Silicon vidicon spectrometry and its infrared capabilities for solar research.

A rapid-scanning silicon vidicon spectrometer is described; its sensitivity extends from 300 nm to 1080 nm, where even at that wavelength it has enough sensitivity to allow observation under eclipse conditions of a pair of forbidden spectral lines from twelve-times ionized iron that are sensitive indicators of the electron density in the solar corona. Past observational work on these ir lines is reviewed, and our vidicon observations made during the 1973 total solar eclipse are discussed. The vidicon target, the scanning procedure, and the advantages of the spectrometer are described.