TYPE-I RADIO-BURSTS DEFLECTED BY LOWER-HYBRID WAVES

What are the observational effects if type I bursts are deflected by l ower-hybrid waves? The deflection creates an elliptical radio mirage, with the direct source at one end of the minor axis. Unlike a 'scatter ing disk', the mirage has considerable polarization structure which sh ould be observable at high angular resolution. The lower-hybrid waves have four attractive features to explain existing observations of type I bursts: they naturally yield zero polarization for limb bursts; the y preserve a high directivity even for limb bursts; they can explain t he observed constancy of polarization during partially polarized burst s; and they depolarize at a sufficient height so that the resulting tw o circular polarizations arrive nearly simultaneously, as observed. Th e small time interval between the arrival of the two polarizations req uires that we normally observe only the mirage and that the source be asymmetric with respect to azimuth around the magnetic field. The wave s appear to be restricted to the vicinity of type I sources.