatories (e.g. Cicerone, 1974) cannot be applied here: it is necessary to chose a model energy distribution with a small number of parameters. The energy shape of the flux is assumed Maxwellian and the angular shape is assumed linear with the cosine of the pitch angle. Total flux values and mean energies are obtained as a function of altitude, in agreement with other determinations, and the difference between upshifted and downshifted plasma line intensities lead to the determination of the anisotropy of the photoelectron flux. |
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