Measuring Electron Density in Coronal Active Regions - Part Two - a Multichannel Coronagraph with a Photoelectric Spectrograph and a Reflex Monitor at Lambda 5303A
In order to study the electron density at the scale of the most encountered structures in coronal active regions a new multichannel coronagraph associated with a photoelectric spectrograph is now used at the Pic-du-Midi Observatory. In its quasi-routine mode this instrument, which is described in this paper, works with a 30″ field aperture in a parallel manner with aK-polarimeter. On each observed region it obtains maps of intensities of theλ λ3388, 10747, and 10798 Å emission lines due to Fe xiii ion. Each measurement point is associated with a quasi-simultaneous image of the emission corona structures viewed in the light of theλ5303 Å line of Fe xiv. Three examples of observations are given and the capabilities are discussed. Measuring electron density in coronal active regions. II A multichannel photoelectric coronagraph with a photo-electric spectrograph and a reflex monitor atλ5303 Å.